Installation and Operation Manual. Model 437 Audio Control Amplifier

Transcription

1 Installation and Operation Manual Model 437 Audio Control Amplifier SM437 ISSUE 2.00 Northern Airborne Technology Ltd Kirschner Road Kelowna, BC, Canada. V1Y 4N7 Telephone (250) Facsimile (250) Issued on the authority of Northern Airborne Technology Ltd. Copyright 2005

2 Northern Airborne Technology Ltd. has acquired the assets of db Systems Inc., and has reissued this manual in full NAT format. Northern Airborne Technology Ltd. will be responsible for all future amendments and revisions. Installation and Operation Manual Page ii ENG-FORM: DOT

3

4 Table of Contents Section Title Page 1. Description 1.1 Introduction Product Description Design Features Specifications Electrical Specifications Physical Specifications Environmental Specifications Product Approval Model 437 Nomenclature Installation 2.1 Introduction Unpacking and Inspection Warranty Continued Airworthiness Installation Procedures Warnings Cautions Cabling and Wiring Mechanical Installation Electrical Installation Pin Identification Modes of Operation Interconnect Information Post-Installation Checks Adjustments Accessories Required But Not Supplied Installation Drawings Operation 3.1 Introduction General Information Controls and Indicators 3-1 Installation and Operation Manual Page iv ENG-FORM: DOT

5 Section 1 Description 1.1 Introduction Information in this section consists of product description, design features and specifications for the Model 437 Audio Control Amplifier. Information on the and is included in this manual. For information on other derivative products, please contact Product Support at NAT Ltd. Review all notes, warnings and cautions. 1.2 Product Description The Model 437 Audio Control Amplifier is a remotely controlled intercom/audio amplifier, which operates upon command from switches and potentiometers in the cockpit. The Model 437 is capable of switching up to 14 receivers, 4 sidetone inputs and an interphone line. Five unswitched and unmuted inputs are also provided to accommodate an aural warning input and 4 auxiliary inputs. Headphone and Selected Speaker outputs are isolated and a Cockpit Voice Recorder output provides summation of headphone, speaker and microphone audio. Microphone audio is recorded on the Cockpit Voice Recorder at all times with the Model 437 (i.e. the microphone to Cockpit Voice Recorder audio channel is unswitched and unmuted). 1.3 Design Features Headphone and Speaker channels are powered from separate 28 Vdc power inputs so that one channel will still operate if the other fails. Receivers and operating modes are electronically switched. The electronic switches in the Model 437 are enabled by ground signals, supplied by manual switches in the cockpit. Selective voice or code filtering is provided on four of the receiver audio inputs, intended for ADF and NAV audio. The filter function is electronically controlled by ground signals from the cockpit Voice-Off- Range switch. A voice-activated switch is incorporated in series with the microphone input to reduce interphone noise. This feature allows Hot Interphone operation without ambient noise being coupled into the amplifier when the pilot is not talking. The threshold of voice activation may be adjusted by a screwdriver adjustment through an access hole in the Model 437 cover (marked THLD). It is factory set at 100 millivolts and adjustable from 15 to 150 mv. The microphone to Cockpit Voice Recorder audio channel does not employ the Voice Activated Switch circuitry. Section 1 Rev: 1.00 Issue 2 Page 1-1 ENG-FORM: DOT

