CEDAR RAPIDS, IOWA NEW YORK DALLAS BURBANK

Transcription

1 CEDAR RAPIDS, IOWA NEW YORK DALLAS BURBANK

2 COLLINS RADIO COMPANY CEDAR RAPIDS, IOWA, U.S.A. Reply To WESTERN DIVISION 2700 West Olive Avenue Burbank, California Victoria Mr. Broadcaster: As you leaf through this catalog, you'll see that Collins provides a complete selection of quality broadcast, speech and communications equipment. But what you can't see is evidence of Collins' complete service to broadcasters and communications men in aviation and other specialized industries. So, we'd like to tell you about it. In the first place, some of the foremost designers in the field of electronics and communications are on Collins Engineering Staff here in Burbank. And then there's Collins Sales Service Department made up of top field service engineers and technicians. These men are specialists with years of experience in the design and service of all types of radio and communications equipment. We're equally proud of our development and test laboratories, too. Many years of planning and experience have gone into selecting the equipment that makes these laboratories among the finest in the country. The Engineering Staff, the Sales Service Staff and the laboratory facilities are here, in Burbank, for one purpose only. That purpose is to serve you -to assist you in replacing obsolete or inadequate equipment -to advise you on expanding or increasing the efficiency of your present operation. Our men are experienced in broadcast and communications systems used in the West. They are, therefore, Western specialists particularly qualified to serve you, with facilities ideally located in the West for prompt and convenient service. Whether you are in the Broadcasting industry or in Communications for other industries requiring the utmost in electronic precision and dependability, you can be sure Collins is completely staffed and equipped to provide you with the best in service. Collins leadership in AM Broadcast Equipment design has always been recognized. In the past...the present...and in the future...look to Collins for the... BEST IN BROADCAST! Please feel free to call on us at any time. ek COLLINS OF BURBANK

3 1 1 1, a 1 I I I Ì I I I see you at the NARTB May 23 through 27 Palmer House, Chicago See Collins new TV relay equipment simultaneously relaying both video (NTSC standard) and audio information on a common RF channel in the6, megacycle band. See how provisions can be made for one or two high fidelity audio program channels plus a two -way telephone channel Besides this informative demonstration you'll see Collins' complete broadcast line - transmitters, remote control systems, studio and speech equipment. Don't miss the Collins booth at the NARTB Convention. Exhibition Hall 1 I r--- _ -_J Booth 4 I -- i 1I I I I I I I I 1 Entrance COLLINS RADIO COMPANY CEDAR RAPIDS, IOWA 11 W. 42nd Street, NEW YORK Hi -Line Drive, DALLAS W. Olive Avenue, BURBANK COLLINS RADIO COMPANY OF CANADA, LTD. 74 Sparks St., OTTAWA, ONTARIO

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5 cuit complexities (See Picture 2). Extremely stable low temperature coefficient crystals in conjunction with the highly perfected oscillator design produce frequency stability well within the FCC specifications of plus or minus 20 cycles. Two crystals are employed with one of the two always available in a standby position. A selector switch provides instant choice of either crystal while the transmitter is in operation J REAR VIEW OPEN 250/100 WATT AM BROADCAST TRANSMITTER The new 300J is designed for continuous high fidelity broadcast operation at any specified frequency in the band from 540 to 1600 kilocycles or any of the high frequency broadcast bands. Facilities for power reduction from 250 watts to 100 watts are standard equipment in the 300J. The AC power is obtained from a volt single phase 50/60 cps source. All materials and components used in the 300J are of the highest Collins quality and assure long life with trouble free operation. FREQUENCY CONTROL A very high percentage of transmitter frequency failures and frequency control nuisances have been directly traceable to the crystal oven, thermostat and associated equipment. As a result of major advances in crystal stability and oscillator design, the Collins 300J eliminates the use of crystal ovens and associated thermostats, relays and cir- 2. EXCITER STIIIF TUBES High efficiency, high gain type 4-125A tetrode tubes (See Pictures 3 and 4) are used in both the modulator and the power amplifier. Extremely conservative operation is obtained with very low driving power which simplifies the over -all circuitry. Only 7 different tube types are used. Now you can keep fewer tube replacements to meet FCC requirements A 2 -Final Amplifier 2- Modulator Driver Amplifier 3 6SJ7 1- Buffer Amplifier 2 -Audio Amplifier 1 6AU6 Crystal Oscillator 2 872A High Voltage Rectifier 2 866A Low Voltage Rectifier 1 5U4G Bias Rectifier Cabinet ventilation is obtained through a fan on the lower back panel providing quiet, trouble free cooling for all components and tubes. 2

6 THERMAL TIME DELAY RELAY An instantaneous interruption of line voltage will result in no delay in returning to the air. A thermal time delay circuit automatically selects the proper delay period after short carrier interruptions. This Thermal Time Delay Relay (See Picture 6) allows you to return to the air at the earliest possible moment, cutting the off- the -air time to a minimum number of seconds. 3. MODULATOR STAGE 4. FINAL RF AMPLIFIER POWER SUPPLIES One heave duty high voltage supply is used for the modulator and final amplifier. A separate low voltage supply feeds the modulator screen grids, as well as the plates and screen grids of the other RF and audio tubes. The bias supply provides approximately 100 volts for the modulator and power amplifier bias and lesser voltages for other biasing throughout the transmitter. (See Picture 5.) 6. RELAY PANEL It CONTROLS I HIGH VOLTAGE POWER SUPPLY Momentary type filament and plate power start -stop switches are located on the front of the transmitter (See Picture 7). When the filament ON button is pressed, the filaments, blowers, bias supply and plate time delay circuit are immediately energized. At the end of the filament warm -up cycle the filament pilot light will glow, indicating readiness for application of high and low plate voltages. Manual operation of the plate button on the front of the transmitter will energize these power supplies and the plate pilot light will glow its indication of full operating conditions. If desired, the transmitter can be started by simply pressing the plate ON button. Filament, bias and plate 3

7 power will then be applied in correct sequence and with the proper time delay. Pressing the filament OFF button de- energizes all circuits. Filament and control circuits, and the high voltage plate supply are protected by toggle type magnetically operated circuit breakers. Individually adjustable overload relays are provided for the modulator and final amplifier stages. These relays are connected so that an overload removes plate power and the equipment must be re- energized manually. circuit equipment is readily accessible by removing the clip -in flush panel in the lower center of the transmitter front. No neutralization adjustments are necessary for operation at any frequency in the standard broadcast band. Personnel protection is provided by automatic door interlocks and gravity operated shorting bars. After the interlocks have opened, the gravity bars ground the high voltage and discharge the large filter capacitors. The lightning and arc -over protective kit, now supplied as standard equipment on the 300J, will safeguard tubes and tank components by interrupting the high voltage and low voltage plate supply primaries in event of a short circuit or flash -over in the transmitter RF output circuit. The protective relay has one set of contacts which are normally closed. The relay coil is connected in series with the monitor coil. The end of the monitor coil that connects to the relay is isolated from ground for DC by removing the ground connection and substituting a bypass capacitor. The transmitter bias supply is used as a convenient voltage source for operation of the relay. When an arc -over occurs in the power amplifier output tuning network, due to lightning or any other cause, the ionized path produced by the RF voltage in the arc -over has a sufficiently low DC resistance to complete the relay coil circuit and energize the relay. As the relay operates, it removes high voltage from the transmitter and stops the arc -over. 7. FRONT PANEL CONTROLS Tuning controls on the left side of the front window: High -Low Power Switch Multimeter Switch Modulator Bias Adjustments Audio Balance Control Tuning controls on the right side of the front window: PA Plate Tuning PA Loading Crystal Selector Switch Crystal Frequency Trimmers RF Driver Audio Hum Balance RF Final Amplifier Audio Hum Balance All of the above controls are available for adjustment while the Collins 300J is in operation. AC power 8. RF AND AUDIO AMPLIFIERS 4

8 4-125A 6AÚ6 CRYSTAL OSCILLATOR 65J7 FIRST BUFFER 807 DRIVER -} í 7 POWER AMPLIFIER 4.125A 6SJ7 AUDIO DRIVER 6SJ // /-- EMI HIGH VOLTAGE LOW VOLTAGE 866A 872A BIAS - SIGNAL 5U4 BIAS SUPPLY LOW VOLTAGE SUPPLY HIGH VOLTAGE SUPPLY BLOCK DIAGRAM 866A 872A 5

9 When the arc -over no longer exists there is no path to ground for the DC relay coil current, and the relay returns to its normal position. The relay removes arc -over conditions from the output network and returns the transmitter to normal operation so quickly that usually only the click of the transmitter relays will notify the transmitter operator that an arc -over has occured. OUTPUT NETWORK A high degree of harmonic attenuation has been accomplished. The entire RF network is double shielded to reduce spurious radiation. All RF circuits are completed independent of the cabinet proper. MODULATION A simplified modulator design plus advanced circuitry has resulted in a more compact, efficient modulator. The Collins 300J can be safely operated at 100% sine -ware modulation without fear of breakdown. Conservative ratings, highest quality components and modern design all contribute to the modulation capability of the 300J. Exceptionally low audio distortion is obtained. METERING 111 For ease of operation and observation of transmitter performance the following circuits are metered: RF Line Current Final Amplifier Plate Current Final Amplifier Plate Voltage Modulator Cathode Current Final Amplifier Grid Current 807 RF Driver Cathode Current 807 Grid Current 6SJ7 Buffer Cathode Current 6SJ7 Grid Current 6SJ7 Audio Cathode Current 6AU6 Crystal Oscillator Cathode Current The meter panel is tilted at an angle for operating convenience. CABINET All tubes are visible through the front window and all tuning controls are located on the front of the transmitter. One vertical door, located on each side of the front window, provides access to the various controls and adjustments. The filament and plate power switches and their associated indication lights are located below these doors on the front of the transmitter. Double doors on the rear of the cabinet provide instant access to the interior of the equipment. A "clip -in" panel below the window covers the compartment in which the time delay circuits, the plate relay and the primary terminal block are located. The top panel on the front of the transmitter can be removed (See Picture 9) by releasing two screws. Thus, the meters are readily accessible for any necessary maintenance. MONITOR CONNECTIONS Readily accessible coaxial monitor connections are provided for both modulation and frequency monitors. In addition, a direct monitor speaker connection is provided to allow on- the -air monitoring from the transmitter. A monitor amplifier system also may be fed from this termination. 9. METER PANEL This ruggedly constructed cabinet is finished in an attractive high gloss two -tone grey enamel. Streamlined polished chrome styling adds to the modern appearance and results in a transmitter of striking eye appeal. 6

10 .. B-4.,,,,, Connectors. B-1 B-3 C-I C -2 C-3 I: 0-2 D-1 D-3 E-1 2 E E 3 F -I F-2 s F-3 G-I elign H-1 'CMS G-4 D-4 F E 4 E5 F- 4 G-3 B -1 B -2 B -3 B4 C -1 C -2 C -3 C-4 D -1 D -2 D -3 D-4 (Continued from preceding page) Cannon Type XL 3 Connectors XL-3-12 Male, cable type XL Female, cable type XL-3-12SC Male, cable type with clamp XL- 3.11SC Female, cable type with clamp XL Male, chassis, screw mtg XL-3-13 Female, chassis, screw mtg XL-3-14N Male, chassis, nut mtg XL -3.13N Female, chassis, nut mtg. Cannon Type P -3 Connectors P3 -CG-12 Male, cable type P3- CG -11S Female, cable type P3-14 Male, chassis mtg P3-13 Female, chassis mtg P3-36-2G Male, dual, wall outlet type P3-35-2G Female, dual, wall outlet type P3-36 Male, single, wall outlet box type P3-35 Female, single, wall outlet box type Hubbell 3 Prong Polarized 3 Connector Male, cable, heavy duty type Male, cable type Female, cable heavy duty type Female, flush, wall mtg. type D-4 E-1 E-2 E-3 E-4 E-5 F-1 F-2 F-3 F-4 G-1 G-2 G-3 H -1 H Female, flush, with close mtg. strap (Mtg. similar to E-5) Hubbell Twist -Lock 3 Connector Male, cable, heavy duty type Female, cable, heavy duty type Male, cable type Female, cable type Male, chassis mtg Female, chassis mtg Female, flush wall mtg. type Female, flush with close mtg, strap Hubbell Midget Twist -Lock 3 Connector Male, cable type Female, cable type Female, chassis mtg Male, chassis type mtg. Hubbell Lock Twist -Lock 3 Connector Male, cable type Female, cable type Female, flush wall mtg. type Patch and Phone Plugs Male, two conductor phone plug Male, three conductor patch plug Page 40

11 Microphones Microphone 639A-B Microphone 311 Plug Kit 0 MN So 88 Basle 9A 442A Swivel Joint Jack The 633A is non- directional or may be given directivity by use of the 8B baffle. For non- directional use the microphone is mounted vertically on a stand or suspended by its cordage. Impedance: Approximately 20 ohms. Works into 25 to 50 ohms. Frequency response: 40 to 10,000 cps. Power output level: 59 dbm for a sound pres- sure of 10 dynes per square centimeter. Experience indicates that approximately ten dynes per square centimeter sound pressure is produced at conversational level three feet from the microphone. Mounting: Both floor and desk stands are avail- 712A Adapter 713A Adapter ALTEC- " ESTERN DYNAMIC MICROPHONE 24A Mounting IIA Suspension Mounting able. For stands not listed here see complete listing at end of this section. Baffles, stands, attachments and cordage are ordered separately. Collins Part No.: A Microphone A Plug Kit B Baffle A Mounting A Adapter A Jack A Swivel Joint A Adapter Reference level 1 mw 600 ohms. **See page 33. ALTEC -WESTERN 639A, 639B CARDIOD MICROPHONES Each of these microphones is a combination of a dynmanic moving coil type pressure element and an improved ribbon type velocity actuated element. The 639A has 3 patterns selected by a screwdriver operated switch. C- cardiod D- dynamic R- ribbon The 639B has 3 additional patterns which are variations of the cardiod. Impedance: approximately 40 ohms. Works into 25 to 50 ohms. Frequency response: Essentially uniform 40 to 10,000 cps. Power output: 56 dbm* for a sound pressure of 10 dynes per sq. centimeter. This level is approximately produced at conversational level three feet from the microphone. Mounting: Either floor or desk type. Accessories and cordage are ordered separately. Collins Part No.: A Microphone The above microphone less stand, cord and accessories Reference level B Microphone 00-24A Mounting A Adapter A Jack A Adapter 00-11A Suspension Mounting mw 600 ohms. Page 41

12 . Microphones KB -2C with KS -5A Stand (extra) 77 -D 44-BX BK -1 A with KS -11A Stand (extra) RCA KB -2C A miniature velocity microphone for inside remote applications or studio work. Output impedance: 30/150/250 ohms. Effet e output level: -56 dbm I referred to one milliwatt and a sound pressure of 10 dynes per cm2). Response: 50-10,000 cps. Finish: Satin chrome. Supplied with 30 ft. of three- conductor cable. Stand shown is accessory equipment. Order separately using type identification KS -5A. Available in either gray metalustre or black. Collins Part No.: KS -5A Stand Collins Part No.: RCA 77 -D This microphone has uni- directional, bi- directional, and non -directional characteristics, adjustable by means of a slotted shaft on the rear side of the windscreen. Supplied with three position "Voice-Music" switch for selection of best operating characteristics for voice or music. Output impedance (tapped transformer: 50/250/ 600 ohms. Supplied connected for 250 ohms. Effective output level: -59 db (referred to 1 milli - watt and a sound pressure of 10 dynes per sq. cm). Response: 50 to 15,000 cycles. With variations selected by Voice -Music switch. Supplied with 30 feet, two conductor shielded cable, less plug. 1/2" pipe thread. Finish: Two -tone umber gray. Collins Part No.: RCA 44 -BX Output impedance (tapped transformer) : 50/250 ohms. Supplied connected for 250 ohms. Effective output level: -55 db (referred to 1 milli - watt and a sound pressure of 10 dynes per sq. cm). Response: 30-15,000 cycles "Music" connection. Low frequencies suppressed in "Voice" connection. Finish: Polished black and chromium. Supplied with 30 feet, two conductor shielded cable, less plug. 1/2" pipe thread. Collins Part No.: BK -1A Pressure -actuated microphone complete with 30 ft. 2 conductor shielded cable. The high- fidelity BK -1A "Commentator" pressure microphone is designed for broadcast use in AM, FM and TV stations. Its construction makes it particularly well suited for remote pickups where, if used in the open air, the modern design practically eliminates the effect of air currents. The BK -1A features a smooth response and frequency range which make it suitable for reproducing both music and speech. Non -directional or semi- directional. Output impedance: 30/250 ohms (tapped transformer). Effective output level: 52 db (referred to 1 milli - watt and a sound pressure of 10 dynes per sq. cm). Response: 60-10,000 cycles. Finish : TV Gray and Chrome. 1/2" pipe thread. Collins Part No.: KS -11A Stand Collins Part No.: Page 42

13 ,,, Microphone Desk Stands 11 1 f ' NO. 1 ALTEC- WESTERN 23A Base: 5" diameter. Height: 73/4 6 ". Finish: Altec- Western gray crinkle. '/a x 24 female thread. Collins Part No.: NO. 2 ASTATIC TYPE G Has press -to-talk lever and amphenol 3 prong female socket in top. Furnished with 8 ft. 3 conductor cord. Base: 53/46" diameter. Height: 8% ". Switch mechanism grounded thread. Collins Part No.: NO. 3 RCA MI Base: 71/2" diameter. Height: 8" to 101/2 ", adjustable. Finish: Chromium and black. 1/2" pipe thread. Collins Part No.: NO. 4 RCA 91 -A FOR 44-BX MICROPHONE Base: 7" diameter. Finish: Dark umber gray. Height: 8%" to center swing of 44 -BX microphone. 1/2" pipe thread. Collins Part No.: NO. 5 ALTEC -WESTERN 24A For use with Altec- Western microphones 633A, 639A, 639B. Base: 41/2" x 61/2" oval. Finish: Aluminum gray lacquer. % -24 thread. Collins Part No.: ALTEC -WESTERN 11A YOKE Yoke attachment with swivel for mounting Altec- Western 639A -B microphones. See listing of 639A -B and 633A microphones for mounting accessories. Collins Part No.: NO. 6 RCA 91 -B Desk stand with 3/4" and 13/4" fittings for use with RCA type 88A and 77D microphones. Fittings have t /2" pipe thread. 2 supplied, 3/4" and 13/4". Finish: Black and chromium. Collins Part No.: NO. 7 RCA MI BANQUET STAND Base: 101/2" x 3 %" folded. Base effectively 12" diameter when set up. Height: 103/4" to 243/4" adjustable. Finish: Black wrinkle and chromium. 1/2" pipe thread. Base becomes carrying case for the entire stand. Collins Part No.: Page 43

14 , Microphone Floor Stands, s s s NO. 1 RCA 90 -A This stand has a very smooth acting clutch, and does not require adjustment when height is changed. Base: 12% ". Height: 3' 8" to 6' 2" 1/2" pipe thread. Finish: Satin chromium. Collins Part No.: NO. 2 MELETRON STARBIRD MODEL 180 BOOM STAND Complete with hooks and adapters for microphones using 1,4" thread and %-27 thread. Height: 5' to 9' adjustable. Boom length: 4' to 8' adjustable. Finish: Tubing - alumilite, castings- platinum gray. Collins Part No.: NO. 3 MELETRON STARBIRD MODEL 360 Portable Folding Stand Height: 191/2" to 60" adjustable. Folds to 151/2 ". Has single hollow adapter for %-24 thread, % -27 thread, 1,2" pipe tap, and plug-in to fit all standard microphones. Finish: Tubing centerless ground and anodized. Collins Part No.: NO. 4 RCA MI SECTION STAND Height: 3' 11" to 5' (using 3 sections) 1' 6" to 2' 7" using 2 sections) Base: 10" diameter. 1/2" pipe thread. Finish: Stand- Polished chromium Base - Gunmetal crackle with satin silver stripes. Collins Part No.: NO. 5 RCA KS -3A Boom with 1/2" pipe thread. 3 locking casters. Height: 4' 6" to 8'. Boom: 4' 11" to 7' 6 ". Finish: Satin aluminum and black. Collins Part No.: Page 44

