Wireless Intercom System Service Manual

()
Table of Contents
Page
Chapter 1
General Description 1-1
Specifications BTR-200 1-1
Controls and Connections 1-2
Front Panel 1-2
Rear Panel 1-5
Chapter 2 - Identification of Circuit Board Revision and Version
Audio Boards ......•.................................................................................................................................... 2-1
Receive Board 2-2
Transmit Board 2-3
Chapter 3 - Transmit, Receive & Audio Circuit Boards
BTR-200 Instrument Disassembly 3-1
Transmit Board 3-2
Circuit Descdption 3-2
Alignment Procedure
: 3-2
Voltage Tables - Transmit Board (878521) 3-3
PCB Transmit Assembly (878521-*)(palts List) ; 3-7
Receive Board 3-9
Circuit Descdption (PCB 70714000) 3-9
Circuit Descdption (PCB 750309)) 3-9
Alignment Procedure 3-10
Receive Board (70714000) 3-10
Equipment Required 3-10
Receive Board (750309) 3-11
Equipment Required 3-11
Voltage Tables - Receive Board (70714000) 3-14
Voltage Tables - Receive Board (750309) 3-15
PCB Receive Assembly 878522* (Parts List) 3-21
PCB Receive Assembly 878662* (Parts List) 3-24
Audio Board
, :: 3-27
Audio Board Circuit Description 3-27
Receive Expanders 3-27
MicrophoneAmplifier 3-27
Auxiliary Input Amplifier 3-27
Intercom Driver 3-27
Intercom Input. 3-28
Headset and Speaker Amplifiers 3-28
Transmit'Mixer and Filter 3-28
Auxiliary Output· 3-28
Remote Transmit Circuit 3-28
Power Supply 3-28
Alignment Procedure 3-29
Equipment Required 3-29
-i-