6 1.4 Specifications Electrical Specifications The Model 437 is intended for aircraft with two cockpit audio stations. Two Model 437 amplifiers are installed, one for each audio station. The receiver outputs are connected to both Model 437 receiver inputs. The receiver input impedance of the Model 437 is 1000 ohms, so when the two amplifiers are installed, the receiver sees 500 ohms. Input specifications are expressed in Vrms, rather than milliwatts, to avoid misunderstanding. Inputs COMM RCVR FLTR AUX AW MIC Headphone Volume Speaker Volume Sidetone Volume 4 dual audio inputs for receiver and sidetone. Receiver input level is 7.75 Vrms and Sidetone is 3.87 Vrms, both switched simultaneously. 6 single, switched audio inputs for MKR, DME, TACAN, etc. Input level is 7.75 Vrms. 4 single, switched audio inputs for NAV, ADF, etc Vrms inputs have selective filtering, switched by the Voice-Off-Range switch. Voice: 1020 ± 5 Hz, 30 db, 100 Hz notch Range: 1020 ± 5 Hz Ident Tone emphasis 4 unswitched and unmuted auxiliary inputs, factory set to accommodate 3.87 Vrms. The AUX screwdriver adjustment may be changed for higher or lower levels. This is an unswitched and unmuted input compatible with the aural warning output of the Model 207 or equivalent, which provides Stall, Altitude Alert, Landing Gear, Take-Off-Out-Of- Trim, Decision Height and Autopilot Disconnect warning tones. Input varies with tone, approximately 4 VPP into 15K. The microphone input, used for interphone mode, supplies bias and is compatible with carbon and amplified dynamic microphones. Voice activated within 1.5 milliseconds by a circuit that provides 30dB minimum attenuation within 2 seconds after speech mv threshold range. Controls level of all audio inputs except sidetone, auxiliary and aural warning. Volume control range is 30dB (minimum) controlled by a 10,000-ohm ½ watt linear pot. Maximum volume is with maximum resistance. Same as Headphone Volume specification. Same as Headphone Volume specification. Outputs Headphone The headphone output will deliver up to 80 milliwatts into 600 ohms continuously. Above that level, peaks will be clipped but it will not damage the amplifier. Rated & Continuous power specification are the same. Section 1 Rev: 1.00 Issue 2 Page 1-2 ENG-FORM: DOT

7 Voice Recorder Speaker Frequency Response Harmonic Distortion Power Supply Isolation Between Channels Output Noise This output will deliver 1 milliwatt into 600 ohms continuously. Rated and continuous power ratings are the same. The speaker amplifier is designed for speech signals and has both a rated power and a Continuous Power specification. The continuous rating is the power the amplifier can continuously deliver with a sine wave. The Rated Power specification is the peak power it can deliver without clipping. Bench testing and adjustment may require brief periods of sine wave operation above the continuous rating, those periods should be limited to 1 minute to prevent amplifier damage. Load Rated Power Continuous Power 4 ohm 10 Watts 1 Watt 8 ohm 8 Watts 0.8 Watts Flat within 3 db from 350 Hz to 6000 Hz. Less than 3 percent distortion, all outputs. 28 Vdc, 1 Ampere maximum. 60 db Minimum Greater than 60 db below rated, all outputs Physical Specifications Height Depth Width 1.93" (49.02 mm) max Weight 1.45 lbs (685 g) Mounting 4.93" ( mm) max including flanges 7.30" ( mm) max including flanges Any attitude Environmental Specifications Temperature Altitude Humidity Shock -55 o C to +70 o C 70,000 feet 95% 48 hours 6g for 11 ms in all axes Qualification of the Model 437 Audio Control Amplifier was completed in accordance with RTCA DO-160A Environmental Categories: F2A/JLO/XXXXXXX/BZ/AAA Product Approval FAA: TSO-C50c (RTCA/DO-170 Class Ib, RTCA/DO-160A) Section 1 Rev: 1.00 Issue 2 Page 1-3 ENG-FORM: DOT

8 1.5 Model 437 Nomenclature The Model 437 derivatives are listed below: Model Model Same as Model 437 base except that it allows increased Cockpit Voice Recorder levels for use on Beech 1900 aircraft with low Comm and Receiver output levels. Same as Model 437 base except that it allows increased Cockpit Voice Recorder levels for use on Beech 1900 aircraft. Contact Product Support at NAT Ltd for further information. Model Same as Model 437 base except that it allows increased Cockpit Voice Recorder levels to improve reception of audio signals by solid state CVR s. Section 1 ends Section 1 Rev: 1.00 Issue 2 Page 1-4 ENG-FORM: DOT

9 Section 2 Installation 2.1 Introduction Information in this section consists of unpacking and inspection procedures, installation procedures, postinstallation checks and installation drawings for the Model 437 Audio Control Amplifier. Review all notes, warnings and cautions. 2.2 Unpacking and Inspection Unpack the equipment carefully and locate the warranty card. Inspect the unit visually for damage due to shipping and report all such claims immediately to the carrier involved. Check that all items listed below are present before proceeding and report any shortage immediately to your supplier: - Warranty Card - Certificate of Conformity or Release Certification Warranty All Northern Airborne Technology Ltd. products are warranted for 2 years from date of installation by an authorized NAT dealer, to be free of defects in workmanship or performance. This warranty covers all materials and labour, but is exclusive of any transport to deliver the defective unit to and from NAT or its designated warranty repair center, or any labour to remove or re-install the defective unit in the aircraft. Contact NAT for any questions regarding this warranty, its applicability to your units and/or for return authorization. NAT is the final arbitrator concerning warranty administration. Units which have been physically damaged, burned, immersed in water or otherwise abused beyond the scope of normal use will not be considered for warranty. WARRANTY IS VOID UNLESS THE PRODUCT IS INSTALLED BY AN AUTHORIZED NAT DEALER. Product for which a warranty card is not returned shall be warranted from date of manufacture. 2.3 Continued Airworthiness Maintenance of the Model 437 Audio Control Amplifier is on condition only. Periodic maintenance of this product is not required. 2.4 Installation Procedures Warnings WARNING: High volume settings can cause hearing damage. Set the headset volume control to the minimum volume setting prior to conducting tests, and slowly increase the headset volume to a comfortable listening level. Section 2 Rev: 1.00 Issue 2 Page 2-1 ENG-FORM: DOT

