POSITIVE JAMMING CARRIER SCRAMBLING SYSTEM MODEL--EE-2002 INSTALLATION MANUAL TABLE OF CONTENTS

Transcription

1 POSITIVE JAMMING CARRIER SCRAMBLING SYSTEM MODEL--EE-2002 INSTALLATION MANUAL WRITTEN BY: DALE MARLAND PREPARED BY: PATRICK M. CONWAY TABLE OF CONTENTS 1.0--GENERAL DESCRIPTION 2.0--FRONT PANEL DESCRIPTION 2.1--A Quick Look at the Factory Settings 2.2--Modulation Control 2.3--Power Control 2.4--Carrier Control 2.5--Front Panel Indicators 3.0--REAR PANEL DESCRIPTION 3.1--A Quick Look At The Factory Settings 3.2--Powering 3.3--Pre-emphasis Loop 3.4--Jamming Carrier Loop

2 4.0--INSTALLATION AND SET-UP 4.1--Rack Mounting and Cabling 4.2--Pre-emphasis Loop set up 4.3--Jamming Carrier Loop set up 4.4--Jamming Carrier Modulation set up 4.5--Jamming Carrier Power and External control 5.0--OPERATIONAL CHECK 5.1--Distortions Within the Decoded Channel 5.2--Distortions Outside the Encoded Channel 6.0--APPLICATION NOTES 6.1--MMDS Operation (Single Jamming Carrier Operation) 6.2--SMATV Operation (One Encoder for Many Channels) 7.0--SPECIFICATIONS DIAGRAMS Fig. 1 Front Panel Fig. 2 Front Panel - Close-up Detail Fig. 3 Rear Panel Detail Fig. 4 Cabling Diagram for the EE-2002 Encoder SECTION 1.0 GENERAL DESCRIPTION The EAGLE EE-2002 Positive Encoder is a state of the art, third generation, positive scrambling system intended to encode a Television channel for transmission over todays communication networks. The encoder utilizes two individual jamming carriers, spaced 50 khz apart,

3 centered within the channels passband to prevent reception of the visual and aural content. At an authorized subscribers network connection a passive decoding filter restores the channel by removing the jamming carriers. During the course of this installation manual each section will refer you to a figure, and each step will have the individual control within brackets [ ] which will correspond to the control depicted on the figure. The terms CW and CCW refer to the clockwise or counter clockwise, respectively, rotation of an adjustment control. Individual switch positions within a particular Dip Switch will be referred to as a hyphenated number attached to the Dip Switch letter (example: Dip Switch A, switch position 3, would be switch A-3). SECTION 2.0 FRONT PANEL DESCRIPTION During the course of this installation manual each section The front panel (see figure 1) has controls which are exposed by loosening the two Phillips screws holding the smoked access door and lifting the doors left corner and sliding it to the left. (figure 2 shows a close-up view of the controls section) Figure 1

4 Figure A Quick Look At The Factory Settings Dip Switch A [ 1 ] --- Modulation A khz...off A-2 -- Combined Positive...ON A Hz...OFF A-4 -- Combined Negative...OFF Dip Switch B [ 2 ] ---Power B-1 -- External...OFF B-2 -- Master...ON B-3 -- Oscillator Level...OFF B-4 -- Not Used

5 Dip Switch C [ 3 ] ---Carrier Control C-1 -- Carrier 1 On/Off...ON C-2 -- Carrier 1 Modulation...OFF C-3 -- Carrier 2 On/Off...ON C-4 -- Carrier 2 Modulation...ON LEDs [ 4 ]. [ 5 ], [ 6 ], [ 7 ] & [ 8 ] Power...On upon power up Jamming Carrier 1 ON...On upon power up Jamming Carrier 1 MOD...Flashing upon power up Jamming Carrier 2 ON...On upon power up Jamming Carrier 2 MOD...OFF 2.2 Modulation Control - Dip Switch A [ 1 ] Dip Switch A is the first 4 position switch on the left viewable through the front panel access. Only one of these switches should be on, as they control which of the four available types of modulation is routed to the carrier control switches. Switch A-1, when ON delivers a 1.50 khz continuous tone to the Carrier Modulation switches. Switch A-3, when ON, delivers a 10 Hz tone. Switch A-2 and A-4 combines the two continuous tones into a complex multi-tone signals,combined Positive and Combined Negative respectively. 2.3 Power Control - Dip Switch B [ 2 ] Dip Switch B is the middle 4 position switch viewable through the front panel access. In the ON state Switch B-1 transfers control of the jamming carrier activation to the miniature phono jack on the rear panel labeled