15 Speakers, JENSEN HIGH FIDELITY COAXIAL LOUDSPEAKER SYSTEMS Model H -510 (15 inch) Jensen's finest speaker. Has the new wide range acoustic lens in conjunction with the Hypex formula h -f horn, annular Diaplane low- frequency radiator and Alnico 5 magnet. Specifications Input impedance: 16 ohms (Sec also Type T -102 Transformer Assembly). Power rating: 30 watts maximum speech and music signal input. Network: Integral frequency division system. (Sec Model A -110 Control Network for accessory II -F and Level Control Facilities). Dimensions: Baffle opening, 131/2 "; O.D., 151/2"; depth 9%6 ". Model K -310 (15 inch) This is the lowest cost 15 inch coaxial speaker in the Jensen line. Quality reproduction is evident all over clie frequency range, and performance is better than many higher priced speakers. Specifications Input impedance: 16 ohms (See also Type T -102 Transformer Assembly). Power rating: 20 watts maximum speech and music signal input. Network: Integral frequency division provided. (See Model A -110 Control Network for accessory H -F and level controls). Dimensions: Baffle opening, 131/2"; O.D., 15 "; depth, 81/8 " A -110 Control Network Provides adjustable level and high- frequency range controls for Models H -510, K -410 and K -310 coaxial speakers. Mounts directly on speaker housing. Plugin connections -- no wiring changes necessary. Input impedance 16 ohms. May be used in conjunction with Impedance Adjusting Transformers. Chassis complete with network, speaker connection cord and plug, Level Control and H -F Range Control on individual 30" cables for remote mounting on cabinet, satin brass flush -type escutcheons, bar knobs and mounting screws. T -102 Impedance Adjusting Transformer This high quality transformer provides alternative input impedances of 5C0-000 and 250 ohms for Models H -510 and K -310 Coaxial Speakers. Switch on chassis gives choice of two impedance values. No wiring necessary - connecting plug is simply inserted in socket on speaker terminal panel. May he used in conjunction with Model A -110 Control Ntework. Model K -210 (12 inch ) Model K -210 combines the advantages of high fidelity reproduction, swall size and low cost. It is an excellent speaker to use where these advantages arc important. Specifications Input impedance: 8 ohms (See Z Transformer for snatching ohm lines). Power rating: 12 watts maximum rpcech and music signal input. Network: Built -in frequency dividing system. (see ST836 Control for high- frequency variation facilities). Dimensions: Baffle opening, 101/2 "; O.D., 121/2 "; depth, 6%6". ST -836 Variable Control The ST -836 is an "L" -type variable unit used for "shelving" the high- frequency response of the Model K -210 Speaker. Input impedance is 16 ohms. Furnished complete with flush -type satin brass escutcheon and bar knob. Z Matching Transformer The Z transformer mounts on the frame of the K -210 coaxial speaker and provides matching from a ohm line to 8 ohms. Two -hole mounting with 31/e" centers. Core is 1/2" x 7 /e", power handling capability 16 watts. Page 45

16 Speakers and Cabinets JENSEN "SPECIAL SERIES" PM SPEAKERS This series provides excellent high fidelity performance up to 10,000 cps. 8" Model P8 -SX with transformer Z or equivalent. 500 to 600 ohms input impedance. Collins Part No.: " Model P12 -SX, with input impedance of 600 ohms. Collins Part No.: JENSEN BASS REFLEX SPEAKER CABINETS (less loudspeakers) Jensen B -81 for 8" speaker, floor or wall mtg., brown lacquer finish Collins Part No.: Jensen H -81 corner or flat mounting cabinet for 8" speaker. Built in bass reflex. Finish: Brown opaque lacquer. Dimensions: 221/2" h, 173/4" w, 81/2" d. Collins Part No.: Jensen B -121 for 12" speaker, floor or wall mtg., brown lacquer finish Collins Part No.: Jensen D -221 for 12" speaker, floor or wall mtg., limed ash blonde finish Collins Part No.: Jensen B -151 for 15" speaker, floor or wall mtg., brown lacquer finish Collins Part No.: Jensen D -251 for 15" speaker, floor or wall mtg., satin finish walnut veneer Collins Part No.: Page 46

17 Alphabetical Index Page No. Page No. Adapters, Microphone Amplifiera Console type Isolation Limiting Monitors Pre- Program 15 22, 23 18, 23 20, 21 18, 19, 23 17, Noise and Distortion Meters Oscillators, Audio Panels Attenuator Blank Jack Meter Repeat Coil Remote 8-14 Switch and Fuse 33 Antenna Tuning Units 35 VU 25, 26 Attenuator Panels 30 Patch Cords 27 Audio Oscillators 34 Plugs, Microphone and Cable 39, 40 Battery Box 15 Power Supplies 6, 24, 25 Blank Panels 36 Amplifier 24 Boards, Terminal 31 Console 6 Cabinets 36, 46 Preamplifier 24 Rack 36 Relay 25 Speaker 46 Preamplifiers 17, 22 Chokes, Tower Lighting 36 Program Amplifiers 22 Connectors, Cable and Microphone 39, 40 Program Equalizers 28, 29 Cords, Patch 27 Rack Cabinets 36 Console Type Amplifiers 22, 23 Rack Mounted Speech Equipment 21, Console, Speech Input 1-5 Relay Power Supplies 25 Equalizers, Program 28, 29 Relay Control Units 6, 7 Isolation Amplifier 18, 23 Remote Amplifiers 8-14 Jacks 27 Remote Mixer 14 Jack Panels 27 Repeat Coil Panels 30 Lighting Chokes, Tower 36 Repeat Coil Unit 24 Lights, Warning 32 Shielded Wire 33 Limiting Amplifiers 20, 21 Signs, Warning Light 32 Meters, Noise and Distortion 34 Speakers 45 Meter Panels 26 Speaker Cabinets 46 Monitors 34 Speech Input Consoles 1-5 AM 34 Stands, Microphone 43, 44 FM 34 Switch and Fuse Panels 33 Frequency Deviation 34 Terminal Boards 31 Modulation 34 Test Equipment 34 Microphone Tower Lighting Chokes 36 Adapters 15 Transcription Turntables 39 Cable 33 Transducers 39 Connectors 39, 40 Tuning Units, Antenna 35 Stands 43, 44 Turntables, Transcription 39 Microphones 41, 42 VU Panel 25, 26 Mixer, Remote 14 Warning Lights 32 Monitor Amplifiers 18, 19, 23 Wire, Shielded Page 47

18 ,,., Type Number Index Type Page No. Type Page No. 6N -1 Program Amplifier 22 6P -1 Preamplifier 17 6Q -1 Preamplifier 22 6R -2 Isolation Amplifier 18 6S -2 Isolation Amplifier 23 6T -1 Monitor Amplifier 18 6V -2 Monitor Amplifier 23 6W -2 Amplifier 23 6X -2 Monitor Amplifier 19 8B Baffle 41 9A Swivel Joint A Altec -Western Yoke 43 12Z -2-3 Remote Amplifier A Altec- Western Stand 43 23C -1 Tower Lighting Choke 36 23D -1 Tower Lighting Choke 36 23E -1 Tower Lighting Choke 36 24A Altec- Western Microphone Stand 41, 43 26W -1 Limiting Amplifier 20, 21 42E Series Antenna Tuning Units BX RCA Microphone 42 60H -2, -3, -4 Remote Mixer 14 62A Presto Transcription Turntable 39 62E -1, -2 vu panel 25, 26 63A Presto Transcription Turntable 39 64A Presto Transcription Turntable 39 65S -2, -3, -4, -5, -6 Microphone Adapters D RCA Microphone 42 82D -7 Meter Panel 26 82T -1 Metering Panel A RCA Microphone Stand A RCA Microphone Stand B RCA Microphone Stand B -1 Switch and Fuse Panel E -3, -4 Equalizers F -1 Equalizer N -2, -4 Repeat Coil Panel P -1 Repeat Coil Unit A Shunt Matching Network K -1, -3, 4, -5, -6 Terminal Boards Meletron Starbird Boom Stand B Hewlett- Packard Audio Oscillator A Hewlett -Packard Audio Oscillator A -1, -2 Warning Light Assemblies A -1 Console B Console 4, 5 212U -1, -2, -3 Remote Amplifier 11,12 212Y Remote Amplifier 12, D Jack Panels A -1 Attenuator Panel B -1 Attenuator Panel D -1, -2, -4, -5 Relay Control Panel 6, 7 311A Plug Kit Series Hewlett -Packard Noise and Distortion Meters B Hewlett- Packard FM Monitor Meletron Starbird Stand T -1, -2, -3 Power Supply U -1, -2 Console Power Supply 6 412C -2 Battery Box F -3, -4 Relay Power Supply A Jack A Matching Transformer A Presto Reproducer Arm Rest B -1, -2 Rack Cabinets A Altec- Western Microphone A, B Altec- Western Microphones A Adapter A Adapter Daven Attenuator Network A GR FM Monitor A GR AM Frequency Deviation Monitor A GR Audio Oscillator P1 GR Range Extension Filter For A Oscillator A GR AM Modulation Monitor A GR Distortion and Noise Meter 34 A -110 Jensen Control Network 45 B -81 Jensen Speaker Cabinet 46 B -121 Jensen Speaker Cabinet 46 BK -la RCA Microphone 42 B -151 Jensen Speaker Cabinet 46 D -221 Jensen Speaker Cabinet 46 D -251 Jensen Speaker Cabinet 46 G -Type Astatic Microphone 43 H -81 Jensen Speaker Cabinet 46 H -510 Jensen Speaker 45 K -210 Jensen Speaker 45 K -310 Jensen Speaker 45 KB -2C RCA Microphone 42 KS -3A RCA Microphone 44 KS -5A RCA Microphone Stand 42 KS -11A RCA Microphone Stand 44 P8 -SX Jensen Speaker 46 P12 -SX Jensen Speaker 46 ST -836 Jensen Variable Control 45 Z Jensen Matching Transformer 45 Page 48

19 Service..,.. SERVICE AT YOUR COMMAND The Collins Radio Company maintains a Sales Service Department staffed by skilled technicians and engineers who are thoroughly experienced in the use and maintenance of Collins equipment. The Sales Service Department is prepared at all times to maintain the high standards of quality featured in Collins equipment. In addition to the staff of qualified service engineers, the knowledge and experience of the entire Engineering, Research and Development Divisions are available, to aid in special problems relating to installation and use of Collins equipment. Because the Collins main plant is centrally located it can serve the entire nation quickly. This is especially helpful when the customer orders replacement components and assemblies from our comprehensive stock. A Customers' Returned Goods Repair Section facilitates prompt and efficient analysis and repair of units returned to the factory for service. This makes it unnecessary for the customer to attempt major repairs.

20 ....._. I SPECIFICATIONS FREQUENCY RANGE kc standard. Frequencies to 24mc available... ' ;_; s POWER OUTPUT watts. FREQUENCY STABILITY 10 cps.,-; 1 ---ái.. s._. : i _., ';: 0.--.: ji, si.ì+ -' ' _ :1' I '...L.JW1 ^..=l;,?.- SCHEMATIC DIAGRAM. AUDIO FREQUENCY RESPONSE Within 1.5 db from 50 to 10,000 cps. AUDIO FREQUENCY DISTORTION Less than 3% from cps for 95% modulation, including all harmonics up to 16 kc. RESIDUAL NOISE LEVEL 6O db below 100% modulation. CARRIER SHIFT Less than 5%. RF OUTPUT IMPEDANCE ohms standard. Other impedances available. AUDIO INPUT IMPEDANCE ohms. AUDIO INPUT LEVEL 10 dhm 2 db., Pad input. AMBIENT TEMPERATURE RANGE 15 to +45 C. ALTITUDE RANGE Sea Level to 6000 feet. POWER SOURCE V single phase 50/60 cps. POWER DEMAND 1.6 kw 85% PF modulation WEIGHT Approximately 900 lbs. DIMENSIONS 38" wide, 76" high, 27" deep. 7

21 I 5M P Copyright 1953 Collins Radio Company Printed In U.S.A. To serve you better, Collins operations are nationwide. Engineering and research laboratories are maintained at Dallas and Burbank. The modern, completely air and light controlled main plant at Cedar Rapids is designed for the most efficient engineering, manufacturing and office use. Collins' expansion program has resulted in an increase in floor space from 410,000 to 735,000 square feet. In addition, the Cedar Rapids Municipal Airport and the Dallas Red Bird Airport are used as experimental stations and as headquarters for a field engineering and service v+5iln.-7 4V..surv+- "-rl MAIN PLANT, CEDAR RAPIDS cowm. RADIO co. f olllllllln, R ly{-cs-yr. WESTERN DIVISION, BURBANK NEW YORK OFFICE TEXAS DIVISION, DALLAS organization. Sales departments serve the world from the Cedar Rapids, New York, Dallas, Burbank and Knoxville offices. The entire Collins organization, management. engineering. production... personnel, is devoted entirely to the designing and manufacturing of quality radio and electronic equipment. COLLINS RADIO COMPANY, Cedar Rapids, Iowa 11 W. 42nd Street 1930 Hi -Line Drive 2700 W. Olive Avenue Dogwood Road, Fountain City NEW YORK 36 DALLAS 2 BURBANK KNOXVILLE

22 ` QD GJ LLI N S RADI O GDMPANY CEDAR RAPIDS, IOWA, U.S.A. 11 West 42nd Street New York 36, N.Y. Dogwood Road Fountain City (Knoxville), Tenn W. Olive Avenue Burbank, California 1930 Hi -Line Drive Dallas, Texas BROADCAST SPEECH EQUIPMENT CONSOLES 212A -1 - Studio Console, with wall or rack relay unit, tubes and instruction Spare Tubes for 212A -1 mounting power supply, book $2, B -1 - Studio Console, with wall or rack relay unit, tubes and instruction Spare Tubes for 212B -1 mounting power supply, 1, B -2 - Studio Console, with wall or rack mounting power supply, relay unit, tubes and instruction book Spare Tubes for 212B -2 1, REMOTE AMPLIFIERS 212Y -1 - Single Channel Remote Amplifier, with one set of tubes, A.C. power cord, canvas case and instruction book. (Cannon XL microphone connector) (See NOTES below) 212Y -2 - Same as 212Y -1 but with Cannon P3-13 microphone connector Spare tubes for 212Y -1, set 412C -2 - Battery Box, with cable, less batteries Battery kit for 412C -2 65S -2 Microphone Adapter Cord (Cannon P3- CG -11) 65S -3 Microphone Adapter Cord (Hubbell 7082) 65S -4 Microphone Adapter Cord (Hubbell 23002) 65S -5 Microphone Adapter Cord (Hubbell 7555) 65S -6 Microphone Adapter Cord (Hubbell 7484) 60H -2-30/50 Ohm Two Channel Mixer for use with 212Y Single Channel Remote Amplifier. With carrying case, conversion kit for 212Y Amplifier, and instruction (See NOTES below)

23 j 4J REMOTE AMPLIFIERS (CONT'D) e 60H -3 - Same as 60H -2 except 150 ohms 60H -4 - Same as 60H -2 except 200/250 ohms 212U -1 -Two Channel Remote Amplifier Assembly, 30/50 ohms consisting of 60H -2 Mixer and 212Y basic amplifier, with carrying case, tubes and instruction book (See NOTES below) 212U -2 -Same as 212U -1 except 150 ohms 212U -3 -Same as 212U -1 except 200/250 ohms 12Z -2 - Four Channel Remote Amplifier, 30/50 ohm input impedance, standard Cannon or Hubbell microphone connectors, with one set of tubes, batteries, power cord, canvas case and instruction book (See NOTES below) $ Z -3 - Same as 12Z -2 except 200/250 ohms Spare Set Batteries for 12Z -2/ Spare Tubes for 12Z, set 9.40 Spare Power Cord for 12Z 1.50 Spare Canvas Case for 12Z 6.75 NOTES: Stock 12Z -2 and 12Z -3 Amplifiers have Cannon Type P Microphone Receptacles. Units can be supplied with Cannon XL or Hubbell 7557 at no increase in price. A $5.00 service charge per unit applies to installation of any other receptacles. Stock 212Y -1, 60H, and 212U equipments have Cannon XL Microphone receptacles. Microphones not equipped with male plugs to match these receptacles can be modified with the Type 65S Adapter Cords listed above. If output impedances other than 600 ohms are desired on the 212Y, 212U or 12Z Amplifiers, the units can be modified at our factory providing output impedance is specified on original order. A $5.00 service charge per unit applies to modification from 600 ohms to 150 ohms output. Impedances other than 150 ohms and boo ohms can be quoted and /or supplied upon receipt of inquiries or orders. AMPLIFIERS, RACK MOUNTING, AUDIO 6P -1 - Preamplifier, with one set of tubes and instruction book Spare Tubes for 6P -1 set 6R -2 - Isolation Amplifier, with one set of tubes and instruction book Spare Tubes for 6R -2, set $ o IIIP 3.50

24 QD AMPLIFIERS, RACK MOUNTING, AUDIO (CONT'D) 6T -1 - Monitor Amplifier, 2 watt, with tubes $ Spare Tubes for 6T -1, set X -2 - Line Amplifier, with one set of tubes and instruction book Spare Tubes for 6X -2, set W -1 - Limiter Amplifier, with one set of tubes and instruction book Spare Tubes for 26W -1, set AMPLIFIERS, CONSOLE TYPE 6N -1 - Program Amplifier, with tubes Spare Tubes for 6N -1, set 9.4o 6Q -1 - Dual Channel Preamplifier, with tubes Spare Tubes for 6Q -1, set S -2 - Isolation Amplifier, with tubes Spare Tubes for 6S V -2 - Monitor Amplifier, with tubes Spare Tubes for 6V W -2 - Monitor Amplifier, with tubes Spare Tubes for 6W -2, set 5.70 POWER SUPPLIES 409T -1 - Preamplifier Power Supply, with tubes Spare Tubes for 409T -1 set T -2 - Console Mounting Power Supply with tubes Spare Tubes for 409T -2, set T -3 - Rack Mounting Power Supply, with tubes and instructions Spare Tubes for 409T -3, set U -1 - Wall Mounting Power Supply, with tubes U -2 - Rack Mounting Power Supply, with tubes Spare Tubes 409U - 1/2, set F -3 - Wall Mounting Relay Power Supply F -4 - Rack Mounting Relay Power Supply, with instructions RELAY UNITS 274D -1 - Wall Mounting Relay Unit for 212A -1 Studio Console D -2 - Wall Mounting Relay Unit for 212B -1 and 212B -2 Studio Consoles D -4 - Rack Mounting Relay Unit for 212A -1 Studio Console

25 v QD-1173 RELAY NITS (CONVD ) 274D -5 - Rack Mounting Relay Unit for 212B -1 and 212B -2 Studio Consoles - $ 106,00 274D -21- Relay Panel, less relays (Complete assembly quoted on receipt of specific requirements) RELAYS FOR USE ON COLLINS 274D -1, 2, 4, and 5 RELAY UNITS Automatic Electric 200 volt D.C. Relay. Contacts right 3C; left 2C; 1B (2C contacts for.10 amp. at 603 v AC) Automatic Electric 12 volt D.C. Relay. Contacts right 1C; left 2C Automatic Electric 6.3 volt A.C. Relay. Contact la Automatic Electric 12 volt D,C. Relay. Contact la Automatic Electric 12 volt D.C, Relay. Contacts right la, 1C; left 1B, 1D Automatic Electric 12 volt D.C. Relay, Contacts right 2C; left 1D 4, Automatic Electric 12 volt D.C. Relay. Contacts right 1C; 1D; left 1D 4, Automatic Electric 12 volt D.C. Relay. Contacts right 2C; left 2C 4.50 RELAYS FOR USE ON COLLINS 274D -21 RELAY PANEL J Relay, 200- v.d.co - Coil, - Contacts, Right 1A Relay, 12- ved.co Coil, - Contacts, Right - 1A Relay, 12- ved.co Coil, - Contacts, Right - 1C; Left - 2C Relay, 200- v.deco Coil, - Contacts, Right - 3C; Left - 2C - 5 amp, plug 1B Relay, 6.3 v.aoee Coil, Contacts, Right la 4.00 STUDIO WARNING LIGHTS 209A -1 - Flush Wall Mounting Studio Warning Lights, Complete with indicating plate and lights A -2 - Wall Mounting Studio Warning Lights, complete with indicating plate and lights 20.00