10 2.4.2 Cautions CAUTION: In all installations, use shielded cable exactly as shown, and ground only as indicated. Significant problems may result from not following these guidelines. Failure to follow the installation and wiring instructions provided in this manual for power and ground connections, including the rating of the circuit breaker, may lead to damage in the power input circuitry of the unit Cabling and Wiring All wire shall be selected in accordance with the original aircraft manufacturer's Maintenance Instructions or AC B Change 1, Paragraphs through Unshielded wire types shall qualify to MIL-W as specified in AC B Change 1, Paragraphs 11-85, 11-86, and listed in Table For shielded wire applications, use Tefzel MIL-C shielded wire with solder sleeves (for shield terminations) to make the most compact and easily terminated interconnect. Follow the connector map in Section 2.7 as required. Allow 3" from the end of the shielded wiring to the shield termination to allow the connector hood to be easily installed. Reference the interconnect drawing in Section 2.7 for shield termination details. Note that the hood is a "clamshell" hood, and is installed after the wiring is complete. Maintain wire segregation and route wiring in accordance with the original aircraft manufacturers Maintenance Instructions. All wiring shall be AWG, except speaker amplifier lines (pins 9-12 and of P40), which shall be AWG. Reference the Interconnect drawing for additional specifications. Check that the ground connection is clean and well secured, and that it shares no path with any electrically noisy aircraft accessories such as blowers, turn and bank instruments or similar loads. Power to this unit must be supplied from a separate circuit breaker or fuse (fast blow), and not attached to any other circuit breaker without additional protection. Verify that the selected circuit breaker size and wire gauge are adequate for the installation using the techniques specified in AC B Change 1, Paragraphs through and through Mechanical Installation The Model 437 may be mounted in any position. No shock or vibration isolators are required. The amplifier may be mounted to metal or plastic surfaces but it is necessary to ground the case to the aircraft structure. When mounting to a plastic surface, a grounding strap must be used. The case is finished with an electrically conductive film, so it is not necessary to remove the film with a bonding brush. It is recommended that the amplifier be installed so that the screwdriver adjustments are easily accessible Electrical Installation Connections to the Model 437 are made through two 'D' subminiature connectors. See section 2.5 for information on the connectors and Installation kits. Section 2 Rev: 1.00 Issue 2 Page 2-2 ENG-FORM: DOT