6 EXT. The jack is a two conductor version, and shorting the conductors together with a timer or relay will activate the jamming carriers. Switch B-2 is the Master power switch for the jamming carriers and will over-ride the off, or open, state of the External jack allowing immediate front panel activation. Switch B-3 is used to control the output level range of the jamming carriers. In the OFF state the range is from approximately +20 dbmv to +40 dbmv. In the ON state the range is shifted to +30 dbmv to +50 dbmv. Switch B-4 is unused at this time. 2.4 Carrier Control - Dip Switch C [ 3 ] Dip Switch C is the 4 position switch on the right when viewed through the front panel access. Dip switch C-1, in the ON state, will power jamming carrier 1 when either the master power or the external jack switches are in the ON state. Dip switch C-2 when On will transfer the selected modulation tone to carrier 1. Dip switches C-3 and C-4 will control jamming carrier 2 in the same way as Dip switches C-1 and C-2 respectively control jamming carrier Front Panel Indicators The five LED indicators viewed through the front panel access from left to right are: LED1 [ 4 ] Power indicator --A steady light when power is applied to the chassis. LED 2 [ 5 ] Carrier 1 ON indicator -- A steady light when power is applied to the circuitry for carrier 1. LED 3 [ 6 ] Carrier 1 Modulation -- A flashing light when modulation is applied to carrier 1. LED 4 [ 7 ] Carrier 2 ON indicator-- A steady light when power is applied to the circuitry for carrier 2. LED 5 [ 8 ] A flashing light when modulation is applied to carrier REAR PANEL DESCRIPTION The rear panel may be divided into three sections, the powering section on the far right, the pre-emphasis loop in the center, and the jamming carrier loop on the left. (see figure 3)

7 Figure A Quick Look At The Factory Settings Stage 1...Fully CW to Maximum Pre-emphasis Stage 2...Fully CW to Maximum Pre-emphasis Carrier Level...Mid Range 3.2 Powering The EE-2002 utilizes a universal power entry module [ 9 ] that is capable of accepting either 115 VAC or 230 VAC at 50 to 60 Hz. The selected voltage shows through a window on the face of the power entry module and may be changed by opening the module and rotating the selector until the correct voltage for your application is present. The fuses for the power line are also contained within the entry module. The 3mm phono jack labeled EXT. [ 10 ] accepts a 2 conductor 3mm plug and may be used to externally activate the jamming carriers. If the Master Power is in the up (OFF) and Ext. Power switch is down (ON) the shorting of the two conductors will present power to the jamming carrier selection switch and activate any selected jamming carriers. Opening the two conductors will deactivate any jamming carriers.

8 3.3 Pre-Emphasis Loop The Pre-Emphasis Loop has an IF Input [ 11 ], an IF output connector [ 12 ], and two potentiometer controlled stages of pre-emphasis. The preemphasis added to the IF signal helps to counter the effect of the loss to video resolution that occurs when the decoding filter is placed in an authorized subscribers signal drop. Stage 1 [ 13 ] has the capability of adding approximately 15 db of pre-emphasis to the center of the channels bandwidth. The second stage (Stage 2 [ 14 ]) has the capability of approximately 15 db of pre-emphasis with group delay compensation by altering the vestigial sideband shaping. The two stage variable approach allows the system to better match the decoding filters loss and delay characteristics on a per channel basis. 3.4 Jamming Carrier Loop The jamming carrier loop has an IF Input [ 15 ], an IF Output [ 16 ], and one variable Bridged T Attenuator labeled Carrier Level [ 17 ]. The jamming carrier loop will combine the activated jamming carriers into the IF passband with their amplitude being varied with the carrier level control. 4.0 INSTALLATION AND SET UP The following installation and alignment procedure assumes that the EE-2002 is being installed into a traditional CATV headend. For alternate signal delivery technologies see section 6.0 APPLICATION NOTES. 4.1 Rack Mounting And Cabling The EE-2002 is a 19 inch wide rack mount device that consumes 1/2 of a traditional rack space height or 1.75 inches. The encoder should be mounted near the modulator of the channel to be encoded. Prior to connecting the EE-2002 into the modulators IF Loop the Modulator and Video source should connected and aligned to the manufactures specifications.(see Fig. 3, page 7 and Fig. 4, page 9A for reference on the following connections) Screw the 6ELP-3 filter onto the Pre-Emphasis In connector (Item 11). Now connect a section of cable from the 6ELP-3 to the modulator's IF output. The Pre-emphasis Loop Out (Item 12) must then be cabled to the Jamming Carrier Loop In (Item 15). The Jamming Carrier Loop Out (Item