26 QD NOTE: Above warning light available with any one of the three following wordings: (a) (b) (c) "On the Air" "Standby" "On the Air" "Audition" "On the Air" "Rehearsal" RACK CABINETS AND ACCESSORIES 19G -4 - Cabinet Rack 13-1/4" Deep, 31" High, 28" Panel Space 619B -1- Cabinet Rack 18" Deep, 83" High, 77" Panel Space 619B -2- Cabinet Rack 18" Deep, 76" High, 70" Panel Space 112B -1- Switch and Fuse Panel 151K -1- Terminal Board 151K -3- Terminal Assembly, Rack Mounting $ K -4- Terminal Assembly, Rack Mounting K -5- Terminal Board, only K -6- Terminal Board /4" Blank Panel, Gray /2" Blank Panel, Gray /4" Blank Panel, Gray " Blank Panel, Gray /4" Blank Panel, Gray /2" Blank Panel, Gray /4" Blank Panel, Gray " Blank Panel, Gray 8.25 RACK MOUNTING ACCESSORIES 265D pair Jack Panel D pair Jack Panel 71.25

27 QD RACK MOUNTING ACCESSORIES (CONT`D) 265D pair Jack Panel 265D pair Jack Panel 265D pair Jack Panel T $ " Patch Cord " Patch Cord " Patch Cord " Patch Cord " Patch Cord " Patch Cord " Patch Cord Male Three Conductor Patch Plug Two Circuit Jack Two Circuit Jack Two Circuit Jack E -2 - VU Meter Panel D -7 - Meter Panel, Less meters (Complete assembly quoted on receipt of specific requirements) T -1 - Meter Panel E -3 - Single Line High Frequency Equalizer 116E -4 - Dual Line High Frequency Equalizer F -1 - Program Equalizer N -2 - Repeat Coil Panel, Less coils (Complete assembly quoted on receipt of specific requirements) N -4 - Repeat Coil Panel, complete with four coils P -1 - Repeat Coil Unit, console mounting 40.00

28 QA RACK MOUNTING ACCESSORIES (CONT'D) Thordarson line to line repeat coil $ Thordarson line to multiple line repeat coil Thordarson line to multiple line repeat coil Thordarson Bridging to line repeat coil Thordarson line to multiple line repeat coil A- 1- Attenuator Panel, incorporating two balanced "Ladder" attenuators TEST EQUIPMENTS AUDIO General Radio: (Panels finished in Collins 4E Gray) A - Audio Oscillator, Low Distortion P1- Range Extension Unit for 1301A, 2 to 15 c.p.s A - Distortion and Noise Meter Other General Radio Test Equipment ON REQUEST TURNTABLES Presto Type 63A - Transcription Turntable, with 10B Chassis, in 3A Cabinet. No Reproducer Presto Type 64A - Transcription Turntable, direct gear drive, mounted in cabinet, less reproducer Presto Type 10B - 3 Speed Transcription Turntable, Chassis only Rek -O -Kut Type B -16H - 3 Speed Transcriptive Turntable, Chassis only Rek -O -Kut Type C -7 - Console Cabinet for Type B -16H Chassis REPRODUCERS AND ACCESSORIES Altec- Western 109AA Reproducer Group Altec- Western 9A Reproducer Head Altec- Western 5A Reproducer Arm 9.70 Altec- Western KS Equalizer 19.50

29 QD REPRODUCERS AND ACCESSORIES (CONT'D) Altec- Western 9B Reproducer Head Altec-Western 171A Repeat Coil $ Altec- Western 711A Arm Rest for WE 109AA Reproducer 1.10 Gray 106SP - Playback Arm with Slide -in Cartridge Feature (3 Removable Cart ridge Clips included - -2 for G.E. Cartridges and 1 for Pickering) Gray 108B Gray Gray RPX RPJ RPJ RPJ RPJ Viscous- damped transcription arm with Slide -in Cartridge Feature (4 Removable Cartridge Clips Included - -2 for G.E. Cartridges and 2 for Pickering) 4- Position Equalizer for G.E. Cartridge (LP, 2.5 or 3.0 mil) - 4- Position Equalizer for both G.E. and Pickering Cartridges G.E. Cartridge, Replaceable Stylus (Cartridge only- Stylus not included) 1 mil G.E. Sapphire Stylus 2-1/2 mil G.E. Sapphire Stylus 2-1/2 mil G.E. Diamond Stylus 1 mil G.E. Diamond Stylus DISC RECORDERS Presto 6 -N - Recorder Chassis Presto 6 -N - Recorder in 4B Cabinet Presto 6 -N Presto 8 -N Presto 8 -N Presto 85B Presto 87B Presto 1 -D - Portable Recording Turntable, complete with Type 1B carrying case Recorder Chassis less cabinet 1, Recorder Turntable, complete with Type 4A cabinet 1, Recording Amplifier (Collins 4E Finish) Recording Amplifier and Speaker, 50 ohm input Cutting Head TAPE RECORDERS, MAGNECORD PT7 -P - Portable High Level Mixing Multi -Channel Amplifier in case PT7 -C - Console or Rack Mount Amplifier and Panel

30 @D TAPE RECORDERS, MAGNECORD (CONT'D) PT6 -AH - Recorder Mechanism, with portable case, and HI -speed forward - -- $ PT6 -AHX- Same as PT6 -AH less case PP6 -VAH- Voyager one case portable recorder and amplifier consisting PT6 -V amplifier and PT6 -AH recorder PT6 -GAHP Portable Magnecordette, complete with 10 watt amplifier and twin 8" speakers in detachable carrying case. Amplifier - speaker combination may be used separately for PA work PT6 -J - Portable Single Channel Amplifier with 10 watts Audio PT6 -M - Long playing auxiliary spooling mechanism, rack mount PT63 -AH -Same as PT6 -AH but includes extra head for monitoring from tape PT63 -AHX -Same as PT63 -AH less case PT63 -J- Portable single channel. Separate amplifiers for record, playback and monitoring from tape M8OAC - Recorder including M80C amplifier, M80A Tape Transport and connecting cables 1, MC80ACX - Same as M8OAC but less case 1, M8OACC - Console Recorder including M-80C amplifier, M -80A tape transport and connecting cables 1, Spare equalizer for Magnecord, either 7-1/2" or 15" per second A Scotch Brand Recording Tape, 1200' roll, $3,67 ea., 12 or more $3.30 ea. MICROPHONES AND ACCESSORIES ALTEC- WESTERN: 633A - Pressure Microphone A - 3- Position Cardioid Microphone B - 6- Position Cardioid Microphone GB800A- Program Stand, adjustable 45" to 75" A - Desk Stand A - Desk Stand 5.10 Starbird- Meletron Boom Stand Model B - Baffle A - Swivel A - Yoke Mounting for use with Cardioid Microphone 12.10

31 EMIL BROADCAST EQUIPMENT MIE Collins Broadcast Equipment is engineered to advanced performance standards. Operation is reliable, smooth and straightforward. Thorough consideration has been given to operating detail, in order to incorporate every possible convenience. The years of successful experience in designing and producing fine audio equipment are reflected in the confidence placed in us by many customers who have asked us to lay out their entire station facilities. We will be happy to work with you on the overall specifications of your individualized equipment. By obtaining your full requirements in broadcast equipment from us, you get not only the best individual units for your purposes, but also the assurance that you have an integrated system with superior overall performance. TRANSMITTERS ANTENNAS SPEECH INPUT CONSOLES REMOTE EQUIPMENT RACK MOUNTED EQUIPMENT TEST AND MONITORING EQUIPMENT ANTENNA ACCESSORIES RACKS AND PANELS TURNTABLES AND TRANSDUCERS COLLINS RADIO COMPANY CEDAR RAPIDS, IOWA 11 W. 42nd Street, 1930 Hi -Line Drive, 2700 W. Olive Avenue, Dogwood Rood, Fountain City, NEW YORK 36 DALLAS 2 BURBANK KNOXVILLE M-WP-Printed in U. S. A.

32 QD MICROPHONES AND ACCESSORIES (CONT'D) 311A - Plug Kit $ A - Jack for use with 639A and 639B A - Adapter for use with 639A and 639B A - Adapter for use with 22A Program Stand - RCA 44BX Velocity microphone D Polydirectional microphone BK -la Pressure microphone A Announce Stand, umber gray A De Luxe Program Stand B Desk Stand KS -11A Desk Stand for BK -la 7.50 KS -3B Boom Stand A Banquet Stand _ MI section Floor Stand - Turner Aristocrat Dynamic microphone D Dynamic microphone Velocity microphone 77 Tru.Cardioid microphone Dynamic microphone Balanced Line Dynamic microphone U9S Multi- impedance Dynamic microphone _.,., JENSEN: LOUDSPEAKERS H " 30 watt coaxial, 16 ohm K " 16 watt coaxial, 16 ohm A Control Network for above speakers -.., T Line Matching Transformer, plug -in, for above 7.95

33 QD LOUDSPEAKERS (CONT`D) K " 12 watt coaxial, 8 ohm $ ST HF Control for K -210, 16 ohm input 3.15 Z Line Matching Transformer for K =210 and P12 -SX 2.88 P8 -sx - 8" Speaker less transformer a_ ohms transformer for P8 -SX loudspeaker 1.98 P12 -SX- 12" Speaker less transformer (See transformer Z -3319) C -81-8" Speaker Cabinet (Floor or wall mounting) Specify Blonde or Mahogany H -81-8" Speaker Cabinet (Corner mounting) B " Speaker Cabinet - -m, C " Speaker Cabinet, Specify Blonde or Mahogany D " Speaker Cabinet, blonde finish D " Speaker Cabinet, Walnut veneer B " Speaker Cabinet C " Speaker Cabinet, Specify Blonde or Mahogany D " Speaker Cabinet - Blonde finish D " Speaker Cabinet, Walnut veneer U Ultrasonic High Fidelity Loudspeaker Complete with Cabinet and Speakers (Mahogany finish - Blonde available on special order) HEADPHONES Brush A -1 - Crystal, 80,000 ohms, less plug Brush A - Crystal, 30,000 ohms, less plug = 7.20 Trimm Model Magnetic, 600 ohms, with plug Trimm Model Magnetic, 17,000 ohms, with plug Trimm Model Magnetic, 600 ohms, less plug 9.57 Trimm Model Magnetic, 17,000 ohms, less plug Phone Plug

34 .93 QD CONNECTORS CANNON: P3 -CG -11S P3-CG -12S P3-13 P3-14 P3-35 P3-35-2G P3-36 P3-36-2G XL-3-11 XL- 3-11SC Female, Cable Type $ 3.78 Male, Cable Type 3.09 Female, Chassis mtg Male, Chassis mtg Female, Single, Wall outlet box type 5.49 Female, dual wall outlet type Male, Single, wall outlet box type 4.26 Male, dual, wall outlet type 8.79 Female, Cable type.93 Female, Cable type with clamp 2.04 XL-3-12 Male, Cable type XL.3-12SC Male, Cable type with clamp 2.01 xi, Female, Chassis, Screw mtg. - XL- n3-13n Female, Chassis, nut mtg..93 XL-3-14 XL-3-14N Male, Chassis, screw mtg..72 Male, Chassis, nut mtg SHIELDED WIRE & MICROPHONE CABLE Shielded single conductor, #20 AWG, stranded, 5A /ft Shielded pair, #20 solid, glass insulated, 3A Shielded pair, #20 solid, cotton insulated, 3A Same as with overall insulation, 3A Shielded pair, #20 stranded, glass insulated, 3A Shielded pair, #20 stranded, cotton insulated, 3A Same as with overall insulation, 3A ON REQUEST.05 /ft..07 /ft. ON REQUEST.05 /ft. 07 /ft

35 4 QD= SHIELDED WIRE & MICROPHONE CABLE (CONT'D' Shielded pair, #16 stranded, cotton insulated, 15A.--- -_ $.08 /ft Shielded pair, #12 stranded, cotton insulated, 20A _-.10 /ft Microphone Cable, shielded pair, Belden #8422 In even multiplies of 100 ft. In fractions of 100 ft..06 /ft..07 /ft. HIGH VOLTAGE WIRE Insulated for 15,000 volt breakdown /ft. PRICES OF ALL COLLINS MANUFACTURED EQUIPMENTS ARE F.O.B. CEDAR RAPIDS, IOWA. EQUIPMENT BY OTHER, F.O.B. SOURCE. ALL PRICES ARE EXCLUSIVE OF ANY APPLICABLE FEDERAL, STATE OR LOCAL SALES, USE OR EXCISE TAXES, AND ARE SUBJECT TO CHANGE WITHOUT NOTICE. EQUIPMENT MANUFACTURED BY OTHERS WILL BE BILLED AT PRICE IN E1'rECT AT TIME OF SHIPMENT.

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41 1 NW BROADCAST TRANSMITTER

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52 -,.w.-...",_... j cuit complexities (See Picture 2). Extremely stable low temperature coefficient crystals in conjunction with the highly perfected oscillator design produce frequency stability well within the FCC specifications of plus or minus 20 cycles. Two crystals are employed with one of the two always available in a standby position. A selector switch provides instant choice of either crystal while the transmitter is in operation V REAR VIEW OPEN 1000/500 WATT AM BROADCAST TRANSMITTER The new 20V is designed for continuous high fidelity broadcast operation at any specified frequency in the band from 540 to 1600 kilocycles or any of the high frequency broadcast bands. Facilities for power reduction from 1000 watts to 500 watts are standard equipment in the 20V. The AC power is obtained from a 208/230 volt single phase 50/60 cps source. All materials and components used in the 20V are of the highest Collins quality and assure long life with trouble free operation. FREQUENCY CONTROL A very high percentage of transmitter frequency failures and frequency control nuisances have been directly traceable to the crystal oven, thermostat and associated equipment. As a result of major advances in crystal stability and oscillator design, the Collins 20V eliminates the use of crystal ovens and associated thermostats, relays and cir- 2. EXCITER STAGE TUBES High efficiency, high gain type 4-400A tetrode tubes (See Pictures 3 and 4) are used in both the modulator and the power amplifier. Extremely conservative operation is obtained with very low driving power which simplifies the over -all circuitry. Only 7 different tube types are used. Now you can keep fewer tube replacements to meet FCC requirements A 2 -Final Amplifier 2- Modulator Driver Amplifier 3 6SJ7 1- Buffer Amplifier 2 -Audio Amplifier 1 6AU6 Crystal Oscillator 2 872A High Voltage Rectifier 2 866A Low Voltage Rectifier 1 5U4G Bias Rectifier Cabinet ventilation is obtained through a fan on lower back panel. In addition, individual blowers mounted on RF and Modulator chassis provide quiet, trouble free cooling for all components and tubes. 2

53

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60 - q EL., '., Y ^ u á.: ç á u d 3 : O. ñ ÿ o É >, ' É d ó á. v C y ÿ M > d O. O u V s O o- d p In u C uañ7 O 3 : ' la.0 W a Y CJ Q. ÿ L ì C. 4. ' % 1'7 t C Dfi E ea to W ç y C O CO p.l L u OQ L. Ç x C ä E á: - -o :a é u.l _ = x E es) ó v- ó G, V C :1 L a d? W C d 4-, 3 F d Q Cr > 2.i Y si %1 W ÿ C 6 G L, r L C y CI C -a. u = E S d : : ' _ úv `.. L C G û e e e > i ' 4... u 01 ca 0 Coi '9'9 V N GD C d ". C Y. Q O Y :C á v 3 O > :4: Y y 9 fa :L." b v E: - d O ú "' ú c os V> íi b v -0 ú u í. L v C u11 -o. :..Y a C u N. á = ú ou w C C b u afc ^ L c v.9 u E Y C IA d r. la W fd _..0 '. VO..0 Z u ÿ.6 o, cl i, G C O u C O a. X OA y ' V d ÿ á N f. ON ao 2 x O a, O u Y Ñ V C, w. C.L u r_ C.6 17 C L b d: F-Io ' ó V w 10 L u L. V., ÿ Y j i' V 49!,:: N le Ó L L n w o>. F Y dl - u ey co E. E y E C O 4.: `a' u u u ÿ0.ç. a '' --r3 Y H O dv V C.r L a C2 O L' L V d Y^> o W M > a Y W O -o C C u v H `, g, ca ó.t ç oa ÿp. CO C CI u W s ú V.ó ú CO Y a.= L Á O ro L Y....Ú.0 l ÿ a :II H V W 4; O 0 w C, CO E.. a.. v«e c' ÿ L 3 W : v w F ^ Y u.. O u p Y ñ e? ÿ C.,. d.0 E > v O E o u0 I. 3- ó ú. 5> 'C b - O. ti L ir ÿ ÿ EW C vu y a w > V R S y L a 43 O~ v C w W F v. > L w v.7 n ÿ r 0 ~v ' p ai G Y C O'. C W u 'ti la a L :o u a. E y 1 c r4 N -E. E ó E. V. d E "g O:SI

61

62 THERMAL TIME DELAY RELAY An instantaneous interruption of line voltage will result in no delay in returning to the air. A thermal time delay circuit automatically selects the proper delay period after short carrier interruptions. This Thermal Time Delay Relay (See Picture 6) allows you to return to the air at the earliest possible moment, cutting the off- the -air time to a minimum number of seconds. 3. FINAL RF AMPLIFIER w 4. MODULATOR STAGE POWER SUPPLIES One heavy duty high voltage supply is used for the modulator and final amplifier. A separate low voltage supply feeds the modulator screen grids, as well as the plates and screen grids of the other RF and audio tubes. The bias supply provides approximately 100 volts for the modulator and power amplifier bias and lesser voltages for other biasing throughout the transmitter. (See Picture 5.) 6. RELAY PANEL CONTROLS,_ 5. POWER SUPPLY Momentary type filament and plate power start -stop switches are located on the front of the transmitter (See Picture 7). When the filament ON button is pressed, the filaments, blowers, bias supply and plate time delay circuit are immediately energized. At the end of the filament warm -up cycle the filament pilot light will glow, indicating readiness for application of high and low plate voltages. Manual operation of the plate button on the front of the transmitter will energize these power supplies and the plate pilot light will glow its indication of full operating conditions. If desired, the transmitter can be started by simply pressing the plate ON button. Filament, bias and plate 3

63 1 I ó eel(. 1 U O 0 4, 4 E ú o 44 ú a ^ Y O >.. E L vc a o -0 o.b d a Y, ó > a o C d DI c OA ÿ Ç b o : y â C ro E C ê wu > B. 7, áo a u '> `...na. a. y C C ar, ; r 4 4,4% LL C O' 7 1n.0 E.y+ v.. ' to (. eta a1 v..e (V.."y. 4+ u C ".O+ O w (~a a'ÿ :ZLI 4. u y G. Ñ wv i ~ w.+ b E V cm 0 CO v C 4.) y y C.+ c ; a. w Wo pa o a L W tr, vai 'G 'ú :..E F á :.'n v F i Vl C V Arri4Oir W tid z CC I:g -p.46 v o v óñ r.. -d.a a, áa=f ; w $ C C E ú >, V (a v C''' c E C H v ' 3 7 é 0 ÿ aî úow w 7 w C QC wú a RI C C >. E o p a p w C ÿ ÿ... o o C 7 Cr.. U. y C o Y, 0 >. ÿ C,.0 '4.i V.0 C w F =?; :g ed.v - '% 7 v OA C.0 a 0 d' O a, (y 3,.C,, 7 >,; N w -0 7 íca >,. p... ó O to W Ó " y CO O Ñ p E d14 y (d a Ñ v 4 r E ú ~i (3 a T ú á w y u 'O O(c C O E y y y O t C G.4 N -, O V' Qi N 1 (7 o..- `d1 `d1 Epp Ñá y c é a ñ I E ÿ _; o w v;'6 :4 " a N a+ <1"-- Ó Ce a, O â E c 3 id o a;ri ó C 4 a N v y.. v. w 44.0 C w ú < cc l yú a y b w c -0.1 o "CI p S. o v1 E t (d V l u, Ñ 40 + d 1 W O n L V 7 E d a " 7 o i Vl L ' C o.44 A ' á ó DI V Ñ (d y o a1 " 2 4a Er" a 9 ui r' d a. v1 R V. y ' u Ç w ' it: p " (' C ca, or is..1 N M v w u 'w éo y ' c '' g, á á -CI ~ L C v( 0.. ~ 1.440V.0 d O v i (". s ; 6/? > a C p' E.. b ' (.. p a, >. a+ Vl äi Ç.2.), 'f, ú w.6 d C y o C ' 1 C i 5. á, = ÿ R Q E r a >. y Ó ro a O L m Ú d > w é v.5 a ñ.'" : iî a.. ú'w"

