BEARS 1 AUDIO CONTROL SYSTEM INSTRUCTION MANUAL B1-0080 W. Savold KØDKT 2/7/09 ACU instruction (B1-0080).
BEARS 1 AUDIO CONTROL SYSTEM INSTRUCTION MANUAL CONTENTS Page Section 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.
BEARS 1 Audio Control System 1. DESCRIPTION The audio control system (ACS) was designed to meet the requirements of the Brevard Emergency Amateur Radio Services, Inc. for the BEARS 1 vehicle. The system allows all receiver and transceiver audio at a communications operating position to be monitored through a single speaker or a headset. Seven audio inputs are provided and any combination may be monitored. Each input has it’s own independent volume control.
2. SPECIFICATIONS Receiver Inputs: Inputs: 7 inputs are available and may be monitored simultaneously Input Impedance: 8 Ohms Single ended (negative ground) Activity Monitors: LED full bright: 190 mV in Threshold: 115 mV in High Pass Filter: -18dB down at 100 Hz. Microphone Input: Inputs: 2 inputs selectable by a front panel switch Input Impedance: 10K Ohms (for Heil HC-5 microphone elements) Level Monitor: LED threshold: 3 mV microphone input (approx. 4.
3. PANEL CONTROLS 17 1 2 3 5 4 6 7 8 16 11 9 10 12 13 14 15 1. Speaker 2. Power ON/OFF switch 3. LED display dimmer control 4. Speaker / Phone Switch Directs received audio to the speaker or headphones. The switch center position mutes both speaker and headphones. 5. Radio I.D. Label indicates which radios are available or installed. The paper label is held in place by a slotted cardholder allowing easy modification if the radio complement is changed. 6.
12. ICS Volume Control and Activation Switch Pull to activate the ICS system. This disables the microphone from the transmitters. The system now operates in full duplex mode via the headset. Push the VOL control "in" to disable the ICS system and return to normal radio operation. While the ICS system is activated, the radio activity LED's continue to operate. Radio audio is mixed with the ICS audio. Transmitting, however, is not possible. Rotate the VOL control to adjust ICS audio to the headset.
4. REAR PANEL INTERCONNECT 19 18 20 23 21 22 24 25 18. ICS connector to ICS J-box J14 -- RJ-45 jack 19. Receive audio inputs from receivers/transceivers J1 through J7 – RCA phono jacks – 8 ohm 20. Transmit audio and PTT output to transceivers J8 through J13 – 6 pin DIN jacks 250 mV mic audio Ground for PTT 21. Remote PTT input J19 – RCA phono jack Ground for PTT 22. AUX Audio J15 – RJ-45 jack Supervisor audio out PA audio out TV audio in 23.
28. 13.8 VDC input. Pendant cable with Anderson Power Pole connector 5. SET-UP CONSIDERATIONS It is important to set the volume control on the radios to the appropriate levels during initial setup. Setting them too high will cause considerable distortion within the system. The input circuitry was designed to use audio from the speaker output jack with the volume control set to comfortable listing level using the radio’s internal speaker.
6. TROUBLESHOOTING If the Audio Control Panel seems to be malfunctioning, please check to be sure power is turned on to the Operating Position, the Audio Control Panel, and the transceiver / receiver you wish to use. If the Panel still does not work, try the following before reporting a malfunction.
7. ADJUSTMENTS There are relatively few adjustments within the Audio Control Unit; however, the following adjustments are possible if at some time they are felt needed. Appendix 2 shows the location of the adjustments on the circuit boards. 7.1 Speaker Output Level. The speaker output level is set by R22 on the Amp & P.S. Board. This adjustment is set to maximum and may be reduced if desired.
8. ADAPTING TO OTHER RADIOS The Audio Panel is designed to accept single ended (one side grounded) audio from receivers and provide transmit audio output at a level of 250 mV peak. Adapter cables are used to custom tailor these signal levels to various radios used. Appendix 1 contains the schematics for the adapter cables designed for the initial configuration of BEARS 1. The following describes the considerations for adapting other radios to the Audio Panel.
Attenuator Test Setup The adapter cable schematics in Appendix 1 serve as examples of various cable designs.
9. BLOCK DIAGRAMS Block diagrams of the Audio Control System elements are shown in Appendix 4. The following is a basic description of some of the “blocks” that may or may not be obvious. Please refer to the ACS Block Diagrams sheets A4-1 and A4-2 when reading the following. A. Audio Amplifier: This is a Voltage gain of ten amplifier used to amplify the audio level from the external speaker jack of the receiver/transceiver to a relatively high level for switching.
G. Supervisor Audio Output: The Supervisor Audio Amplifier combines receive audio with transmit audio. Transmit audio is derived from sidetone. The level of both signals is set by the operator for comfortable listening. The amplifier also drives the 100 Ohm Cat 5E cable to the supervisors panel. H. Transmit Audio Out: Six buffer amplifiers are used to drive and isolate the microphone adapters for the various transceivers used. The audio out of these amplifiers is active all the time and identical.
L5. Call Decoder: The Call Decoder takes in the 3 wire BCD discretes from the 6 ACU’s and converts them back into decimal (6) call discretes. The call discretes are wired to the appropriate panels to signal that they are being called. L6. ICS Summing Amplifier: The ICS Summing Amplifier takes in the audio from up to 6 other operating positions and sends the summed output back to the positions. The amplifier is required to drive the 6 100 Ohm Cat 5E cables back to the ACP’s at the operating positions. M.
APPENDIX 1 Audio Panel Connectors MODULAR JACKS (1) PIN COLOR ICS AUX AUDIO SUPERVISOR J14 J15 (2) JI6 WHT/ORG ICS AUDIO IN S-AUDIO OUT HI POS 1 AUDIO HI LOAD + 2 ORG/WHT ICS AUDIO COM S-AUDIO OUT COM POS 1 AUDIO COM LOAD - 3 WHT/GRN MIC AUDIO OUT PA AUDIO HI POS 2 AUDIO HI CLOCK + 4 BLU/WHT SIG 1 REC #6 LO POS 3 AUDIO COM DATA - 5 WHT/BLU SIG2 REC #6 HI POS 3 AUDIO HI DATA + 6 GRN/WHT MIC AUDIO COM PA AUDIO COM POS 2 AUDIO COM CLOCK - 7 WHT/BRN SIG 4 TV HI POS 4 A
APPENDIX 2 Adjustment locations Transmit Audio Board Remove bottom cover of Audio Panel for access. Boom Mic Gain Headset Mic Gain Master Mic Gain Amplifier & P.S. Board Remove bottom cover of Audio Panel for access. This board is located on the right side panel when facing the front of the panel.
APPENDIX 2 Adjustment locations (continued) ICS Board Remove the top cover of the Audio Panel for Access. The board is located on the right side when facing the front of the panel.
APPENDIX 3 ADAPTER CABLE SCHEMATICS Adapter Page Yaesu FT-8800 20 Icom 706 21 EF Johnson Challenger 22 Relm RMU 45 23 Motorola Spectra 24 Cobra CB 25 MA/Com EDACS 26 Boom Microphone Cable 27 Jack Panel Cable 28 19
APPENDIX 4 Block Diagrams 29
APPENDIX 4 Block Diagrams 30
NOTES: 31