11 2.4.6 Pin Identification P40 Pin Identification The table below shows the pin identifications for the 37-pin connector (P40): PIN DESCRIPTION PIN DESCRIPTION 1 No Connection 20 INPH AUDIO 2 XMT PTT 21 SIDETONE ENABLE 3 MIC HI 22 HDPH VOLUME 4 HDPH HI 23 INPH KEY 5 HDPH 28VDC 24 MIC LO 6 HDPH LO 25 INPH TO SPKR SW 7 HDPH PWR GND 26 HDPH PWR GND 8 CVR HI 27 CVR LO 9 SPKR 28VDC 28 AUDIO COMMON (SPARE) 10 SPKR 28VDC 29 SPKR LO 11 SPKR HI 30 SPKR PWR GND 12 SPKR PWR GND 31 SPKR PWR GND 13 AURAL WARN LO 32 AURAL WARN HI 14 AUX 1 LO 33 SPKR SW 15 AUX 2 LO 34 SPKR VOLUME 16 AUX 3 LO 35 AUX 1 HI 17 AUX 4 LO 36 AUX 2 HI 18 AUX 4 HI 37 AUX 3 HI 19 CHASSIS GROUND P50 Pin Identification The table below shows the pin identifications for the 50-pin connector (P50): PIN DESCRIPTION PIN DESCRIPTION PIN DESCRIPTION 1 NAV 2 HI 18 NAV 1 HI 35 NAV 2 SW 2 ADF 2 HI 19 DME 1 HI 36 NAV 1 SW 3 MKR 1 HI 20 DME 2 HI 37 ADF 1 SW 4 MKR 2 HI 21 DME 1 SW 38 ADF 2 SW 5 MKR 1 SW 22 NAV 2 LO 39 IDENT SW 6 DME 2 SW 23 ADF 2 LO 40 VOICE SW 7 MKR 2 SW 24 MKR 1 LO 41 DME 1 LO 8 COMM 1 SW 25 MKR 2 LO 42 DME 2 LO 9 COMM 2 SW 26 ADF 1 LO 43 COMM 4 LO 10 COMM 3 SW 27 COMM 3 LO 44 SPARE 2 LO 11 COMM 4 SW 28 COMM 2 LO 45 SPARE 1 LO 12 NAV 1 LO 29 COMM 1 LO 46 No connection 13 COMM 1 SIDETONE 30 COMM 1 HI 47 SIDETONE VOLUME 14 COMM 2 HI 31 SPARE 2 SW 48 SPARE 1 SW 15 COMM 2 SIDETONE 32 SPARE 2 HI 49 SPARE 1 HI 16 COMM 3 HI 33 COMM 4 SIDETONE 50 COMM 4 HI 17 COMM 3 SIDETONE 34 ADF 1 HI Section 2 Rev: 1.00 Issue 2 Page 2-3 ENG-FORM: DOT

12 2.4.7 Modes of Operation The Model 437 can be configured for several different modes of operation by applying a ground signal to the appropriate connector pin (see below): Pin No. Identification Function P50-40 Voice Switch Enables notch filter to reject Ident Tone on NAV and ADF audio inputs. P50-39 Ident Switch Enables bandpass filter to emphasize Ident Tone. P40-33 Speaker Switch Connects selected audio to the Cockpit Speaker. P40-23 INPH Key Connects microphone to the interphone line if XMT PTT is not selected. P40-25 INPH to SPKR Connects Interphone Audio to Cockpit Speaker. P40-2 XMT PTT Opens the microphone to interphone circuit and mutes both headphone and speaker audio. Mute level is adjustable. P40-21 Sidetone Enable Connects selected Comm Sidetone to the Headphones and Speaker (if SPKR Switch is on). The control switches shown will switch low-current loads and should have a DC rating of 28 Vdc. Typical switches for this application include Alco MTA series. A single pole, three-position switch is recommended for the Voice-Off-Range switch. Applying a ground signal to both pins P50-39 (Ident) and P50-40 (Voice) simultaneously will result in improper filter operation Interconnect Information Continued on next page Section 2 Rev: 1.00 Issue 2 Page 2-4 ENG-FORM: DOT

13 Interconnect (Continued) Continued on next page Section 2 Rev: 1.00 Issue 2 Page 2-5 ENG-FORM: DOT

14 Interconnect (Continued) Continued on next page Section 2 Rev: 1.00 Issue 2 Page 2-6 ENG-FORM: DOT

15 Interconnect (Continued) Post-Installation Checks If any preset requires adjustment, be sure this is carried out before the aircraft leaves, and that the unit and its mating connector are secured before departure. Make all required log book entries, electrical load, weight and balance amendments and other paperwork as required by your local regulatory agency Voltage/Resistance Checks Do not attach the Model 437 until the following conditions are met. Check the following: a) Check P40 pins <5> <9> and <10> for +28 Vdc relative to ground. b) Check P40 pins <7> <12> <19> <24> <26> <30> and <31> for continuity to ground (less than 0.5Ω). c) Confirm that P40 pins <2> <21> <23> <25> and <33> are grounded (less than 0.5Ω) when the appropriate switches are closed. d) Confirm that P50 pins <8> <9> <10> <11> <5> <7> <21> <6> <48> <31> <36> <35> <37> <39> and <40> are grounded (less than 0.5Ω) when any appropriate switches are closed. Section 2 Rev: 1.00 Issue 2 Page 2-7 ENG-FORM: DOT