64 . 1 1 I = I I I I I RF I I 0 ^ FREQUENCY < -/ SELECTOR I / / l i /// / i V -001 V -002 V -301 V -302 / V -303 j / V-304 // V-305 / V -204 r --/--1 I 1f t t i t i r t 11 I i OSC. ISOLATIONI BUFFER FRED. r a I FRED. la I STAGE MULT. I, O C- 'a- I I 40 L ISSCÌLLñf6ii 11Ñ IfiJ BO Ia FRED. lal MULT. I ' Iaii 0q I FREO. d 1 MULT. I-, 20 L----J II L J 15 IO I / ó L. DRIVER POWER AMPLIFIER PLATE TUNING V A / i I 0 ANTENNA LOADING / / I / I / 52 OHM OUTPUT 1 35C C-101 ANTENNA FILTER - MODULATOR V -503 V -404 V v -403B 1-1y11806 `-r V-401A V V I 2 SI J V -504 V -405 L HIGH LEVEL V-406 rf'ft'f'fr 1 = LOW PASS TO EXTERNAL FIRST FILTER SAUDIO DIODE L TO KEY 12 AUT HIGH AUDIO -- -J PHONESR OR IMPEDANCE CLIPPER LOW-LEVEL PHASE MICROPHONE LOW PASS INVERTER SIDETONE FILTER AUDIO AUD O MODULATION OSCILLATOR DRIVER DRIVER TRANSFORMER TRANSFORMER POW AMPLI IER BLOCK DIAGRAM /

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69 r m RED /BLUE T201 " r _ 160V r- (.001 R103 -efa.. R20 _25 -r C202 N 500M qyr á 0203 ) CLOCKWISE 1 R206 R206 ANV ÓM R nia>mt a70m -- C20a ~INF R210 I70M 2oe IAF. AR.2hY'' aa --- "---- L-306/ L u ñ á / I L CÖ23.0I F 00 a 00 GREEN BLACK LI b le 9 J202 P 4 0e e1 P3o1 ó É i nnnnnn R106 AMY jnioom 2i r. C109 RI ó Gs C 312 II-II- 20NF 240V. MOO. SCREEN 300A OUTPUT TAP PUSH -TO -TALK SWITCH M00. BIAS 6.3V AC PRI. H.V. me R3O «a1w 750 /000 r o f CLOCKWISE s n C o O 1= 2 f, 8312 if met zs n :ló i 1303 Fr' E Ñ H.V. 8Io n o O T á Dn P. n

70 power will then be applied in correct sequence and with the proper time delay. Pressing the filament OFF button de- energizes all circuits. Filament and control circuits, and the high voltage plate supply are protected by toggle type magnetically operated circuit breakers. Individually adjustable overload relays are provided for the modulator and final amplifier stages. These relays are connected so that an overload removes plate power and the equipment must be re- energized manually. circuit equipment is readily accessible by removing the clip -in flush panel in the lower center of the transmitter front. No neutralization adjustments are necessary for operation at any frequency in the standard broadcast band. Personnel protection is provided by automatic door interlocks and gravity operated shorting bars. After the interlocks have opened, the gravity bars ground the high voltage and discharge the large filter capacitors. The lightning and arc -over protective kit, now supplied as standard equipment on the 20V, will safeguard tubes and tank components by interrupting the high voltage and low voltage plate supply primaries in event of a short circuit or flash -over in the transmitter RF output circuit. The protective relay has one set of contacts which are normally closed. The relay coil is connected in series with the monitor coil. The end of the monitor coil that connects to the relay is isolated from ground for DC by removing the ground connection and substituting a bypass capacitor. The transmitter bias supply is used as a convenient voltage source for operation of the relay. When an arc -over occurs in the power amplifier output tuning network, due to lightning or any other cause, the ionized path produced by the RF voltage in the arc -over has a sufficiently low DC resistance to complete the relay coil circuit and energize the relay. As the relay operates, it removes high voltage from the transmitter and stops the arc -over. 7. FRONT PANEL CONTROLS Tuning controls on the left side of the front window: High -Low Power Switch Multimeter Switch Modulator Bias Adjustments Audio Balance Control Tuning controls on the right side of the front window: PA Plate Tuning PA Loading Crystal Selector Switch Crystal Frequency Trimmers RF Driver Audio Hum Balance RF Final Amplifier Audio Hum Balance All of the above controls are available for adjustment while the Collins 20V is in operation. AC power 8. RF AND AUDIO AMPLIFIERS 4

71 4-400A, 6AÚ6 CRYSTAL 6SJ7 807 DRIVER OSCILLATOR FIRST BUFFER fó / 6SJ7 i AUDIO DRIVER /4_1/ 6SJ7 -./ my HIGH VOLTAGE LOW VOLTAGE 872A BIAS - SIGNAL 5U4 BIAS SUPPLY LOW VOLTAGE SUPPLY HIGH VOLTAGE SUPPLY BLOCK DIAGRAM 866A 872A 7;1"

72 When the arc -over no longer exists there is no path to ground for the DC relay coil current, and the relay returns to its normal position. The relay removes arc -over conditions from the output network and returns the transmitter to normal operation so quickly that usually only the click of the transmitter relays will notify the transmitter operator that an arc -over has occurred. OUTPUT NETWORK A high degree of harmonic attenuation has been accomplished. The entire RF network is double shielded to reduce spurious radiation. All RF circuits are completed independent of the cabinet proper. MODULATION A simplified modulator design plus advanced circuitry has resulted in a more compact, efficient modulator. The Collins 20V can be safely operated at 100% sine -wave modulation without fear of breakdown. Conservative ratings, highest quality components and high efficiency cooling all contribute to the modulation capability of the 20V. Exceptionally low audio distortion is obtained. METERING For ease of operation and observation of transmitter performance the following circuits are metered: RF Line Current Final Amplifier Plate Current Final Amplifier Plate Voltage Modulator Cathode Current Final Amplifier Grid Current 807 RF Driver Cathode Current 807 Grid Current 6SJ7 Buffer Cathode Current 6SJ7 Grid Current 6SJ7 Audio Driver Cathode Current 6AU6 Crystal Oscillator Cathode Current The meter panel is tilted at an angle for operating convenience. CABINET All tubes are visible through the front window and all tuning controls are located on the front of the transmitter. One vertical door, located on each side of the front window, provides access to the various controls and adjustments. The filament and plate power switches and their associated indication lights are located below these doors on the front of the transmitter. Double doors on the rear of the cabinet provide instant access to the interior of the equipment. A "clip -in" panel below the window covers the compartment in which the time delay circuits, the plate relay and the primary terminal block are located. The top panel on the front of the transmitter can be removed (See Picture 9) by releasing two screws. Thus, the meters are readily accessible for any necessary maintenance. MONITOR CONNECTIONS Readily accessible coaxial monitor connections are provided for both modulation and frequency monitors. In addition, a direct monitor speaker connection is provided to allow on- the -air monitoring from the transmitter. A monitor amplifier system also may be fed from this termination. This ruggedly constructed cabinet is finished in an attractive high gloss two -tone grey enamel. Stream - lined polished chrome styling adds to the modern appearance and results in a transmitter of striking eye appeal. 6

73 s a 1 I SPECIFICATIONS FREQUENCY RANGE kc standard. Frequencies to 18mc available. POWER OUTPUT 1000/ 500 watts. gg FREQUENCY STABILITY 10 cps. AUDIO FREQUENCY RESPONSE Within E.i i cp!á 1,]11C ifs-.

74 BROADCAST EQUIPMENT Collins Broadcast Equipment is engineered to advanced performance standards. Operation is reliable, smooth and straightforward. Thorough consideration has been given to operating detail, in order to incorporate every possible convenience. The years of successful experience in designing and producing fine audio equipment are reflected in the confidence placed in us by many customers who have asked us to lay out their entire station facilities. We will be happy to work with you on the overall specifications of your individualized equipment. By obtaining your full requirements in broadcast equipment from us, you get not only the best individual units for your purposes, but also the assurance that you have an integrated system with superior overall performance. TRANSMITTERS ANTENNAS SPEECH INPUT CONSOLES REMOTE EQUIPMENT RACK MOUNTED EQUIPMENT TEST AND MONITORING EQUIPMENT ANTENNA ACCESSORIES RACKS AND PANELS TURNTABLES AND TRANSDUCERS COLLINS RADIO COMPANY CEDAR RAPIDS, IOWA 11 W. 42nd Street, 1930 Hi -Line Drive, 2700 W. Olive Avenue, NEW YORK 36 DALLAS 2 BURBANK Dogwood Rood, Fountain City, KNOXVILLE COLLINS RADIO COMPANY OF CANADA, LTD., 74 Sparks Street, Ottawa, Ontario M -WP- Printed in U. S. A.

75 5/10 KW BROADCAST TRANSMITTER

76

77 The 5000 watt 21E and 10,000 watt 21M are clean, straight -forward electrically and mechanically designed transmitters that permit operation not only in the standard broadcast band but on short wave as well. They are supplied for any frequency from 540 kilocycles to 18 megacycles. The 21 square feet of floor space occupied by the 21E /M is 1/3 to 1/2 less than the space occupied by the average broadcast transmitter of this power output. The weight has been reduced correspondingly. Dependability, long -life, and the savings in size and weight have been achieved by taking advantage of the improved performance offered by modern tubes and components and the use of simplified circuitry design. All transformers and reactors are of the dry type, eliminating the concrete vault required with earlier transmitters using oil -filled components. The 21E /M is easily serviced and maintained, thus keeping lost air time to a minimum. Full view of all tubes is provided through plate glass windows and all important circuits are metered. Access to relays and contactors for inspection and adjustment may be gained while on the air by the easy removal of access covers on the front of equipment. A removable section at the top front of each cabinet exposes the meter panels for cleaning and maintenance. All other components are accessible through the rear doors, or rear access panels. These doors are equipped with both AC primary interlocks and high voltage shorting switches for protection of operating personnel. yo0o000000w0.o 3

78 visibility... accessibility TUBES... All tubes are visible through the front windows. CONTROLS... Tuning and metering controls are located behind four access doors on the front of the transmitter. Filament and plate power push- buttons are located below these doors on the front panel. RELAYS... Control relays are accessible through identical removable insert panels located on the lower front panel of each of the three cabinets. 4

79 DRIVER CABINET OPERATING CONTROLS operating controls... The control circuits have been designed for flexibility, operating convenience and optimum equipment protection. Pushbutton control of filament and plate power is provided. If desired, the pushbutton and indicating light circuits may be extended to a remote position. Automatic sequencing is supplied; pressing the final amplifier plate on button causes all filament, bias and plate voltages to be applied in correct sequence and with the proper time delays. Pressing the filament off button instantly removes all power except that applied to the blower motor, which continues to run for a period adjustable up to 5 minutes, and then shuts off. audio... The input to the audio system consists of a terminating pad that feeds the primary of the audio input transformer. The first audio stage employs pentode- connected 6SJ7 tubes in a push -pull Class A amplifier. Type 4-125A tubes are used in the push -pull Class A audio driver. The 4-125A audio drivers are resistance coupled to the grids of a pair of 3X3000A1, push -pull, Class AB1 modulator tubes. Approximately 12 db of feedback is provided from plates of the modulator tubes to grids of the first audio stage. DRIVER CABINET AUDIO CHASSIS thermal time delay... In keeping with the modern circuitry of these transmitters, a thermal time -delay circuit is employed. The time -versus -temperature cooling curve of this circuit closely approximates the cooling characteristics of the rectifier and amplifier filaments, thereby giving the delay circuit the ability to select the proper time interval after a carrier interruption of any given length. The cold -start delay period can be adjusted for any value between 15 and 45 seconds. However, when a short carrier interruption occurs, the delay circuit allows only enough time for the filaments to reach operating temperature before the transmitter can be returned to the air. After an instantaneous power interruption, the carrier can be returned to the air immediately. This circuit represents a considerable improvement over the oil -filled dash -pots and motor -driven time delay circuits that hold the carrier off the air for a more or less standard delay period regardless of whether the transmitter is being energized from a cold start or whether the power has been off for only a moment. DRIVER CABINET RELAY ENCLOSURE 5

80 POWER AMPLIFIER CABINET METERS POWER AMPLIFIER ODULATORS 6 POWER AMPLIFIER RELAY ENCLOSURE

81 metering Meter panels are tilted at an angle for ease of operation and observation of transmitter performance. The following circuits are metered: RF Line Current Final Amplifier Plate Voltage Final Amplifier Plate Current Modulator Plate Current Final Amplifier Grid Current Back Modulator Cathode Current Front Modulator Cathode Current Back Final Amplifier Cathode Current Front Final Amplifier Cathode Current RF Driver Line Current RF Driver Plate Voltage RF Driver Plate Current Audio Driver Cathode Current RF Driver Grid Current 807 Cathode Current 807 Grid Current 6SJ7 Cathode Current 6SJ7 Grid Current Crystal Oscillator Cathode Current Audio Amplifier Cathode Current AC Filament Primary Voltage The top panel on the front of each cabinet can be removed by releasing two screws. Thus, the meters are readily accessible for any necessary maintenance. high level modulation... Class AB, high level modulation is used employing Eimac 3X3000A1 tubes. These tubes are physically interchangeable with the 3X2500A3 tubes used in the final amplifier but have performance characteristics ideal for audio use. With Class AB, operation, the audio driver transformer and its attendant problems is eliminated. overload relays... Adjustable overload relays are furnished for the RF driver, audio driver, power amplifier and modulator stages. An overload in the RF driver or audio driver stages removes all plate voltages. An overload in the power amplifier or modulator stages causes plate power to be removed and reapplied. If the overload has cleared, the equipment then remains on the air in normal operation. However, if the overload persists or.if a second overload occurs within a 4- second period, the plate voltage is removed and must be reapplied manually. 21E AUDIO FREQUENCY RESPONSE +4 ui W +2 Ó 0 0 cc 2 tl M AUDIO FREQUENCY RESPONSE 95% MOD 1000 FREQUENCY -C PS 95% MOD 4 10, FREQUENCY - C PS 10,000 7

82

83 power supplies... Plate voltage for the modulator and final amplifier is supplied by a common high voltage supply. Bias for the modulator and final amplifier is provided by a common low voltage supply. Plate voltage for the audio driver and RF driver is supplied by a common power supply. A separate low voltage supply feeds the audio driver screens as well as the plates and screens of the other RF and audio tubes. A second bias supply provides approximately 100 volts for the audio driver and RF driver bias and lesser voltage for other biasing throughout the transmitter. voltage control... Filament voltage adjustment control, high -low power control, and a high voltage breaker control are located on the front of the center cabinet just below the window. The magnetic high voltage breaker removes the primary voltage automatically upon a heavy overload in the transformer primary circuit and can be reset immediately after the overload is cleared. POWER SUPPLY PERATING CONTROLS relay accessibility... AC power circuit equipment is readily accessible by removing the clip -in flush panels on the lower front of the transmitter cabinets. All controls are available for adjustment while the transmitter is in operation. POWER SUPPLY CABINET RELAY ENCLOSURE 9

84 . -..t. DRIVER CABINET OUTPUT NETWORK ;. I81, ti i!:::u»t}nni n.diìti ifcici-, ti,r1 t _. DRIVER CABINET RF CHASSIS a4m " ' iü;ifttfp: 4/ ti'i N DRIVER CABINET LOW VOLTAGE POWER SUPPLY 10

85 shielding... The entire RF network is double shielded to reduce spurious radiation. RF circuits are completely independent of the cabinet proper. All materials and components are of the highest Collins quality and assure long life with trouble -free operation. frequency control... Asa result of major advances in crystal stability and oscillator design, the 21E /M Transmitter has eliminated the use of a crystal oven and its associated thermostats, relays and other controls. A highly perfected oscillator design in conjunction with extremely stable, low temperature coefficient crystals has resulted in exceptionally good frequency stability. There are provisions for mounting two crystals on the RF chassis, with one of the two always available in a stand -by condition. Crystals are easily selected by means of the crystal selector switch located behind the right - hand control panel. All RF circuits of the 21E /M Transmitter are extremely straightforward and trouble -free. The oscillator, buffer and RF driver plate circuits are contained within shielded plug -in units located behind the right front access door of the driver cabinet. For frequencies in the AM broadcast band, the oscillator employs a resistive load. As the 21E /M Transmitter is also available for high frequency applications, provisions are included for replacing the resistor with a tuned tank circuit for frequency doubling. A frequency monitor connection is brought out from the grid circuit of the driver amplifier. The RF output network consists of a pi section followed by an L section and is designed to feed into impedances between 50 and 72* ohms. Harmonics are greatly attenuated in this network. There is a minimum of fundamental frequency loss between the power amplifier and transmission line. *O/her impedances are available on special order. driver power supplies... The driver unit has separate power supplies for high voltage, low voltage and bias. The high voltage supply employs two type 872A half -wave mercury vapor rectifiers in a single -phase, full -wave circuit. It supplies dc voltage for the plates of the audio drivers and the plates and screens of the RF driver tubes. The low voltage supply uses two type 866A half - wave mercury vapor rectifiers in a single -phase full - wave circuit to provide dc voltage for plates and screens of the low power stages and for screens of the audio driver tubes. The bias supply employs a 5U4G high vacuum rectifier in a single -phase, full - wave circuit. It supplies bias to the 807 amplifier, audio driver, and RF driver amplifier tubes, and dc voltage for the arc- suppression circuit. 11

86 1 ill 1 II 12

87 - - _..a output network... Special design attention has been given the RF output network in the 21E /M. A high degree of harmonic attenuation has been accomplished and the network loss between the final stage and the transmission line has been minimized. The entire RF network is double shielded to reduce spurious radiation and all RF circuits are completely independent of the cabinet proper. Another feature of the Collins 21E /M Broadcast Transmitters is the arc- suppression circuit. This circuit protects the final amplifier and RF driver tank circuits against arcs to ground due to lightning or other causes. Should such an arc occur, this circuit removes plate power until the arc is extinguished, then returns the equipment to normal operation. conversion... Conversion of the 21E into the Collins 21M 10 kilowatt Transmitter is simple and easy, and may be performed either at the factory or in the field by the customer. The modification consists principally of adding a final amplifier tube and changing certain transformers and reactors. For the customer who initially installs a 21E but desires to increase his power to 10 kilowatts at a later date, the 21M conversion kit can be easily installed between sign -off time in the evening and sign -on time in the morning. cooling system... Cabinet ventilation in the final amplifier is obtained through a blower in the base of the cabinet, providing quiet, trouble -free cooling for all components and tubes. The blower produces a high capacity at a quiet, low speed and continues to run for an adjustable period of up to five minutes after power removal. Ventilation in the other two cabinets is provided by means of circulating fans. 13

88 14

89 POWER AMPLIFIER CABINET INTERLOCKS personnel protection.. Dual interlocks, both electrical and mechanical in nature, are incorporated on each of the rear doors to provide double protection to personnel. The electrical interlocks, which are of the split V type, open primary circuits of the high and low voltage transformers whenever the rear doors are opened. The mechanical interlocks close after the electrical interlocks have opened the primary circuits. circuit protection... overload protection is provided by magnetically operated circuit breakers in the filament, blower and plate input lines. In addition, each filament transformer and the bias plate transformer are protected by suitable fuses. The power amplifier and modulator tubes and circuits are also protected by means of individual plate current overload relays. POWER SUPPLY CABINET RECTIFIER CHASSIS modulation capabilities... Simplified modulation transformer design plus advanced circuitry has resulted in a compact and efficient modulator. Conservative ratings and highest quality components contribute to the modulation capability of the 21E /M. Low audio distortion and excellent stability are obtained through the use of ample feedback in the audio system. POWER SUPPLY CABINET MODULATION TRANSFORMER 15

90 SPECIFICATIONS FREQUENCY RANGE kc standard, frequencies to 18 me available POWER OUTPUT 21E 5,500 Watts 21M-10,600 Watts FREQUENCY STABILITY 555 kc to 1605 kc ±10 cps 10 C to 50 C 1600 kc to 18 me ±0.002% +20 C to +45 C AUDIO FREQUENCY Within ±2 db from 50 to 10,000 cps measured at 95% RESPONSE modulation DISTORTION RESIDUAL NOISE LEVEL Less than 3% from 50 to 7500 cps at 95% modulation, including all harmonics up to 16 kc 55 db below 100% modulation from 0 to 30 kc 60 db below 100% modulation from 150 cycle to 7500 cps CARRIER SHIFT Less than 3% RF OUTPUT IMPEDANCE AUDIO INPUT IMPEDANCE AUDIO INPUT LEVEL TEMPERATURE RANGE ALTITUDE RANGE POWER SOURCE 75/50 ohms standard. Other impedances available 600/150 ohms + 10 dbm, ±2 db, 600 ohms input with built -in input pad. With the input pad removed, -5 dbm is sufficient for 100% modulation. 150 ohm connection of input transformer is possible when desired. +15 to +45 C ambient Sea Level to 6000 feet 208/230 V three phase 50/60 cps 50 cps on special order 16