9 16) should then be cabled to the modulator's IF Input. Insure that the rear panel Power Entry Module (Item 9) has the correct voltage setting for the installation site and then attach the power cable to the unit. Initially check that the Front Panel Indicators display per section 2.5 of this manual. Cabling Diagram For the EE-2002 Encoder Figure 4 Cabling Your EE2002: 1. Place the 6ELP-3 on the IN connector (11) of the Pre- Emphasis of the EE Connect a coax cable leading from the OUT connector of the IF loop on your modulator to the 6ELP-3 which is connected to the Pre-Emphasis IN (11). 3. Connect a coax cable leading from the IN connector of the IF loop on your modulator to the OUT connector of the Jamming Carrier (16). 4. Connect a coax cable leading from the Pre-Emphasis OUT (12) to the Jamming carrier IN (15). 4.2 Pre-emphasis Loop Set Up Turn the master power switch (Switch B-2) into the up or off state to turn off the jamming carriers. (Note that LED 2 and 4 extinguish)

10 Utilizing a good quality Television Receiver, or a demodulator and waveform monitor viewing VITS signals, place a decoding filter between the modulators RF output and the TVs or demodulators input. Align the Stage 1 and / or the Stage 2 pre-emphasis controls to achieve the sharpest picture or in the case of the waveform monitor the best VITS restoration. Once you have achieved the best quality picture with a decoding filter in the receive path note the Stage 1 and Stage 2 adjustment positions relative to the graduated marks on the rear panel for future reference. 4.3 Jamming Carrier Loop Set Up Turn the master power switch (Switch B-2) into the down or on state to restore the jamming carriers (Note that LED 2 and 4 return on). Connect a spectrum analyzer to the modulators RF output without the decoding filter in the line and note the amplitude of the channels video carrier. Move the analyzers center frequency to a position that is one half the distance between the visual and aural carriers. In a system M,N this would be 2.25 MHz above the channels video carrier frequency ( one half of the 4.5 MHz visual to aural difference ). Now expand the frequency per division and the video resolution of the spectrum analyzer to display the two jamming carriers that are 50 khz apart. Using the Jamming Carrier Level control adjust the level of the lower carrier to equal the visual carrier amplitude. If using a field strength meter as an amplitude measuring device, after turning the master power switch to its ON state turn the Carrier 2 ON (Switch C-3) to the up or OFF state and Carrier 1 Modulation (Switch C-2) to the up or OFF state to deliver only 1 unmodulated carrier to the modulators IF loop. (Note that LED 3,4, and 5 are off) Tune the field strength meter to the visual carrier frequency and note its amplitude, then tune the field strength meter to the frequency that is one half of the difference between the visual and aural carriers of this channel (2.25 MHz above the visual carriers frequency in a M,N system) and adjust the Jamming Carrier Level control to match the amplitude noted for the visual carrier frequency. Restore the Carrier 1 Modulation Switch and the Carrier 2 On switch to the On or down position. 4.4 Jamming Carrier Modulation Set Up The factory set modulation is Switch A-2 On to supply the carrier modulation switches with a 1.5 khz tone which is gated off to a high level at the 10 Hz rate. The other 3 switches, A-1, A-3,and A-4 will deliver to the carrier modulation control switches a 1.5 khz continuous tone, a 10 Hz continuous tone, or a complex modulation of a 1.5 khz tone gated to a

11 low state at the 10 Hz rate, respectively. Any of these may be used as a modulation source, each with its own characteristics. Both jamming carriers have the ability to be modulated or left in its unmodulated state by the Carrier Modulation switches (Switches C-2 and C-4). This is useful when measuring for FCC frequency compliance as an unmodulated carrier is easier to inject into a frequency counter. 4.5 Jamming Carrier Power and External Control The presence of the jamming carriers may be controlled in three manners. The first is individual control by the use of the Carrier On switches (Switch C-1 and C-3 down for that carrier ON). The second is with the Master Control Switch (Switch B-2 down for power to the Carrier ON Switches). This switch will control any of the jamming carriers selected for control by the Carrier On switches. The third manner of control is through the use of the External Control Switch ( Switch B-1 Down for transfer to the rear panel if the Master Switch is up) which will transfer the control of any jamming carriers selected for activation by the Carrier On switches to a jack on the rear panel of the EE-2002 chassis. Shorting the conductors of the rear panel jack will activate any selected jamming carriers. 5.0 OPERATIONAL CHECK Two methods of operational check are available depending upon equipment availability. The encoded channel should be combined into the distribution network and a good quality Television Receiver or a Spectrum Analyzer may be employed to view the encoded and decoded channels appearance. 5.1 Distortions Within the Decoded Channel If after placing the decoding filter into the drop path a distortion is viewable (normally in the form of diagonal bars or stripes) recheck the level of the jamming carriers relative to the visual carrier. If the levels are correct you may assume that the distortion is occurring within the modulator. This distortion is normally due to the additional energy presented to the output mixer of the modulator due to the addition of the jamming carriers.

