
BARRETT 900 SERIES TRANSCEIVERS
4.5
Remote control head
The on/off switch on the volume control potentiometer completes the circuit to ground and activates the
power relay on the PA in the transceiver's main body through the remote control cable via line RH PWR SW.
In addition the on/off switch turns on Q6 al14 V power feed to the regulators U7 and U6. The 5 V
regulator U6 supplies the digital ICs and the second 5 V regulator U7 is stacked on the first to obtain 10 V for
the analogue circuit.
Keyboard encoding is handled by U2, a matrix encoder chip that provides a PWM coded output only when a
key is depressed. The microphone up and down buttons are also handled by U2.The serial output from U2 is
buffered by FET Q8 and emerges at connector P1 as RH SKB OUT for eventual decoding by the
microprocessor.
Serial data from the transceiver's main body is sent to the remote head on line RH SD INB via the remote
head interface cable. This serially coded data is decoded by embedded microprocessor U1 and distributed
in parallel form to either the LCD or mode and status LED's as required. LCD contrast is temperature
compensated by thermistor TH1. Q1 switches the LCD and keypad back-lighting on and off by computer
control.
PAGE 28
Содержание 900 Series
Страница 58: ...BARRETT 900 SERIES TRANSCEIVERS RF Audio PCB overlay showing optional narrow filter components PAGE 58 ...
Страница 60: ...BARRETT 900 SERIES TRANSCEIVERS PAGE 60 This page has been intentionally left blank ...
Страница 72: ...BARRETT 900 SERIES TRANSCEIVERS Microprocessor PCB overlay showing TCXO PAGE 72 ...
Страница 74: ...BARRETT 900 SERIES TRANSCEIVERS PAGE 74 This page has been intentionally left blank ...
Страница 87: ...BARRETT 900 SERIES TRANSCEIVERS PA PCB overlay PAGE 87 ...
Страница 88: ...BARRETT 900 SERIES TRANSCEIVERS PAGE 88 This page has been intentionally left blank ...
Страница 89: ...BARRETT 900 SERIES TRANSCEIVERS PA schematic See File PA SCHEMATIC pdf PAGE 89 ...
Страница 90: ...BARRETT 900 SERIES TRANSCEIVERS PAGE 90 This page has been intentionally left blank ...
Страница 99: ...BARRETT 900 SERIES TRANSCEIVERS Front panel PCB overlay PAGE 99 ...
Страница 100: ...BARRETT 900 SERIES TRANSCEIVERS PAGE 100 Front Panel Schematic 900 Front Panel Schematic Drawing No 900516A1 ...
Страница 103: ...BARRETT 900 SERIES TRANSCEIVERS Remote Control Head PCB overlay PAGE 103 ...
Страница 108: ...BARRETT 900 SERIES TRANSCEIVERS Scrambler PCB overlay PAGE 108 ...
Страница 109: ...BARRETT 900 SERIES TRANSCEIVERS Scrambler Schematic PAGE 109 900 Scrambler Module Schematic 900D54A5 ...
Страница 111: ...BARRETT 900 SERIES TRANSCEIVERS GPS ALE Motherboard Overlay PAGE 111 ...
Страница 112: ...BARRETT 900 SERIES TRANSCEIVERS GPS ALE Motherboard Schematic PAGE 112 900 GPS ALE Schematic ...
Страница 114: ...BARRETT 900 SERIES TRANSCEIVERS 950MR Low Pass Filter Power PCB overlay PAGE 114 ...
Страница 116: ...BARRETT 900 SERIES TRANSCEIVERS PAGE 116 This page has been intentionally left blank ...
Страница 121: ...BARRETT 900 SERIES TRANSCEIVERS 980PSU DC DC Switch Mode Power Supply PCB Overlay PAGE 121 ...
Страница 133: ...BARRETT 900 SERIES TRANSCEIVERS 900 Hand Microphone Schematic PAGE 133 930 940 950 980 Hand Microphone Schematic ...
Страница 134: ...BARRETT 900 SERIES TRANSCEIVERS 900 Cloning Cable Schematic PAGE 134 930 950 980 Cloning Cable Schematic ...
Страница 139: ...940 Front Metalwork Connection PCB Overlay BARRETT 900 SERIES TRANSCEIVERS PAGE 139 ...
Страница 142: ...BARRETT 900 SERIES TRANSCEIVERS 940 Automatic Antenna Tuner PCB Overlay Barrett P N BCA94009 PAGE 142 ...
Страница 148: ...940 Tuner Front Panel PCB Overlay BARRETT 900 SERIES TRANSCEIVERS PAGE 148 ...
Страница 149: ...940 Tuner Front Panel PCB Schematic BARRETT 900 SERIES TRANSCEIVERS PAGE 149 ...
Страница 153: ...BARRETT 900 SERIES TRANSCEIVERS 940 Charge reg 13Ah 12V DC input PCB overlay Barrett P N BCA94021 PAGE 153 ...
Страница 163: ...BARRETT 900 SERIES TRANSCEIVERS PAGE 163 940 Programming Cable Schematic 940 Transceiver Programming Cable Schematic ...