91 s.. EN RP If WEIGHT DIMENSIONS POWER DEMAND APPROXIMATES Approximately 2700 lbs. for 21E Approximately 3000 lbs. for 21M 1051/4" wide, 76" high, 28" deep (Plate transformer extra) *5000 WATTS OUTPUT Filaments and Blower Only POWER POWER (KW) FACTOR ( %) 5000 Watts Output - No Modulation % Modulation % Modulation * 10,000 WATTS OUTPUT Filaments and Blowers Only POWER POWER (KW) FACTOR (%) 10,000 Watts Output - No Modulation % Modulation % Modulation TUBE COMPLEMENT 21E 21M 1 6AU6 Crystal Oscillator 1 6AU6 1 6SJ7 Buffer or Multiplier 1 6SJ Amplifier A Driver A 1 3X2500A3 Final Amplifier 2 3X2500A3 2 6SJ7 Audio Amplifier 2 6SJ A Driver Amplifier A 2 3X3000A1 Modulator 2 3X3000A1 1 5U4G Exciter Bias 1 5U4G 2 866A Final Amplifier Bias 2 866A 2 866A Low Voltage Plate 2 866A 2 872A Intermediate Plate 2 872A 6 872A High Voltage Plate 6 57M *21E capable of 5,500 Watts Output, 21M capable of 10,600 Watts Output 17

92 q A Bi fe D 0 O ca0up O 0 0 r- o Z v2hdia GR 4 OLES á 38 r TS R -F AND MODULATOR POWER DRIVER BAY SUPPLY TRANSMITTER RF FREO MONITOR BASE ACCESS OPENINGS REAR OF CABINET BASES PLATE TRANSFORMER PRIMARY AND SECONDARY LEADS. GROMMET HOLES OR AUDIO AND MODULATION MONITOR EADS CONNECTION SIX DIA GRORAETS RASE POWER FEED MINIMUM WIRE SIZE REQUIREMENTS' SIZE OF WIRE POWER LINE FEED FROM FUSED WALL CUTOUT THREE NO 2 RUBBER COVERED BUILDING WIRE FOR THE 21E. BOX FOR 208/230 VOLT THREE PHASE 5O/0O THREE NOD RUBBER COVERED BUILDING WIRE FOR THE 21M. CPS POWER SOURCE ONE GROUND AT LEAST NO 4 WIRE. FUSE THE 21M AT 125 AMPERES. THE 21E AT 100 AMPERES. TRANSFORMER PRIMARY LEADS - NOS RUBBER COVERED BUILDING WIRE FOR THE 21E. SIX NO4 RUBBER COVERED BUILDING WIRE FOR THE 2IM. TRANSFORMER SECONDARY LEADS THREE N0.12 OR la VOLT INSULATION TRANSFORMER FRAME ONE NO.4 BARE WIRE TO CABINET GROUND. - 24á --I AUDIO INPUT LEAD -I2 vtdia GROM1TRETS 4 OLES R -F FREQUENCY L MODULATION MONITOR FEED - INPUT AUDIO LEAD AUDIO MONITOR LEAD R -F TRANSMISSION LINE T/B NOTE. ALL DIMENSIONS ARE APPROXIMATE IN INCHES DIMENSIONS FUSED CUT our BOX OF PLATE TRANSFORMER 2IE --25q HEIGHT 31>3 --21M a ////I 202 WIDTH 242 IOá DEPTH 1247 PROVIDE ENTRY INTO FLOOR DUCT FOR 3 POWER LEADS FROM WALL CUTOUT BOX. FLOOR DUCT r OR CONDUITS FRAME MADE OF 2X 4 LUMBER AND WELL INTED A COPPER ROUND p II STRAP ATTACH TO EACH CABINET AND TO 0000 GROUND. 8 FRONT 38 SUGGESTED FONNECTIOIS MONITOR FEED- --- RG 1054,- MOUNTING FRAME SIZE OF WIRF /BU COAXIAL CABLE. RG /BU COAXIAL CABLE. SHIELDED PAIR SHIELDED PAIR OR I -S/S 50 OR 72 OHM RIGID COAXIAL CABLE FOR THE 21E. 1.5/8 50 OR 72 OHM RIGID COAXIAL CABLE FOR THE 21M. NOTE IF A DUCT IS USED TO REMOVE THE WARM AIR. EMPLOY AN EXHAUST BLOWER OF AT LEAST 1500 CFM CAPACITY. ALLOW NO BACK PRESSURE WITHIN ANY CABINET.

93

94 I t o - Z. 061-D I ( D 61E-8000g-a -I (-IF IZE-tl [VVE-7 WO ALP NLO 92E-8 ue-a vze-n -0 NO m 5 NO rl I(---- q f--- 9EE -0 LEE -D SOE -d ZIE -d r Q lä -TJ ^o'dms N O, mi olall O d-i ` a V01-1* {I O0S HI h O IVI -J a N, IOE-S Z0E-S V 0002 IJII. F SBI-a - ú I. T O ] tl 60-S bb O 1+ N a 0 a O u17-4 Ó u) ' -IF ---II -I HI. VE-7 SEI -D 4111b IF D I N) I rrir I-01 1 o0a NSI 6l I -tl ú 'ó 9S 4)1IO' FEI tl HI' I-0 OOSL 41110' E21-3 m 4)1I Ñ N Z21-l2 SII 911 -) (-II 121-D 4 N a )46E III -D i Hl y N a f OSI I F-{1 Sa-D a QI-rlr1r _ I11J1 41 O a3w I - DOOV Vl -tl OSI -tl OOOZ -1I VLI -tl One ---HI. L91-O II HI 991-J V Ann.-1I. 101-a Ó aoaqr oo-sqoj8 6TOOO _ dwtll 1-0

95

96 You get the benefits of advanced engineering in all Collins Broadcasting Equipment - transmitters, in powers of 250 watts to 10 kilowatts, speech input consoles, remote amplifiers, rack mounted speech equipment, test and control equipment, custom designed audio equipment, transducers and accessories for every need. COLLINS RADIO COMPANY CEDAR RAPIDS, IOWA 11 W. 42nd Street NEW YORK HiLine Drive 2700 W. Olive A Dogwood Road, Fountain City DALLAS 2 BURBANK KNOXVILLE COLLINS RADIO COMPANY of CANADA, LTD., 74 Sparks Street, OTTAWA 4, ONTARIO 5M WP- Printed in U. S. A.

97 e 37M FM Ring Antenna 1

98 STREAMLINED SIMPLICITY: The Collins 37M Series Ring Antennas consist of only two basic parts: (1) radiating rings and (2) connecting interring transmission line. Any number of rings, either odd or even, may be employed, providing maximum flexibility in available power gains for the requirements of the particular installation. Only one inter -element transmission line is required to feed all rings in a multiple element array. The individual radiating rings are identical mechanically and electrically. They are both shunt fed and mechanically supported by this single interconnecting feed line, which consists of modified lengths of standard RMA specification rigid coaxial transmission line of suitable size for the transmitter power being employed. The 37M terminates in a standard RMA 51.5 ohm flange connection on the bottom element of the array for coupling directly to the transmission line. LIGHT WEIGHT AND WINDLOADING: Due to the simplicity of its electrical and mechanical design, the 37M is so light and compact that the resulting dead weight and windloads are reduced to a previously unknown low for FM antennas. The aerodynamic simplicity and low weight of the 37M are achieved through the complete elimination of massive radiating elements, complex external multiple line feed systems, bulky supporting structures, and unwieldly multiple element units in the individual radiating section. Greater efficiencies can be obtained and savings made in new tower costs, erection time and maintenance expense, by installing the 37M. For maximum power gains at low weight and windloads, the 37M is unexcelled. METHOD OF MOUNTING: Two advantageous methods of mounting the 37M Antenna are available to the FM broadcaster: (1) Side mounting of the array on a corner leg of the tower offers definite advantages. Towers, either guyed or self - supporting, which previously have been considered incapable of supporting any FM antenna will in nearly all cases handle the Collins side mounting 37M. Towers which support top mounting television antenna arrays increase their usefulness with the addition of a Collins side mounting 37M array. Any number of rings may be side mounted, obviating the necessity of modifying the top of the tower or disturbing in any way the tower lighting equipment, top mounting TV radiator, or the tower proper. (2) The top or pole mounting design is available on special

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101 QD COLLI N S RADIO COMPANY CEDAR RAPIDS, IOWA, U.S. A. 11 West 42nd Street New York 36, N.Y. Dogwood Road Fountain City (Knoxville), Tenn W. Olive Avenue Burbank, California 1930 Hi -Line Drive Dallas, Texas BROADCAST EQUIPMENT PRICE SCHEDULE AM TRANSMITIhRS 300J W. AM complete with one set of tubes, two crystals, and two instruction books Spare Tubes for 300J, complete set Remote Antenna current Metering Kit for 300J Transmitter 20V /500 W. AM, complete with two crystals, one set of tabes and two instruction books Spare tubes for 20V, complete set Remote Antenna current Metering Kit for 20V transmitter 21E /1000 W. AM complete with one set of tubes, two crystals, and two instruction books Spare tubes for 21E, complete set 21M - 10,000/5,000 W. AM, complete with one set of tubes, two crystals and two instruction books Spare tubes for 21M, complete set $2, ,00 5, , , , AM MONITORING EQUIPMENT GR A - Frequency Monitor (Collins 4E panel) GR A- -- Modulation Monitor (Collins 4E panel) AM ANTENNA EQUIPMENT III 42E Tuning Unit, 250 W E -5 - Tuning Unit, 1 Kw. /500 W

102 Qp AM ANTENNA EQUIPMENT (CONT'D) 42E-5 - Tuning Unit, 5 Kw A - Shunt Fed Tuning Unit, 250 W A - Shunt Fed Tuning Unit, 1 Kw A - Shunt Fed Tuning Unit, 5 Kw C Watt Lighting Choke D Watt Lighting Choke E Watt Lighting Choke Truscon 8' x 24' Expanded Copper Mesh Ground Screen, per sheet AM PHASING EQUIPMENT & ACCESSORIES Complete custom built phasing installations quoted on receipt engineering data for direction dperational On Application Andrew 40C Phase Monitor, less leads Leads for 40C Phase Monitor, each Clarke 1080 Phase Meter: Two element Three element Four element Over Four Element On Request FM ANTENNA EQUIPMENT SIDE MOUNTED, LESS MAST TOP MOUNTED, WITH MAST Rings Mounted On Rings Mounted On 1-5/8" Line 3-1/g" Line 1-5/8" Line 3-1/8" Line 37M -1 $ $ On Application 37M On Application 37M On Application 37M On Application 37M On Application 37M On Application 37M On Application 37M o On Application DEICERS - Add per bay for deicing elements.

103 QD REMOTE CONTROL EQUIPMENT FOR COLLINS TRANSMITTERS Collins -Rust Remote Control System for Collins Type 300G, #00J, 20K, 20T, and 20V transmitters, complete with studio- and transmitter control units. Control system to remotely read the following transmitter metering readings to the control point; tower lighting current, filament voltage, final plate voltage, final stage plate current, and antenna current. The following functions will be remotely controlled at the transmitter site: tower lights "On -Off ", filament power "On-Off ", plate power "On- Off ", final stage tuning, final stage loading, and reduced power or "Tune -Up ". Equipment to include preamplifier to operate the stations frequency and modulation monitors off the air at the control point. Equipment guaranteed to meet all present requirements of the Federal Communications Commission's rules and standards for remote control operation. Equipment as described above with installation of equipment to be made by Customer (F.O.B. Cedar Rapids, Iowa). Type 300G Transmitter $2, Type 300J Transmitter 2, Type 20K Transmitter 2, Type 20T Transmitter 2, Type 20V Transmitter 2, Equipment as described above with actuators to be installed at Factory prior to shipment of transmitter (F.O.B. Cedar Rapids, Iowa). Type 300J Transmitter 2, Type 20V Transmitter 2, TOWERS AND TRANSMISSION LINE Both self -supporting and guyed towers are available to meet requirements of installation. Tower quotations will be furnished on request. Andrew Corporation transmission line, fittings and accessories can be supplied in accordance with installation requirements. Detailed quotations on both towers and transmission line are available from your nearest Collins Representative. PRICES OF ALL COLLINS MANUFACTURED EQUIPMENTS ARE F.O.B. CEDAR RAPIpS, IOWA EXCEPT FM ANTENNAS WHICH ARE F.10.B. EVANSVILLE, INDIANA; EQUIPMENT BY OTHERS, F.O.B. SOURCE. ALL PRICES ARE EXCLUSIVE OF ANY APPLICABLE FEDERAL, STATE OR LOCAL SALES, USE OR EXCISE TAXES, AND ARE SUBJECT TO CHANGE WITHOUT NOTICE, EQUIPMENT MANUFACTURED BY OTHERS WILL BE BILLED AT PRICE IN EFFECT AT TIME OF SHIPMENT.

104 0,1C0 LLI NS Speech Equipment, *0` \ \,\ \ \ 4,:xfpN A \ \. CATALOG 111

105 Speech Equipment and Accessories FOREWORD This book is prepared for your convenience in selecting equipment that will meet your requirements. The consoles, amplifiers and accessories shown and described are engineered to advanced performance standards. Their operation is reliable, smooth, and straightforward. Thorough consideration has been given to operating detail, in order to incorporate every possible convenience. The years of successful experience in designing and producing fine audio equipment arc reflected in the confidence with which many customers have asked us to lay out their entire station facilities. We will be happy to work with you on the overall specifications of your individualized equipment. By obtaining your full requirements in audio equipment from us, you get not only the best individual units for your purpose, but also the assurance that you have an integrated system with superior overall performance. Contents Section Pages SPEECH INPUT CONSOLES 1-7 REMOTE EQUIPMENT 8-15 RACK MOUNTED EQUIPMENT TEST AND MONITORING EQUIPMENT 34 ANTENNA ACCESSORIES 35, 36 RACKS AND PANELS 36 CUSTOM EQUIPMENT TURNTABLES AND TRANSDUCERS INDEX 47, 48

106 212A -1 Speech Input Console. Collins 212A -1; front view For audio control in AM, FM, and television broadcasting, the Collins 212A -1 speech input console provides simplicity of installation, convenience in operation, and maximum versatility. A novel rotating arrangement allows the entire unit to be tilted for access to the underside of the chassis without requiring additional space. The 212A can be placed right up against a window, wall, or other obstructing surface without sacrificing accessibility, or requiring external support when the chassis is tilted. Unit amplifiers are individually mounted on airplane type shock mounts. The sloping front panel provides ease of reading and hand movements. Lever type positive action switches are employed in line switching circuits, and reliable telephone type push button controls are used to connect remote lines. The step -by-step attenuators have a smooth, easy action. Facilities are provided for auditioning or rehearsing, cueing and broadcasting simultaneously from any combination of two studios, an announce booth, a control room microphone, two turntables, and any two of nine remote lines. Two program amplifiers are included in the 212A -1, making possible the feeding of two independent programs at once, or by operating the line reversal switch, providing an emergency amplifier for normal use. A spare key switch is mounted on the panel with leads appearing on the terminal strip. 212A -1 Console; top view open MI/ , Page 1

107 Speech input Console a V o f---t---f j z a a 7 212A -I Block Diagram a J r r Y Y D H I a a a a lo 0 lo "ob`n8 veo Page 2

108 Speech Input Console a r Pf!_PIPP.PJprf Telephone type push button switch FEATURES AND SPECIFICATIONS: 1. Ten independent input channels, including 6 microphone inputs and 2 low level transcription inputs (eight preamplifiers, one for each of the foregoing) and 2 channels for remote pickups. 2. Any two of nine remote lines can be selected at will. Normal connections are supplied through the switches, so that override in the monitor is possible if desired. The remote channel provides for the feedback of cue to the remote lines, as well as for tlkback. 3. Loudspeakers in all studios can be fed from the self- contained monitor amplifier, with selective talk - back circuits interlocked to prevent program interruption. Talkback from the control room is possible into any one of three studios or into the remote lines by key switch control. 4. Connections are provided for external "on the air" lights, with power furnished by the 212A -1 relay units. 5. Two vu meters are incorporated. One is bridged continuously across the program line 1. The other may be used as a vu meter for the second program amplifier, or to check (by means of a selector switch) individual circuits in the console. 6. Jacks are provided for headphone monitoring of either program amplifier. 7. The construction permits easy access to tubes, components, and wiring, without taking the console out of operation. 8. The power is external, with provision for installation of a duplicate power supply. A single supply is capable of operating the equipment with adequate safety factors for long, trouble -free service. However, if two supplies are installed, a changeover is effected automatically in case of failure of the power supply in use. One power supply and the relay unit are included in the purchase of the 212A -1. Frequency response: Microphone to line, or microphone to speaker, within 2 db total variation from 30 to 15,000 cps at normal gain control settings. Not more than ±1/2 db additional variation in frequency response over the above range at any other gain control setting. Input impedance: Microphones 30/50 or 200/250 ohms. Remote lines 150 or 600 ohms, with repeat coils self- contained. Turntables 30/50 or 200/250 ohms. Output impedance: Program line 150 or 500/600 ohms balanced. Speakers, maximum of 5, each 600 ohms. Output level: Program line vu meter adjustable, +4 to +24 dbtn* in 1 db steps. Monitor output: 8 watts. Distortion: Less than 1.0% rms harmonic distortion at normal output through line amplifier. Less than 2.0% rms harmonic distortion at 8 watts output from monitor amplifier. In addition. combination tone distortion is of the same order at the saine levels. Gain: Maximum, microphone to program line, 100 (lb; remote line to program line, 50 db. Noise level: With the gain controls adjusted for normal operation with a low level microphone input and with +16 Mini* output, but with input terminated in an equivalent resistance, the combined hum and noise in the program output is at least 65 db down. Power input: 115 volts 50/60 cycles a -c. Weight: Approx. 150 pounds. Dimensions: 42" w, 12" h, 171/2" d. Collins Part Number: See 274D -1 or 274D -4 ( pgs. 6-7) for relay unit. and 409U -1 or 409U -2 1 pg. 6) for power supply, both of which are furnished as part of this equipment. dbm: reference level 1 rim, 600 ohms. 212A1 Console tilted for servicing Page 3

109 212E Speech Input Console, 2128 Console; front view The Collins 212B -1 has the same fine constructional and operational features as the 212A -1 and differs only in that it is smaller, with fewer amplifiers and functional facilities. The 212B -1 fills the needs of the smaller station, in which operating demands are less complex, and is ideal for single studio control in larger stations. Facilities are provided for one program channel and an audition channel which functions with the self- contained monitor amplifier. The single program channel exactly duplicates one of the two channels in the 212A -1. Headphone jacks are provided across both the program and monitor outputs. Cue to remote and talkback to either of two studios or the remotes is accomplished as with the 212A -1. A line reversal switch transfers the program output to either of two lines. Four push button positions on the front panel provide utility monitor inputs, in addition to the five circuits already monitored by the push button switch -AUDITION, TURNTABLE 1, TURNTABLE 2, REMOTE and PROGRAM. FEATURES: 1. Seven independent input channels, including 4 microphone inputs, each with its own preamplifier, 2 high level transcription inputs, and a remote pickup channel. Two models are available: The 212B -1 as described. The 212B -2 includes two additional preamplifiers for low level transcription inputs. 2. Loudspeakers in all studios can be fed from the monitor amplifier, with selective talkback circuits interlocked to prevent program interruption. Talk - back from the control room into either one of two studios or into the remote lines is provided by key switch control. 3. Tube check is conveniently provided by a switch in the vu meter circuit. 4. Both the program channel and the audition channel are complete and independent. Audition may be accomplished while a program is on the air. 5. An external power supply is provided, with adequate safety factors for long, trouble -free service. Since the power supply is external, full -size highest quality components are utilized in the speech console, with compact cabinet size and with all components and wiring easily accessible. The power supply used with the 212B -1 and 212B -2 is identical with that used with the 212A -1. Sec 274D -2 or 274D -5 (pg. 7) for relay unit, and 409U -1 or 409U -2 (pg. 6) for power supply. Both are furnished as part of this equipment. The specifications of the 212B -1 and 212B -2 are identical with those of the 212A -1 except as follows: Weight: 107 pounds. Dimensions: 311/2" w, 12" h, 17%" d. Collins Part No.: B B -2 Page 4