12 A 6 db pad between the Jamming Carrier Loop output of the EE-2002 and the IF input of the modulator will usually lower the overall power presented to the output mixer of the modulator sufficiently to prevent the distortion. The same effect may be viewed upon a spectrum analyzer that is displaying the entire channels output bandwidth and looking for Spurs which present themselves only with the inclusion of the jamming carriers. 5.2 Distortions Outside the Encoded Channel In some cases the distortions generated by the output mixer of the modulator are of sufficient magnitude as to affect other channels within the system. The same remedy as implemented above will return the modulator to a clean output. There is one instance where the distortion is not generated by the marriage of the EE-2002 to the modulator. This is where the distortion is formed within the Television Receiver itself. You can easily distinguish this distortion from others due to the fact that it occurs only in a nonsubscriber, and the placement of a decoding filter prior to the sets input will remove the distortion on adjacent channels. This distortion is occurring due to the fact that the TVs IF filter is allowing the jamming carriers to blow through to the demodulation circuitry. The remedy for this problem is the placement of a positive and a negative filter on that subscribers drop to eliminate the jamming carriers and notch out the visual carrier to prevent the reception of the channel, or the placement of a special CV filter for that channel which accomplishes the same end result by lowering both the jamming carriers and the visual carrier by approximately 15 db. 6.0 APPLICATION NOTES The following application notes cover two alternate technologies for the delivery of premium channel programming and how they may affect the traditional set-up of the EE-2002 encoder. 6.1 MMDS Operation ( Single Jamming Carrier Operation ) In an MMDS or single channel microwave delivery technology the primary transmitter intended to deliver the visual content of the channel has insufficient output capability to handle the additional energy of the

13 two jamming carriers. In this case the jamming carrier must be transported on a separate transmitter operating at the same output frequency. The IF loop for the primary transmitter should be broken and cabled to the Pre-emphasis loop, out to in and out to in respectively. The Jamming Carrier Loop should have its input terminated with 75 ohms and the output delivered to the secondary transmitters IF input. In this manner the video information may be pre-emphasized to compensate for the decoding filters loss and the jamming carriers may be transported over a separate transmitter, all with one EE In addition the unmodulated jamming carrier may be turned off by the carrier control switch to lower the required secondary transmitters power capability requirement. 6.2 SMATV Operation ( One Encoder For Many Channels ) In the case of a SMATV or small operator who wishes to secure many channels in the Low-band or lower Mid-band a single EE-2002 may be utilized to encode more than one channel. The highest frequency channel of those intended to be encoded may make use of the Pre-emphasis Loop Of the EE-2002 and may be connected as described above, IF out of the modulator to the Pre-emphasis Loop IN of the EE-2002 and the Pre-emphasis Loop Out of the EE-2002 to the Modulators IF input. Then the Jamming Carrier Loop In of the EE should be terminated with 75 ohms and the Jamming Carrier Loop Out may be split by the desired number of channels to be encoded. The splitter must have equal losses to each leg and all modulators must have the same IF Loop levels. Next each modulator would require a two way splitter, used as a combiner, placed into its IF Loop with the common of the splitter facing the IF Input. Each splitter would then receive a cable from the divided Jamming Carrier Loop output inserting the jamming carriers into each modulators RF output. 7.0 SPECIFICATIONS POWERING 115 OR 230 VAC 50 T0 60 Hz

14 PRE-EMPHASIS RESPONSE Stage 1--Approx. +15 db of active continuously variable gain Stage 2--Approx. 15 db of passive continuously variable gain JAMMING CARRIERS J.C. 1 J.C. 2 Model (System) System M,N System M,N offset System D,K,L System D,K,L System B,G,H System B,G,H Eagle Comtronics, Inc Waterhouse Road Clay, New York (315) FAX (315) Copyright 2000 Eagle Comtronics, Inc. All Rights Reserved.