16 Power On Checks WARNING: High volume settings can cause hearing damage. Set the headset volume control to the minimum volume setting prior to conducting audio tests, and slowly increase the headset volume to a comfortable listening level. Power up the aircraft s systems and confirm normal operation of all functions of the Model 437. Upon satisfactory completion of all performance checks, make all required log book entries, electrical load, weight and balance amendments and other documentation as required by your local regulatory agency before releasing the aircraft for service. 2.5 Adjustments SPKR AUX THLD There are six adjustment potentiometers that are accessible through the cover of the Model 437 amplifier (see left). They are intended for trimming the relative audio levels to suit individual operator needs. The speaker (SPKR), auxiliary (AUX), threshold (THLD), filter (FLTR), sidetone (SDTN) and mute (MUTE) volume control pots are located on the side of the unit. FLTR SDTN MUTE SPKR: varies speaker audio level (all signals) AUX: varies level of all four auxiliary inputs to speaker and headphones THLD: varies threshold of voice activating the interphone mic input FLTR: varies level of NAV/ADF audio when passed through Voice or Range filter SDTN: varies level of sidetone to the cockpit speaker MUTE: varies level of speaker muting during transmit (XMT PTT depressed) The potentiometers are linear taper, multiple turn (20 turns nominal), and provide full volume when rotated fully clockwise (cw). These potentiometers have been factory set to comply with the requirements of the unit Test procedures. It is important to refer to Table 1 in the Acceptance Test Procedure (see Section 5 of the SM437 Maintenance Manual) if these settings are changed. It is necessary to make the adjustments in the order shown in Table 1 to prevent inadvertently setting an incorrect level. Example: If the MUTE (R53) level is set for.63 Vrms of DME audio into the cockpit speaker during transmit and later the SPKR (R12) pit is turned up, the mute level will also increase. When making any adjustment it is important to understand its relationship to the levels established by the other pots. Section 2 Rev: 1.00 Issue 2 Page 2-8 ENG-FORM: DOT

17 2.6 Accessories Required But Not Supplied To complete the installation, the Model 437 requires two crimp Installation kits, D37SL-IKC and D50SL-IKC. The kits consist of the following: NAT Part #: D37SL-IKC Quantity Description NAT Part # 1 D-min 37 Socket Housing MS Crimp Socket * Jack Screw Set * Lock Clip Set Pin Connector Hood NAT Part #: D50SL-IKC Quantity Description NAT Part # 1 D-min 50 Socket Housing MS Crimp Socket * Jack Screw Set * Lock Clip Set Pin Connector Hood * Use as required 2.7 Installation Drawings DRAWING REV. DESCRIPTION TYPE SERIAL No \ Audio Control Amplifier Outline - Assembly All Section 2 ends following the above documents Section 2 Rev: 1.00 Issue 2 Page 2-9 ENG-FORM: DOT

18 This page intentionally left blank

19

20 Section 3 Operation 3.1 Introduction Information in this section consists of functional and operational procedures for the Model 437 Audio Control Amplifier. 3.2 General Information The Model 437 Audio Control Amplifier is a remotely controlled intercom/audio amplifier, which operates upon command from switches and potentiometers in the cockpit. The Model 437 is capable of switching up to 14 receivers, 4 sidetone inputs and an interphone line. Five unswitched and unmuted inputs are also provided to accommodate an aural warning input and 4 auxiliary inputs. Headphone and selected speaker outputs are isolated and a cockpit voice recorder (CVR) output is the summation of headphone, speaker and microphone audio. Microphone audio is recorded on the CVR at all times (i.e. the microphone to CVR audio channel is unswitched and unmuted). 3.3 Controls and Indicators The Model 437 Audio Control Amplifier has no operator accessible controls. At installation, the Model 437 is provided with several external switches that can be used to modify the operational modes of the unit (see below): Identification Voice Switch Ident Switch Speaker Switch INPH Key INPH to SPKR XMT PTT Sidetone Enable Function Enables notch filter to reject Ident Tone on NAV and ADF audio inputs. Enables bandpass filter to emphasize Ident Tone. Connects selected audio to the Cockpit Speaker. Connects microphone to the interphone line if XMT PTT is not selected. Connects Interphone Audio to Cockpit Speaker. Opens the microphone to interphone circuit and mutes both headphone and speaker audio. Mute level is adjustable. Connects selected Comm Sidetone to the Headphones and Speaker (if SPKR Switch is on). During installation, it may be determined that internal level adjustments are required. Qualified personnel only shall complete internal level adjustments. Section 3 ends Section 3 Rev: 1.00 Issue 2 Page 3-1 ENG-FORM: DOT