110 I I,, 2128 Speech Input Console :r o and -2 Block Diagram HI ISO - - J ----J Ont O Page 5

111 Studio Console Power Supplies and Relay Units 409U -1 POWER SUPPLY Weight: 70 lbs., 3 oz. Dimensions: 201/2" w, 151/2" h, 10" d. Finish: Glossy black cabinet with metallic gray door. Collins Part No.: U -2 POWER SUPPLY A rack mounting power supply electrically the same as the 409U -1. An easily removable dust cover protects the wiring. Dimensions: 19" w, 14" h, 912" d. Finish: Metallic gray panel, velvet gray dust cover. Weight: 61 lbs., 12 oz. Collins Part No.: For other power supplies see pages 24 and 25. A wall mounting power supply for the 212A and 212B series consoles. It contains three supplies which furnish d -c power for preamplifiers, monitor and line amplifiers, and 12 volts for relay operation. In addition, it furnishes 6.3 volts a -e to operate all tubes in the console. The 409U -1 is a stable power supply exceptionally well filtered in high, medium and low voltages. Electrolytic capacitors in the medium voltage circuits are of the plug-in type, while oil filled paper capacitors are used in the high voltage circuits. Tapped primaries on the transformers enable operation over wide voltage ranges. Two separate supplies are included with a single (fullwave) rectifier in the medium voltage supply, and two rectifiers ( fullwave) in the higher voltage supply, wired in such a manner that program will not be stopped by a failure of one of the tubes. Contained in an attractive wall mounting case to harmonize with the 274D -1 or 274D -2 relay units, the 409U -1 can be mounted on the wall, or on the side of the operating desk. Specifications: Input: volts 50/60 cycles a -c (by varying transformer taps). Output: 140 volts 60 ma max. 325 volts d 250 ma max. 12 volts d LO amp. 6.3 volta a 10 amps. Tubes: 2-5R4GY, in high voltage supply. 1-6X5GT, in medium voltage supply. 1- Selenium rectifier in 12 volt supply. 274D -1 RELAY CONTROL, UNIT A relay control unit for use with the 212A console. It completely controls studio and control room loudspeakers, as well as studio on- off -the-air lights. Two switches on the hinged front panel control 110 volt power to the power supply and 110 volt power to the studio warning lights. Relays are protected by a dust shield held in place by two easy -to- remove Dzus fasteners. An added feature is a relay switching system with which, by the use of two power supplies, instant uninterrupted service may be effected in case of a failure. Any portion of the operating power supply, including relay and filament power, will operate the changeover. A pilot lamp indicates only when the auxiliary power supply is in use. Page 6

112 Relay Control Units, Terminals are provided for connection to all studio and control room warning lights. Five loudspeakers are also terminated at this point. The relay unit functions as a terminal point for all power connections between the supply and console. No additional relay circuits are necessary for the warning lights. Number of Relays: Five -studio loudspeakers and warning light controls. Four -power changeover relays. Input Voltage: 115 volts, 50/60 cycles. Warning Light Power: 115 volts, 50/60 cycles. Circuit breaker links are supplied for currents up to 9 amperes. Dimensions: 202" w, 151 /2" h, 10" d. Weight: 17 lbs., 9 oz. Finish: Glossy black cabinet, metallic gray panel. Collins Part No.: Warning Light Power: 115 volts, 50/60 cycles. Circuit breaker links are supplied for currents up to 9 amperes. Dimensions: 201/2" w, 11" h, 10" d. Finish: Glossy black cabinet, metallic gray door. Weight: 13 lbs. Collins Part No.: D -4 RELAY CONTROL UNIT 274D -2 RELAY CONTROL UNIT f). U. e..,-. O i fy P.!'J* d Io{ Ij- f3- *AN, i:r? ii Pr.^.- if e,. e.vrn- *p. 'I- i et.. o-.. VI f',...+- M!r. EA, : M f} y e. ty + M l. a A..),. «t 1 1 Identical with 274D -1 with the exception that it is constructed for rack mounting. An easily removable dust cover protects the wiring. Dimensions: 19" w, 8 -:j4." h, 5%" d (with dust cover). Weight: 10 lbs. Finish: Metallic gray panels, velvet gray cover. Collins Part No.: The 274D -2 is a wall mounted unit designed for use with the 212B console. It completely controls studio and control room loudspeakers, as well as studio onoff -the-air lights. and line voltage to the power supply and studio warning lights. Relays are protected by a (lust shield held in place by two easily removed Dzus fasteners. Terminals are provided for connection to all studio and control room warning lights. Four loudspeakers are also terminated at this point. The relay unit functions as a terminal point for all power connections between the supply and console. No additional relay circuits are necessary for the warning lights. Number of Relays: Four. Studio loudspeaker and warning light controls. Input Voltage: 115 volts 50/60 cycles. 274D -5 RELAY CONTROL UNIT Identical with 274D -2, with the exception that it is constructed for rack mounting. An easily removable dust cover protects the wiring. Dimensions: 19" w, 7" h, 51/2 "d (with dust cover). Finish: Metallic gray panel, velvet gray cover. Weight: 7 lbs., 3 oz. Collins Part No.: Page 7

113 12Z Remote Amplifier VOL UNITS b 16, 1 I LINE MONITOR G 12Z -2 AND 12Z -3 REMOTE AMPLIFIERS The 12Z is a prime example of Collins design ingenuity, quality and efficiency. This light- weight, small -size a -c or battery operated remote amplifier is ready to go anywhere, any time, and features double program protection, convenience and excellent performance. The input impedance of the 12Z -2 is 30/50 ohms. That of the 12Z -3 is 200/250 ohms. Otherwise the two are identical. Advanced engineering has combined four input channels with individual controls, a master control, an a -c power supply, and a self- contained battery power supply in one easily carried unit. The mixing controls are low impedance T type to give low insertion loss. The master gain control is a high im- pedance potentiometer. All controls have an attenuation of 2 db per step. A range switch and a meter switch connect a 4 inch illuminated vu meter to the proper circuit for measuring the output level in volume units, or operating voltages. A 3 db pad between the output of the amplifier and the line provides line isolation. The vu readings are taken at the front of this pad, so that when the vu meter is reading +4, the line level is +1 vu. The output switch, in 0 position, connects the output of the amplifier into a 600 ohm resistor, and the Tel terminals are across line 2 terminals. In LINE 1 position, the output of the amplifier is across line 1 terminals, and the Tel terminals are across line 2. In LINE 2 position the amplifier is across line 2, and the Tel terminals are across line 1. Page 8

114 12Z Remote Amplifier Jacks are provided for monitor headphones. The program monitor jack is across the output of the amplifier. The line monitor jack is across line 1, or across the 'fel terminals when the output switch is in LINE 2 position. The program is protected against a -c failure by automatic, instantaneous change -over to battery operation. When a -c power is restored, the amplifier may be put back on a -c operation by turning the power switch to "a -c reset," then back to "on." The change back to a -c operation is also instantaneous. and the program is not interrupted. Unit type construction provides easy maintenance. The batteries are held in place with thumb screws. The a -c power supply is removed by taking out three bolts and unplugging the unit. The amplifier is shock mounted and is also easily removable. The 12Z is supplied with a canvas carrying case which, on arrival at the location of a pick -up may be taken off entirely or opened at the front by means of a slide fastener. The front dust cover is removed by means of two ring type Dzus fasteners. An interlock switch, operated by this cover, disconnects the batteries when the equipment is not in use. A snap buttoned flap in the canvas carrying case provides access to the four microphone receptacles, power receptacle, and line connections. SPECIFICATIONS Input: Four channels, with individual controls and a master control. Construction is neat, clean and compact. The dust cover slips off easily after loosening only two fasteners. The audio amp. lifter is shockmounted Gain: Approximately 90 db. Noise level: 60 db below program level or better. Power output: 50 ntilliwatts ( +17 dime) Distortion: levels. Less that 1% at typical operating Frequency response: ±1 db 50 to 15,000 cps. Input impedance: 30/50 ohms for 12Z -2; 200/250 ohms for 12Z -3. (Continued next page) *dim, 1 mw into 600 ohms. The 12Z can be disassembled easily and completely, requiring only small hand tools. Unit construction has been used advantage ously for simplicity of maintenance. Page 9

115 12Z Remote Amplifier I. Output impedance: 600 ohms (150 ohms available on special order). Case: Welded aluminum alloy, finished in black wrinkle. Carrying case: Leather reinforced canvas. Microphone connections: Cannon type P supplied. Hubbell and other types available. ** Power source: 110 volts a -c or self- contained batteries. Batteries are low cost standard types, 3 Burgess M30 or Eveready 482, and 5 Burgess 4F or Eveready 742. Filament life is 50 hours. B Battery life is over 100 hours. Weight: With 3 45V B batteries and 5 A batteries approximately 40 lbs. 28 lbs without batteries. Size: 141" w, 111/2" h, 8t /q" d. Collins Part No.: Z Z -3 Tubes: Microphones, connecting wire, and small tools can be carried conveniently in a small brie! case or grip. **Refer to connectons, pages 39 and 40. MICROPHONE RECEPTACLES /50 OHMS 12Z-3 200/250 OHMS T TYPE LOW LOSS MIXING CONTROLS o oí - 3 STAGE AMPLIFIER CAM) INPUT - OUT PUT _I TRAIÖ J MASTER GAIN - AC POWER SUPPLY BATTERIES RELAY W TH AUTOMATIC CHANGEOVER PROGRAM MONITOR JACK METER SWITCH ISOLATION PAD OUTPUT OW TC VU METER /MULTIPLIER LINE MONITOR JACK LINE I LINE 2 TEL AC POWER 7Y4 RECEPTACLE Block diagram of Collins 12Z remote amplifier Page 10

116 ..212U Remote Amplifier. COLLINS, -- N., ---'\ COR MIXER. 212T /,REYOTEIYitlilF^ { L'l jv$s.-7 MICROPHONE POWER a 212U TWO -CHANNEL REMOTE AMPLIFIER The 212U consists of a type 60H mixer and a type 212Y amplifier. Both units are mounted in a single aluminum cabinet. A convenient carrying case is provided having a carrying handle and a shoulder strap. To set up this equipment the canvas carrying case may be removed, or, in bad weather, the front of the case may be opened by slide fastener for access to the controls. A snap fastened flap at the rear of the case allows connection of the microphones. The a -c cord provided is connected to the 212Y unit. If battery operation is required, a Collins type 412C -2 battery box and interconnecting cable must be used. The battery box is not included in the 212U equipment *. Line connections are made through binding posts on the 212Y unit. The mixing controls are ladder type attenuators, having db calibrations on the front panel. The master gain is the volume control on the 212Y. Legs raise the front of the unit to a convenient height for knob twisting and meter reading. The meter is a standard 3 inch vu meter with an adjustable range extension network. A phone jack on the 212Y panel allows headphone monitoring. The ease of operation and the very high fidelity and reliability of the 212U assure positive pick up of remote programs. SPECIFICATIONS Input impedance: 212U -I, 30/50 ohms. 212U -2, 150 ohms. 212U -3, 200/250 ohms. Output impedance: 600 ohms. Power output: +17 dbn: (1 milliwatt 600 ohms reference level). Distortion: Less than 11/2% between 50 and 15,000 cps. Noise level: Better than 65 db below program level. (Continued next page) (battery box). *Refer to page H Mixer 21W Aluminum Cabinet 212Y Remote Amplifier Page 11

117 . 212U 212Y Remote Amplifiers. (21211 continued from preceding page) Frequency response: ±2 db between 30 and 15,000 cps. Gain: 85 db less mixer insertion loss. Mixer insertion loss: Approximately: 212LT -1, 6 db. 212U -2, 10 db 212U -3, 4.5 db. Tubes: 2-6AQ6, 1-6AK6, 1-7Y4 Gain controls: Master gain, high resistance potentiometer. Mixers: Ladder type attenuators. Number of input channels: Two. Microphone receptacles: Cannon type XL -3-13; adapters available for other standard types. ** Finish: Black anodic aluminum panel, black wrinkle cover. Carrying case: Leather reinforced canvas with slide fastener and pouch for power and microphone cables, canvas carrying handle and shoulder strap. Size: 14" w, 6" h with legs (4%" less legs), 71/2" d. Weight: 13 lbs. Power source: 115 volts a -c 60 cps. Power supply is self- contained. Battery operation: Requires 412C -2 battery box* and interconnecting cable. Filament battery life approximately 50 hours. B battery life approximately 100 hours. Weight of battery box: Approximately 16 lbs., including batteries. Collins Part No.: 212U U U *Refer to page 15 (battery box). 4 *Refer to page 15 (adapters). MICROPHONE 212Y SINGLE CHANNEL REMOTE AMPLIFIER The Collins 212Y Remote Amplifier combines small size and light weight with high fidelity. Careful engineering design has produced an extremely compact, completely accessible unit suitable for dance orchestra and newsroom pickups. sports broadcasts, and any other applications where fast "set up" is important or necessary. The low cost of the 212Y further suggests its permanent installation at points where pickups are made regularly. The design of the 212Y includes all features necessary to provide dependable remote operation. Page 12

118 .212Y Remote Amplifier. One high fidelity channel is incorporated, which operates from a low level velocity, dynamic or other self -generating microphone. A universal input transformer matches all low impedance commercial type microphones. The 212Y Remote Amplifier is available in two models; the 212Y -1 which has a Cannon XL microphone connector, and the 212Y -2 which has a Cannon P3-13 microphone connector. Three stages of amplification provide an overall gain of 85 db, with an output of + 17 dbm *. A headphone jack connected across the output terminals permits program monitoring as well as talk -back from the studio. Because of its simple construction, installation, and operation, the Collins 212Y can be handled by nontechnical personnel without fear of program failure. The front of the leather reinforced carrying case, which has a pouch for power cord and microphone cable, opens by slide fastener to allow full access to all controls and connections. If desirable, the case may be removed completely. Line connections are made to binding posts, and the supplied a -c power cord is plugged into the front panel. If battery operation is required, the interconnecting cable from a 412C -2** battery box is connected. Merely exchanging plugs in the power input receptacle permita quick change from a -c to d -c operation. The battery box is not supplied with the 212Y. The amplifier slides into its case and is fastened by one Dzuz fastener. 212Y in Canvas Carrying Case The cover can be removed by loosening a single fastener. 212Y SPECIFICATIONS Size: 7" w, 4%" h, 61/4" d. Weight: 10 lbs. Number of channels: One. Gain: 85 db max. Input impedance: 30/50 ohms or 200/250 ohms. Output impedance: 600 ohms. Power output: +17 dbm". Distortion: Less than 1.0% between 30-15,000 cps. Noise level: 65 db below normal program level. Tubes: 2 6AQ6, 1 6AK6, 1 7Y4. Frequency response: Within 1.0 db; 30-15,000 cps. Gain control: High resistance potentiometer. Microphone receptacle: 212Y -1- Cannon type XL (Adapters available for other standard types.) ** 212Y -2- Cannon type P3-13. Finish: Black anodic aluminum panel, black wrinkle cover. Carrying case: Leather reinforced canvas with pouch for power and microphone cables. Power source: 115 volts a -c, 50/60 cps. Power supply is self -contained. Battery operation: Requires battery box and interconnecting cable. ** Weight of battery box: Approx. 16 pounds including batteries. Collins l'art No.: 212Y Y milliwatt. 600 ohm base. "See Page 15. Page 13

119 .. 60H Remote Mixer 60H TWO -CHANNEL REMOTE MIXER The Collins 60H Mixer is a two -position, low-level mixer to be used in conjunction with the Collins 212Y Remote Amplifier. It consists of a mixer chassis in a cabinet which has an opening for the insertion of the 212Y Amplifier, and a convenient canvas carrying case with both a carrying handle and a shoulder strap. The 212Y slides into the 6011 mixer case exactly as it does into its own case. A built -in plug and socket arrangement handles the interconnection problem at the same time the amplifier is installed in the mixer case. A standard 3 -inch vu meter with adjustable range extension attenuator is provided for visual monitoring of the program material, while headphone monitoring is accomplished as before in the 212Y amplifier. The two ladder type attenuators are furnished with convenient control knobs having decibels calibration on the front panel. The volume control on the 212Y will then serve as a master volume control. The mixer rests upon two removable legs which raise the knobs to a convenient height and tilt the panel at an angle to afford sight of the dial calibrations and meter scale. The microphone connections are at the rear of the cabinet. The canvas carrying case is equipped with two snap fasteners to hold the case on the mixer when operating in inclement weather. A flap on the rear of the case opens to allow insertion of the microphone connectors and at the same time protects them from the weather. 60H SPECIFICATIONS Input impedance: , 30/50 ohms. 60H -3, 150 ohms. 60H -4, 200/250 ohms. Output impedance: 60H -2, 50 ohms. 60H -3, 250 ohms. 60H4, 250 ohms. Insertion loss: 60H -2, 6 db. 60H -3, 10 db. 60H -4, 4.5 db. Gain controls: Ladder type attenuators, step by step. Number of input channels: Two. Microphone receptacle: Cannon type XL Adapters are available for other standard types. * Finish: Black anodic aluminum panel, black wrinkle cover to match 212Y. Dimensions: 14" w, 6" h with legs (4%" h less legs), 71/2" d. Carrying case: Leather reinforced canvas with slide fastener and pouch for power and microphone cables; canvas carrying handle and shoulder strap. Weight: Mixer and carrying case only, 6 pounds. Collins Part No.: H H *See Page 15. Page 14

120 412C Battery Box. Adapters -412C BATTERY BOX The 412C-2 battery box is sturdily constructed, and holds the batteries securely. There is room in the top of the case for storing the 6 ft. rubber jacketed cable for transportation. Three thumb screws hold the clamp which secures all of the batteries in place. A convenient carrying handle is provided. Finish: Black wrinkle. Dimensions: 103/4" w, 6%" d, 93/4" h. Weight: With batteries approximately 22 lbs. Collins Part No.: (less batteries). Collins Part No. of Battery Kit: Requires standard low cost type batteries: 4- Burgess M30 or Eveready 482 or equivalent. Collins Part No Burgess 4F or Eveready 742 batteries, or equivalent. Collins Part No MICROPHONE ADAPTERS i I 65S -5 WITH HUBBELL S -6 WITH HUBBELL WITH HUBBELL WITH HUBBELL WITH CANNON P3- CG -11$ Adapters using other type connectors available on special order. Page 1.5

121 Rack Mounted Speech Equipment. Introduction On the following pages the complete line of Collins standard rack mounted speech equipment is shown and described, including: Amplifiers Power Supplies Metering Panels Jack Panels and Accessories Equalizers Repeat Coils and Panels Mixer and Attenuator Panels Racks and Accessories These units are designed for mounting in standard 19 inch racks, and every effort has been made to provide ready accessibility for adjustments and maintenance without removal from cabinets. Page 16

122 s 6P-1 Preamplifier. n 6P -1 PREAMPLIFIER The Collins 6P is a high fidelity preamplifier designed for service in AM, FM and TV applications. It operates from a low -level microphone or similar source and has sufficient output to drive a program amplifier, or audition facilities. As many as five of these preampliers, which require an external power supply, can be powered from the Collins 409T -3 power supply. The 6P uses standard tubes and has two stages of amplification. It is carefully engineered for high performance through the use of the latest circuit refinements and improved components. Generous safety factors throughout insure operating reliability. The hum and noise levels are low, and the output is clean and brilliant. The frequency response is flat from 30-15,000 cps, with a variation of only ±1.0 db. Distortion at normal program level is less than 1.0 %. Adequate shielding and careful circuit arrangement prevent cross- modulation between preamplifiers when more than one are used, even when they are placed side by side. Two gain positions are provided, giving approximately 45 db or 35 db amplification respectively. Gain is constant for a given setting. The advanced design of the 6P provides easy accessibility to all parts. An access door in the panel permits tube changing from the front. Removal of the slip -on dust cover gives immediate access to all circuit components. Input impedance: 30/50, 200/250, or 500/600 ohms. Output impedance: 600 ohms (150 ohms available). Input level: Commercial microphone level. Output level: -35 to -15 dbm *. Overall gain: 45 db in high position, 35 db in low position. Frequency response: 30-15,000 cps ±1.0 db. Noise level: -65 db from program level. Distortion: Less than 1.0% at program level. Tube complement: or 2-6J7. Power requirements: 6.3 volts a 0.6 amperes, 180 volts 6 ma. Use Collins 409T -1 or 409T -3 power supplies. Mounting: Standard 19" rack. Mounting dimensions: 19" w, 31/2" ly 71/2" d. Finish: Metallic gray. Weight: 11 pounds. Collins Part No.: I milliwatt, 600 ohm base. Rear view with dust cover removed. Page 17

123 Amplifiers a a 6R -2 ISOLATION AMPLIFIER The 6R -2 is a two stage push -pull amplifier. The gain control has twenty steps of 2 db each, and is located immediately behind the access door. Tubes are easily accessible through a door in the front panel. Other components are easily reached by removing the dust cover, held in place by spring fasteners. Provisions have been made for external metering of the tube currents. Frequency response: 30-15,000 cps ±1.0 db. Distortion: 1% max. at any level up to +20 dbm. Noise: 65 db. Overall gain: +45 db as line amplifier, +35 db as bridging amplifier. Gain control: step by step with detent, 2 db per step. Output level: 20 to +20 dbm. Maximum input level: 10 dbm. Input impedance: 600 ohms, or bridge with 20,000 ohms. 150 ohms available. Output impedance: 600 ohms, 150 ohms available. Tube complement: 2-6SN7. Power requirements: 6.3 volts Cu 0.6 amp. a -c or d -c. 100 to 250 volts d -c at 20 ma. Power may be obtained from the Collins 409T -1 or 409T -3 power supplies. Dimensions: 19" w, 3%" h, 81" d. Finish: Metallic gray. Weight: 10% pounds. Collins Part No.: dbm, 1 mw into 600 ohms. 6T MONITOR AMPLIFIER The 6T is a 2 watt monitor amplifier having a self -contained power supply. The power switch, pilot light, and volume control are mounted on the front panel, tubes are accessible from the rear. Input impedance: 600 ohms matching, or 20,000 bridging. Output impedance: 600, 150, 16, 8, and 4 ohms. Frequency response: ,000 cps +2 db. Gain: 55 db. Matching 600 ohms. 45 db. Bridging with 20,000 ohms. Distortion: Less than 3%. Noise: 65 db. Output level: +33 dbm *. Maximum input level: +10 dbm'. Tubes: 2-12AU7, 2.6AQ5, 2-6X4. Finish: Metallic gray. Mounting dimensions: 51/2" It, 19" w, 61/2" d. Power requirements: 115 volts a -c, 50/60 cps. Weight: Approx. 15 pounds. Collins Part No.: 'dbm, 1 mw into 600 ohms. Page 18

124 Amplifiers. 6X -2 MONITOR AMPLIFIER The Collins 6X -2 is a reliable 10 watt monitor amplifier complete with self -contained power supply. Its high fidelity, typical of all Collins speech equipment, commends its use for AM, FM and TV broadcasting and in the most exacting professional recording work. All tubes are easily reached through the door in the front of the unit. Other components are made readily available by removal of the slip -on dust cover. Because of its excellent electrical characteristics, its 10 watts of audio power, and its inbuilt power supply, the 6X -2 is also an unsurpassed amplifier to follow a good AM -FM tuner and to be followed by a high fidelity speaker, for custom installation in schools, clubs, homes, and other applications calling for the finest radio reception. SPECIFICATIONS Number of channels: One. Input impedance: 600 ohms matching, 20,000 ohms bridging (150 ohms available). Output impedance: 600 ohms, balanced. Output level: +40 dbm (10 watts, 12 watts max.). Overall gain: 55 db maximum. Frequency response: 30 to 15,000 cps ±1.5 db. Noise level: Better than 70 db below output level. Distortion: Less than 2% from 50 to 15,000 cps, 10 watts output. Tubes: 1.6SN7, 1.6SL7, 2.6L6G's, 1.5V4G. Power source: 115 volts a -c, 50/60 cps. Mounting dimensions: 83/" h, 19" w, 10%" d. Weight: 34 pounds, 10 ounces. Finish: Metallic gray. Collins Part No.: Tubes: Page 19

125 26W -1 Limiting Amplifier 26W -1 LIMITING AMPLIFIER The 26W -1 limiting amplifier is recommended for use in any AM or FM installation where it is desired to control the amplitude of audio frequency peaks. In AM transmitter applications it limits loud audio passages, thus preventing overmodulation and the accompanying distortion and adjacent channel interference. This limiting action permits a higher average modulation level, and, consequently, a stronger transmitted signal. In FM applications the 26W -1 limiter is necessary to prevent excessive transmitter swing which, in general produces distortion at the receiver due to the inability of the average discriminator to handle frequency swings greater than 150 kc. In FM systems the use of wide range reproducer systems makes such distortion extremely noticeable. The 26W -1 performs with equal satisfaction in recording equipment and high quality P.A. systems. It regulates the audio level and prevents overloading the cutting head or speaker, and by raising the average audio level it improves signal to noise ratio. The 26W -1 amply meets the three most important requirements of a superior product -(1) performance to comply with the specifications prescribed by the application, (2) reliability of operation, and (3) accessibility for maintenance. Thorough consideration was given the resistance- capacitance circuits and transformers to produce a true high fidelity frequency response. Distortion and noise are extremely low. Input and output levels are adjustable. Two high quality meters provide a continuous visual indication of operating conditions. Individual tube operation, supply voltage, the amount of compression in db, and the output in vu are metered. The limiter stage can be adjusted easily from the front to precise balance, which makes it a simple job to hold the distortion to a very low level. A door in the front panel provides access to all Page 20

126 . 26W -1 Limiting Amplifier. tubes. The dust cover is fastened by snap fasteners, and requires no tools for removal. The inside -out chassis construction reaches a new standard for accessibility of components; all resistors and circuit capacitors are on the rear of the chassis and are outermost upon removal of the dust cover. The very best components, conservatively operated, are employed in the 26W -1. Electrolytic capicators appear only where specified performance cannot be obtained with paper capacitors, and are limited to cathode circuits with less than 50 volts potential. Transformers are sealed, and all insulating materials are the best available. Frequency range: 50-15,000 cps ±1.0 db. Input impedance: 200, 600 ohms, or bridging. Input level: -25 to +25 dbm *. Output impedance: 600 ohms. Output level: -12 to +18 dbm *. Gain controls: Input and output levels adjustable in 30 steps of 1 db. Overall gain: 47 db max. Compression ratio: 18/1 in db above verge of compression. Operate time: Adjustable 1.0, 3.0, or 10.0 milliseconds. Release time: 1.0, 2.5, or 5.0 seconds. Distortion: Harmonic distortion below 1% rms at any frequency from 100 to 15,000 cycles with no compression. 50 cycle distortion below 1.5% under sanie conditions. Harmonic distortion below 2% from 100 to 15,000 cycles at any value of compression up to 10 db. Hum and noise: -65 db below output level. Controls: Input and output attenuators, vu range switch, and meter selector switch. Metering circuits: Individual tube currents, plate voltage, compression level, and output level. Tube complement: 3-6N7, 1-6H6, (2-6F6 may be used), 1.5V4G. Power source: 115 volts a -c, 50/60 cps. Dimensions: 14" h, 19" w, 9" d, for rack mounting. Weight: 45 lbs. (55 lbs. shipping weight). Finish: Metallic gray panel. Collins Part No.: Tubes: dbm, 1 mw into 600 ohms. Page 21

127 . Console Type Amplifiers o(i-1 117P -1. 6N 6S-2 ; l' 6W T.2 CONSOLE TYPE AMPLIFIERS Heretofore employed primarily in custom installations, the fine amplifiers used in the Collins 212 series consoles are now available for mounting in other equipment. Shown above and described on this and the following pages are: 6Q Dual Preamplifier 6N Program Amplifier 6S -2 Two -stage Isolation Amplifier 6V 10 -Watt Monitor Amplifier 6W Watt Monitor Amplifier 117P -1 Repeat Coil Unit 409T -2 Power Supply for 6N, 6S or 6W -2 The 409T -2 power supply is capable of operating two 6N program amplifiers, five 6S -2 isolation amplifiers, or two 6W watt monitor amplifiers. Power for the 6Q dual preamplifiers may be obtained from a 409T -3 power supply, a standard rack mounting unit listed elsewhere in this section. The 409U -1 or -2 power supply, as supplied with the 212 series consoles, is recommended for use with these amplifiers if a complete system is contemplated. See listing of 409U -1 or -2 on page 6 of CONSOLES section. 6Q -1 DUAL PREAMPLIFIER The 6Q contains two preamplifiers on one chassis. These amplifiers usually work into a program amplifier, such as Collins 6N or 6R. An external power supply is needed. Input impedance: 50 or 250 ohms. Input level: Commercial microphone level. Output impedance: 600 ohms. Gain: 47 db. Frequency response: ±1 db ,000 cps. Distortion: Less than 1 %. Noise: Better than 65 db. Tubes: 2-6AQ6, 2-6C4. Power requirements: 140 volts d 8 ma. 6.3 volts a -c or d 0.6 amp. Dimensions: 43/4" h, 41/2" w, 10%" d. Weight: 5 pounds 2 ounces. Collins Part No.: Tubes: N -1 PROGRAM AMPLIFIER The 6N is a program amplifier meeting the strictest requirements of present day broadcasting -AM, FM, or Television. Mounted on a console type chassis, it requires an external power supply. A dual section, 100,000 ohm -per-section potentiometer is also required, such as the Collins No Input impedance: 600 ohms matching or 20,000 ohms bridging. 150 ohms available. Input level: Not exceeding 10 dbm ". Output level: +30 dbm*. Output impedance: 600 ohms. 150 ohms available. Gain: 68 db matching. 58 db bridging. Frequency response: ±-1 db 30-15,000 cps. Distortion: Less than 1% at +30 dbm *. Noise: Better than 65 db. Tubes: 2-6AQ6, 2-6C4, 2-6F6. Power requirements: 325 volts d 50 nia. 6.3 volts a -c or d 2 amp. Dimensions: 53/" h, 6" w, 101/2"d. Weight: 4 pounds, 12 ounces. Collins Part No.: Tubes: *dam: reference level I mw, 600 ohms. Page 22

128 Console Type Amplifiers a 6S -2 ISOLATION AMPLIFIER The 6S -2 is a two stage push -pull isolation amplifier. It may be used as a bridging amplifier for monitoring, as a distribution and isolation amplifier, as a program booster at studio or transmitter, or as a program amplifier. An external power supply is required. The components are mounted on a console type chassis, and are all easily accessible. A screwdriver operated switch will vary the gain in four steps of 3 db per step. Frequency response: 30-15,000 cps -}1.0 db. Distortion: Less than 1% at any level up to +20 dbm* output. Noise: 65 db. Overall gain: +45 db line matching, +35 db bridging. Input level: 10 dbm* max. Output level: 20 to +20 dbm*. Input impedance: 600 ohms, or bridge with 20,000 ohms, 150 ohms available. Output impedance: 600 ohms, 150 ohms available. Tube complement: 2-6SN7. Power requirements: amp a -c or d -c. 100 to 250 volts d -c at 20 ma. Dimensions: 51/2" h, 41/2" w, 101/2" d. Weight: 5 lbs., 4 oz. Collins Part No.: "dbm: reference level 1 mw, 600 ohms. 6V -2 MONITOR AMPLIFIER The 6V -2 is a 10 watt monitor amplifier mounted on a console type chassis. A dual section (25,000 ohm per -section) potentiometer is needed, such as Collins No no detent; or Collins No with detente. This amplifier may be used on a 600 ohm circuit, matching, with 62 db gain, or as a bridging amplifier with approximately 52 db gain. An external power supply is needed. Input impedance: 600 ohms matching, or 20,000 ohms bridging. Input level: Not more than 10 dbm*. Output impedance: 600 ohms balanced. Gain: 62 db matching 600 ohms. 52 db bridging with 20,000 ohms. Frequency response: ±1 db 30-15,000 cps. Distortion: Less than 1% at +40 dbm (vu). Noise: Better than 75 db. Power requirements: 325 volts d 150 ma. 6.3 volts a-c or d 2.7 amp. Dimensions: 61/2" h, 6" w, 101 /2" d. Tube complement: 6SN7, 6SL7, 2-6L6. Weight: 7 pounds. Collins Part No.: Tubes: "dbm: reference level I mw, 600 ohms. 6W -2 MONITOR AMPLIFIER The 6W is a 2 watt amplifier mounted on a console type chassis. It may be used to drive monitor speakers, or for any other applications requiring up to 2 watts. An external power supply is needed. A screwdriver operated switch will vary the output level in 4 steps of approximately 3 db each. Input impedance: 600 ohms. 150 ohms available. Input level: Not over 10 dbm. Output impedance: 600 ohms. 150 ohms available. Gain: 45 db, 600 ohms matching, 33 db at 20,000 ohm bridging. Frequency response: 30 to 15,000 cps ±1.5 db. Distortion: At +30 dbm, less than 1%. Noise: Better than 70 db from +30 dbm* output. Power requirements: 325 volts d 50 ma. 6.3 volts a -c or d 1.7 amp. Dimensions: 51/2" h, 41/2" w, 102" d. Tube complement: 6SL7, 2-6F6 or Weight: 4 pounds, 12 ounces. Collins Part No.: Tubes: *dbm: reference level I mw, 600 ohms. Page 23

129 Power Supplies 117P -1 REPEAT COIL UNIT The 117P -1 consists of two coils mounted on a console type chassis. The characteristics of the repeat coils are as follows: Input impedance: 600, 250 or 50 ohms balanced. 150 ohms available. Input level: +25 dbm* max. Output impedance: 600 ohms. 150 ohms available. Distortion: Less than 0.2% at +25 dbm*. Frequency response: ±0.4 db 30-15,000 cps. Dimensions: Vie h, 41/2" w, 101/2" d. Weight: 1 pound, 14 ounces. Collins Part No.: dbm: reference level 1 mw, 600 ohms. low bum level. Both plate supply and filament power are available, with a tapped primary for voltage adjustment. Collins 6P preamplifiers and 6R isolation amplifiers may be mounted in the same rack with the 409T -1 power supply, and fed directly from it. Tubes: 2-6X5. Plate supply voltage: 250 volts d Filament supply voltage: 6.3 volts a -c Dimensions: 19" w, 51/4" li, 71/2" d. Weight: 24% pounds. Finish: cover. Collins Part No.: Metallic gray panel, velvet a. gray dust 409T -2 POWER SUPPLY A power supply mounted on a console type chassis, 11/2" wide. Mounting holes are standard for mounting in Collins consoles. By changing 2 resistors supplied in a kit, any one of the voltages and currents listed below may be obtained. 325 volts d 50 ma. 300 volts d 100 ma. 250 volts d 50 ma. 250 volts d 75 ma. 250 volts d 100 ma. Also 6.3 volts a 5 amp, Cr Tube: 5R4GY. Output connections: Solder type terminals. Input: 115 volts a-c 50/60 cps. Dimensions: 81/2" h, 41/2" w, 101/2 "d. Weight: 8 pounds, 4 ounces. Collins Part No.: T -1 POWER SUPPLY 409T -I Power Supply A rugged, reliable power supply is a necessity for innumerable applications. The 409T -1 is a well engineered unit, with sturdy components and a very 409T -3 POWER SUPPLY 409T.3 Power Supply The 409T -3 is a rack mounting power supply on a 31/2" panel. The power switch and pilot light are on the front panel. Connections to the unit are made to a covered terminal board at the rear. Any one of the output voltages and currents listed below is made available by changing two resistors supplied in a kit. Two plug-in high capacity electrolytic condensers of ample safety margin contribute to an extremely well filtered output. The filter input capacitor is an oil - filled paper unit. Ripple voltage:.005 volts at 250 volts d -c, 50 ma. Output: 325 volts d 50 ma. 250 volts d 50 ma. 180 volts d 50 nia. 140 volts d 50 ma. 250 volts d 25 ma. 140 volts d 20 Ina. 6.3 volts a 3 amp. Tubes: 1-6X5. Finish: Metallic gray. Weight: 11 pounds. Input: 115 volts a -c 50/60 cps. Collins Part No.: Page 24

130 Relay Power Supply, vu Panel. Input: volts a -c. 50/60 cps. Output: 12 volts d -c at 5 amperes volts a-c center tapped at 5 amperes. Collins Part No.: F -4 RELAY POWER SUPPLY 409T -3 Power Supply (rear view) 409U -1 & 2 POWER SUPPLY (see page 6) 414F -3 RELAY POWER SUPPLY A well filtered, well regulated, dependable d -c power source for operating relays and pilot lights. The power transformer has a tapped input permitting operation on line voltages from 105 to 125 volts. A rugged selenium rectifier followed by a filter network furnishes the d -c power suitable for use in control circuits run g near the lower level audio circuits. The 414F -4 Relay Pow er Supply is designed for use where a small number of relays are to be operated. This unit provides a source of 12 volts d -c at 1 ampere, and 12.6 volts a -c center tapped, at 3.5 amperes. Where low current drain is feasible for operating relays, the small size of the 414F -4 makes it especially desirable. The 12.6 volt a -c center tapped voltage is also useful for a filament supply or for operating pilot lamps. Power source: 115 volts a -c, 50/60 cps. Output voltage: 12 volts d 1 amp volts a -c 3.5 amps. Dimensions: 19" w, 31/z" h, 7" d. Weight: 8% pounds. Finish: Metallic gray. Collins Part No.: E vu PANEL Open view of 414F-3 The 414F -3 is placed in a wall mounting cabinet and is accessible through a hinged access door on the front. An on -off switch and a pilot light are mounted on the front of the cabinet. A fuse receptacle is available through the access door. Dimensions: 20%" w, 11" h, 10" d. Weight: 35 pounds. Finish: Metallic gray door, glossy black cabinet. The 62E is designed for accurate monitoring of audio levels in broadcasting, recording studios, and sound systems. A Weston type 30 meter is provided, with illuminated face and easily read figures. Over - swing is small, and pointer action is deliberate and positive. The 62E -1 meter has a type A scale, with -20 to +3 vu on the upper side and zero to 100% on the lower side. The 62E -2 meter has a type B scale, with per cent calibrations on the upper side. (Continued next page) Page 2.5

131 Meter Panel Metering Unit. Three controls are provided. Any of four circuits can be monitored by means of the circuit selector switch. The attenuator control is calibrated at 1 milliwatt (zero level) and in steps of 2 db up to a total of 40 db. In addition, a vernier screw adjustment allows ±0.5 db variation for coordinating various meters. The 62E vu panels are designed to operate from a 600 ohm line. However, other impedances may be used in conjunction with a calibration chart. Input impedance: 7500 ohms constant except on the 1 mw calibration position. Attenuator range: +4 db to +40 db in 2 db steps. T -type construction. Number of input circuits: Four. Meter scale: Standard vu. 62E -1: Type A Scale. 62E -2: Type B Scale. Frequency range: Constant response within 0.2 db up to 10,000 cps. Power requirement for meter illumination: 6.3 volts a -c or 0.3 amp. Dimensions: 19" wide for standard rack mounting, 51/4" high. Finish: Metallic gray. Weight: 9 pounds. Collins Part No.: 62E E METER PANEL TYPE 82D -7 Dimensions: 19" w, 51/4" h, 5" d. Finish: Metallic gray. Weight: 6 pounds. Collins Part No.: 82T -1 METERING UNIT (less meters). The 82T -1 is a versatile unit for measuring currents of various rack mounting type amplifiers, such as the Collins 6X, 6P, and 6R and the console mounting type amplifiers, such as 6Q, 6N, 6V, 6S, and 6W. It is also adaptable for use with any circuit employing tapped cathode resistors of the proper multiplier values, or in circuits where the multiplier is in the plate circuit. The unit is wired to accommodate 10 plate metering circuits, and 10 cathode metering circuits. By adding jumpers on the terminal strip, the unit will operate for 20 cathode circuit measurements. The basic meter movement is 1 ma full scale, and is calibrated 0 to 5. It will indicate currents of 0-5, 0-50, and ma with a 25 ohm, 2.04 ohm or 0.22 ohm multiplier resistor. In addition to the direct current measurements, a twenty -first position allows a check of the a -c voltage in the rack. The dust cover protects switches and is held on by means of two snap fasteners. Meter panels have many applications in monitoring and measuring equipment. D -c and a -c voltages and currents can be continually metered by using this convenient rack mounting panel. The unit accommodates four meters of the Weston type 301 size (not supplied), and is equipped with a dust cover 71/2" deep. Dzus fasteners are employed to bold the cover in place. The panel is made of aluminum, %a" thick. Meters are available to suit any requirements. Dimensions: 12" w, 51/4" h, 71/2" d. Weight: 10 lbs. Finish: Metallic gray. Current range: 0-5, 50, 500 ma (with appropriate circuit). a -c Metering: Indicates 120 volts center scale, and shows variations of 5 volts per 1 scale division from 80 to 130 volts. (Scale not calibrated for a -c volts). Collins Part No.: Page 26

132 . Jack Panel. TYPE 265D JACK PANELS Utmost flexibility is afforded a control room through the use of jack strips and associated patch cords. Connections can be made for test purposes or for terminating program lines and order wires. Lines, amplifiers, microphones, equalizers, and other audio equipment can be speedily interchanged for maintenance or emergency operation. These jack panels mount in standard 19 inch racks. Regularly supplied with Collins jack. Type No. Description Height Weight Part No. 265D pr. jacks 1%" 31/4 lbs D pr. jacks 31/2" 61/2 lbs D pr. jacks 51/4" 111/2 lbs D pr. jacks 7 " 17 lbs D pr. jacks 101/2" 22% lbs D pr. jacks 121/4" 28 lbs LONG FRAME TWO CIRCUIT JACKS Circuit Part Number Break one, make one Break one Make before break PATCH CORDS Patch cords for use with jack strips are available in lengths from 6 inches to 10 ft. The plugs are of the shielded type, with the sleeves tied together and grounded. The circuit is maintained through connections to the plug tips. Length Part No. 2ft ft ft ft ft ft ft Male, three conductor patch plug V 360 o i o v o o o t o o o o o Jack circuit schematic Page 27

133 Program Equalizers EQUALIZATION LOW FREOU' EQUALIZATION NICK FREQUENCY EQUALIZATION PROGRAM EQUALIZERS Collins Equalizers provide complete facilities for controlling the frequency response of program and communication circuits. The circuit is new and ingenious, giving simple, smooth control of equalization. As these units have an insertion loss of approximately 30 db, the Collins 6R Isolation Amplifier used in conjunction with the equalizers will provide a means of bringing the level back to normal, phis a little gain if desired. 116F -1 EQUALIZER Input and output impedance: 600 ohms, unbalanced. Equalization frequencies: 30, 50, 100, or 200 cps at low frequency. 5, 7, 10, or 15 kc at high frequency. Maximum boost: 26 db, in steps of 2 db each High and low frequency equalization indepen dently adjustable. Insertion loss: 30 db at unequalized frequency. Frequency range: 30-15,000 cps. Dimensions: 19" w, 51/4" h, 71/2" d. Weight: 15 pounds. Finish: Metallic gray. Collins Part No.: fiíri tü NW * 116E -1 performance curves. y. e:p- o- -- 'wr Mat g444i!l IIIlNR:O1gai - 88!. _i!i GE.Ii=o1ll---' _CÌlI-:::_ =NENREIilliiO1i1;áels: o IS I : :mom9si - ---_.! -1-,_..,. S., IS, n1011-kt C.C-,,..KO.,..., Page 28

134 Program Equalizers 116E -3 AND 116E -4 EQUALIZERS The 116E -3 and -4 equalizers are another application of the 116F -1 circuit with a variable insertion loss dependent upon the amount of equalization used. Especially s uited for stations having a variety of remote programs coming from different lines, the 116E -3 and -4 offer equalization in the high frequency ranges only. A calibrated attenuator selects the amount of equalization at the required frequency which is selected by a panel switch. Such calibration reduces line equalization time to a single run to find the line characteristics, and adjustment of the equalizer to the conjugate frequency characteristic. The 116E -3 is a single high frequency equalizer while the 116E -1 has two identical high frequency equalizers mounted on the sanie panel with separate input and output terminals. Both are supplied with a flat gray finished dust cover. 116E -3 EQUALIZER Input and output impedance: 600 ollnls unbalanced. Equalization frequencies: 5, 7, 10, and 15 kc. Maximum boost: Approx. 30 db. Insertion loss: Approx. equal to amount of equalization used. Frequency range: 30 to 15,000 cps. Dimensions: 19" w, 31/2" h, 71/4" d. Weight: 6 pounds, 7 ounces. Finish: Metallic gray panel; flat gray back. Collins Part No.: E -4 EQUALIZER Input and output impedance:600 ohms unbalanced. Equalization frequencies: 5, 7, 10, and 15 kc. Maximum boost: Approx. 30 db each channel. Insertion loss: Approx, equal to amount of equalization used. Frequency range: 30 to 15,000 cps. Dimensions: 19" w, 31/2" lt, 81/4" d. Weight: 9 pounds, 7 ounces. Finish: Metallic gray. Collins Part No.: c. s , EREOUENCY CYCLES RER 1000 SECOND I! 2 i S 1 I I R :0D Page 29

135 Repeat Coil Panels,, Allentuator Panels 117N -2 REPEAT COIL PANEL REPEAT COILS -THORDARSON R-4 CASE The 117N -2 Repeat Coil Panel is a complete assembly including chassis, terminal board, and dust cover, but less repeat coils. This unit will accommodate four Thordarson type repeat coils with an R -4 case. There arc 50 terminals on the board for making connections to external equipment. The dust cover is held on by two convenient Dzus fasteners. Dimensions: 5%" h, 19" w, 5" d. Weight: 71/2 pounds (less coils). Finish: Metallic gray panel, velvet gray dust cover. Collins Part No.: (less coils). 1. Line to Line No Primary Secondary 2. Line to Mult. Line Primary No Secondary 1 Secondary 2 Secondary 3 3. Line to Mult. Line Primary No Secondary 1 Secondary 2 4. Bridging Primary No Secondary 5. Line to Mult. Line Primary No Secondary 1 Secondary ohms 250 ohms 50 ohms, split 600 ohms, split 600 ohms, split 600 ohms 600 ohms 600 olntis 600 ohms, split 600 ohms, split 600 ohms, split 20,000 ohms. split 600 ohms 250 olrnts 50 ohms, split 600 ohms, split 250 ohms, split 50 ohms, split 268A- 1/268B -1 ATTENUATOR PANELS Separate gain control may be maintained over incoming and outgoing lines, auxiliary amplifiers, and speakers, by the use of the Collins 268A -1 and 268B -1 attenuator panels. The 268A -1 consists of two balanced ladder attenuators while the 268B -1 features two bridged -tee type attenuators. Both attenuator types have 20 steps, 2 db attenuation per step, with infinite attenuation in the last step. Connections are conveniently brought out to a terminal strip on the rear. The front panel is attractively engraved to indicate decibels of attenuation. Dimensions: 31/2" h. 19" w, 4" d. Input or output impedance: 600 ohms. Other impedances available. Finish: Weight: Metallic gray. 268A -1, 8 pounds, 14 ounces. 268B -1, 8 pounds, 14 ounces. Collins Part No.: 268A B Page 30

136 e. e T.1rtIrt1 l 51 K Terminal Boards a a! 1rtrif{rti The 151K -6 is similar to the 151K -1 except that 144 telephone type terminals are provided as well as the 60 heavy duty terminals. Part No Wt. 3 lbs. The 151K -1 terminal board 151K TERMINAL BOARDS 151K -1. (above) is used in the base of rack mounting cabinets. It contains 96 telephone type solder terminals for audio connections, and 60 heavy duty threaded stud type terminals for power connections. Part No Wt. 2 lb., 14 oz. The 151K -5 is a terminal board consisting of 100 telephone type terminals, 25 in a row, 4 rows deep, on a 31/2" x 8" bakelite board which has 71/2" x 21/2" mounting centers. Part No Wt. 1 lb. The 151K -4 has 4-151K -5's assembled on an inclined plane on an 83/4" x 19" panel, for standard rack mounting. The assembly is 71/2" deep. Part No Wt. 7 lbs. The 151K -3 is identical to the 151K -4 except it has only 3-151K -5's assembled on a panel. Part No Wt. 8 lbs. 151K -5 terminal assembly The 151K -3 terminal assembly Page 31

137 .,.. Warning Light assemblies. ON THE AIR STAND BY ON THE AIR STAND BY 209A A A WARNING LIGHT ASSEMBLIES The type 209A Studio Warning Lights are con- SPECIFICATIONS: structed of aluminum sheet metal with a divided light compartment. Each of the two light compart- 209A -1 -For mounting flush with the wall. Sign ments contains two 71/2 watt 110 volt a -c bulbs and must be ordered separately. sockets to provide illumination of the lettering. Dimensions: 4%" h, 7%" w, 2" d. The 209A -1 flush type is mounted with the light box recessed in the wall, using the light box as the Weight: 11 oz. junction box, or mounting it to a standard junction Collins Part No.: box recessed deeper into the wall. The cover plate mounts directly to the wall with four screws. 209A -2-For wall mounting. Sign must be ordered separately. The 209A -2 external type is mounted with the light box directly over a standard junction box which is Dimensions: 4 i 6" h, 91/2" w, 2" d. recessed in the wall the usual depth. The cover Weight: 15 oz. plate mounts directly to the light box with two screws. Collins Part No.: SIGNS The signs are made of boilable lucite with a black surface except for colored lettering.* The weight of each sign is 2 oz. The four available signs are: ON THE AIR Red letters STAND BY Green letters Part No ON THE AIR Red letters AUDITION Green letters Part No ON THE AIR Red letters REHEARSAL Green letters Part No AM Red letters FM Green letters Part No *Special wording available at additional cost. Page 32

138 112B -1 Switch and ruse Panel, 112B -1 SWITCH AND FUSE PANEL The 112B -1 provides primary a -c control over ten different circuits. A heavy -duty circuit breaker, operated by a snap action switch, carries the total a -c load, and each of the ten circuits is individually fused. A terminal board and (lust cover complete the unit. A door in the front panel furnishes convenient access to the fuses. The panel is 51/4" high, and mounts in a standard 19" rack. Metallic gray finish. Weight, 61/2 pounds. Complete with set of extra circuit breaker heaters for operation at 3, 5 or 7 amperes. Furnished with 9 ampere link installed. Rear view, dart cover removed Collins Part No.: amp replacement link amp replacement link amp replacement link amp replacement link SHIELDED RADIO HOOKUP WIRE Two Conductor: Two insulated conductors, twisted and covered by tinned copper braid. Each conductor: No. 20AWG gauge, 3 amp capacity. Two solid colors, or solid color with tracers to distinguish one conductor from another. Shielding: 96 strands No. 34AWG tinned copper wire braided in groups of 4 strands side by side. Collins Part No.: Solid conductor Fiber glass braid insulation Solid conductor Lacquered cotton braid insulation Same as except cotton braid overall strands min. Fiber glass braid insulation strands min. Lacquered cotton braid insulation Same as except cotton braid overall. Two Conductor: Each conductor color coded, No. 16AWG (19 strands min.) 15 amp a -c, 1000 volts rms. Lacquered cotton braid insulation. Shield: 90 (min.) strands of No. 32 to No. 38AWG tinned copper wire with 5 (min.) strands running side by side. Overall di am.: 0.32" max. Collins Part No.: Two Conductor: Each conductor No. 12AWG (19 strands min.) 20 amp a -c, 1000 volts rms. Lacquered cotton braid insulation color coded. Shield: 92 strands of No. 34AWG tinned copper wire with 4 strands side by side. Overall diameter: 0.420" max. Collins Part No.: Microphone Cable (Rubber) : Two insulated conductors, twisted, covered by tinned copper shielding and encased in rubber. Diam. approx ". Each conductor: 26 strands No. 34AWG tinned soft annealed wire twisted for flexibility. Equiva- lent to No. 20AWG gauge 3 amp 300 volts. Rubber covering %.4 ", one white, one black. Shield: 96 strands of No. 34AWG tinned copper wire, braided with 4 strands running side by side. Jacket: %.t" black rubber. Collins Part No.: Page 33

139 Test Equipment r General Radio Type A AM Modulation Monitor General Radio Type A Audio Oscillator The importance of test equipment in the maintenance of your station cannot be overstressed. Test equipment, properly used, tells your engineer what operating conditions exist in the apparatus under test and enables the location of existing or imminent difficulties. Moreover, government regulations require that minimum operating characteristics be maintained. Constant check, for example, requires the use of monitors to indicate deviation of the carrier frequency from its assignment and modulation percentage. Characteristics of the equipment may thereby be kept at a satisfactory maximum with consequent savings in components that could become damaged through prolonged harmful operation, and direct economies can be realized by the elimination of considerable lost air time. To enable your engineer to obtain reliable indications, test equipment must be of high quality and contain far better characteristics than the apparatus on which tests and measurements arc to he made. The test equipment listed below fills these requirements. They are all manufactured by concerns known for quality and reliability. FM Monitor, Hewlett- Packard Type 335B Noise and Distortion Meter, Hewlett -Packard 330 Series Distortion and Noise Meter, General Radio Type A Attenuator Network, Davcn Type 740 You can get every test and monitoring equipment you need from Collins. Save yourself time, and place all equipment responsibility on one reliable company - Collins. Connections are constantly maintained with all the approved suppliers of test and monitor - ing equipment. Ask for quotations on the models you want. r Audio Oscillator, General Radio Type A Range Extension Filter for A, General Radio Type P1 Audio Oscillator, Hewlett -Packard Type 201 -B Audio Oscillator, Hewlett -Packard Type 206 -A AM Modulation Monitor, General Radio Type A AM Frequency Deviation Monitor, General Radio Type A FM Monitor, General Radio Type A General Radio Type A AM Frequency Monitor Page 34

140 42E Series Antenna Tuning Units, 42E-5 Antenna tuning unit with front cover in place Open front view of a 42E-5 antenna tuning unit showing substantial mounting and wiring of all components. Overall dimensions: 27" w, 273/4" h, 27" d. Weight: 117 lbs. Finish: Gray. Collins Part No.: The Collins 42E series comprises a group of specially constructed units to match a vertical radiator to an unbalanced transmission line. The electrical circuit is arranged in the form of either a T section low pass filter or other configuration depending upon the particular application. The use of a T section allows operation over a wide range of antenna impedances without changing the circuit configuration. Line current and antenna current meters are provided as well as a current transformer for a remote meter. A horn gap is provided for lightning protection. The 42E unit is housed in a sturdy weatherproof cabinet constructed of heavy gauge welded steel. It is arranged to mount by means of a 3" pipe support. All components are easily accessible upon removal of the front cover, which is simply lifted upward and outward. Meters are read through two windows in the housing. The meter shorting switches can be operated from the outside. The transmission line and antenna connections are made by means of insulated feed -through bushings on the roof of the cabinet. The unit comes complete with an 8 ft. length of 3" diameter pipe for mounting on a concrete base. A reactance cancelling network for matching shunt fed antennas to a transmission line. Because of the varying requirements of each customer, these units are designed for each specific application. Supply the Collins Radio Company with the following information: Transmitting frequency Impedance of transmission line Tower height Transmitting power 142A SHUNT MATCHING NETWORK Distance to tap from ground Distance from tower to matching unit In general the 142A Shunt Matching Network is housed the same as the 42E Series Antenna Tuning Units with the exception that one antenna current meter only is supplied. The unit includes static drain choke and transformer for remote antenna current meter. See 42E -5 above for dimensions and approximate weight. Page 35

141 Lighting Choke,, Accessories TOWER LIGHTING CHOKES In accordance with government specifications, all towers must be lighted. Collins chokes provide thorough isolation of power lines from the r -f field. They are in all- weather housings complete with mounting brackets. Conduit terminations are provided. m Open view of 23C -1 Type 23C watt single phase 23D watt single phase 23E watt three phase Part No. Weight lbs lbs lbs. BLANK PANELS Useful for filling up unused space in racks and for making special equipment, blank panels have many Height Weight Part Number applications. These panels are drilled to mount in standard 19 inch racks. The thickness is %la" inch. Standard panels are aluminum, with metallic gray finish. Other metals and colors are available on special order. Type 619B Cabinets arc sturdily constructed of sheet metal, conveniently drilled to accommodate standard 19" panels of any height. A hinged full - length rear door provides immediate access to all units mounted in the cabinet. Adequate ventilation is obtained through properly distributed louvers in the door and through an opening in the top that is protected front (lust by a baffle plate. The outside depth of the cabinet is 18 inches. These cabinets are available in metallic gray finish. Black lacquered style strips are furnished with each cabinet. 619B cabinets are furnished in two sizes, the 619B -1 having 77" panel mounting space, and the 619B -2 RACK CABINETS I Enclosed view of 23C oz %z" 1 lb. 4 oz /2" 1 lb. 14 oz lbs. 8 oz /4" 3 lbs. 2 oz ' /1" 3 lbs. 12 oz lbs. 6 oz /4 5 lbs which has 70" panel inowtting space. Overall heights are 83" and 76" respectively. a6, 6 HOLES ,6 NIES s-» Z I 4i 6r96-: l r,. CABINET OBI 6 ' PAT 6 _ 6I96-H Top 000, HANDLE Bottons PP Page 36

142 . Custom Designed Audio Equipment /Deigning custom audio equi/un rnt While the regular Collins line of audio equipment is very comprehensive, operating methods in individual stations sometimes demand a special combination of functions in a given piece of equipment, calling for custom building. Recognizing that fact, Collins engineers have designed our standard audio line in such a wav that the standard sub -assemblies can be adapted in any wanted variety to provide custom equipment for special individual requirements, at a surprisingly low increase in cost. The highly skilled engineering group responsible for Collins custom work has had years of experience in broadcasting. and is capable of building anything which may be required by the broadcaster. We also have all facilities for factory wiring and testing and, if desired, will be glad to cooperate with your Chief Engineer in supervising installation. A functional block diagram of the equipment facilities required and a rough physical layout, together with information regarding any special circuit or construction features desired, should accompany your inquiry. A few examples of Collins custom audio equipment are shown on the following page. Page 37

143 Custom Designed Audio Equipment Special music library console Special control console Typical control room rack mounted equipment? ó.,,....,. -, _ - :c..,;;.: 3,. ;.;.. ;;a\....,.'t2rc. ;;,:: `..., Rear view master control rack equipment - custom built for AM.FM operation Page 38

144 Transcription Turntables PRESTO TYPE 62 -A TRANSCRIPTION TURNTABLE PRESTO TYPE 64-A TRANSCRIPTION TURNTABLE The 62 -A consists of a 16" dual speed turntable, Audak lateral magnetic reproducer, compensating network and scratch filter mounted in a wood cabinet. Standard equipment includes the following parts and accessories: Type 10 -A turntable chassis mounted in a 3 -A cabinet, equipped with a 151 -A lateral magnetic reproducer and compensating network, a 501 -A cutoff filter, a 601 -A sapphire reproducing needle, and a 502 -A screwdriver. Frequency response is uniform from 500 to 9000 cycles. Noise level: 45 db below useful sound level. Sapphire reproducing needle pressure: 13/4 oz. Output level approximately -55 dbm. Output impedance: 200 or 250 ohms. Type 505 -A matching transformer is required for 50 or 500 ohms output. The synchronous motor draws 50 watts from a 115 volt, 60 cycle line. The cabinet mounts the table 33" above floor level. Finish: two -tone gray with silver trim. Shipping weight: Collina Part No.: 1 case 95 lbs., 1 carton 10 lbs A turntable A matching transformer The Presto 64 -A transcription turntable is an electro- mechanical gear driven turntable suitable for the most discriminating users. The simplicity of operation permits its use by unskilled persons. Turntable operation and speed change are accomplished by operating a single switch. Two motors are used, one for 78 rpm and the other for 33% rpm. An overrunning clutch disengages the motor which is not energized. The simplicity of the transmission eliminates much noise so that the total program disturbance will be reduced to 50 db below maximum program level. The cabinet mounts the table 33" above floor level. Supplied without reproducers. Power requirements: 75 watts 115 v 60 cps. Dimensions: 24" w, 33" h, 24" d (turntable and cabinet only). Weight: 266 lbs. (lesa reproducer). Collins Part No.: turntable and cabinet only, no reproducer. PRESTO TYPE 63 -A TRANSCRIPTION TURNTABLE The 63 -A is a 16" dual speed turntable mounted in a wood cabinet with chrome trim. The cabinet mounts the table 33" above floor level. Standard equipment : 10 -A turntable chassis mounted in 3 -B cabinet. Shipping weight: 180 lbs. Collins Part No.: turntable and cabinet only, no reproducer. Presto 506 -A arm rest for mounting W. E. 109AA reproducer to 3 -B cabinet Collins Part No.: Illus. No. A-1 A-2 A CONNECTORS (See next page for illustration) Large Howard Jones 4 Connectors Collins Manufacturers Number Number Description P404 CCT Male, cable type S404 CCT Female, cable type P404 AB t/ts Male, chassis mtg AB Female, chassis mtg. Small Howard Jones 4 Connectors P304 CCT Male, cable type S304 CCT Female, cable type P304 CCT -K Male, cable type w /lock S304 CCT -K Female, cable type w/lock P304 AB Male, chassis mtg S304 AB Female, chassis mtg. (Continued next page) Page 39