Barrett 950 - Barrett 900 Series Technical Descriptions; Microprocessor PCB Functionality; RF;Audio and PA PCB Details

5.7 Fault diagnosis.. ............ ............ ............ ............ ............ ............ ............ ............ ............32
5.7.1 General ............ ............ ............ ............ ............ ............ ............ ............ ............32
5.7.2 Transceiver will not power up ...... ............ ............ ............ ............ ............ ............33
5.7.3 Transceiver will not receive but displays OK .......... ............ ............ ............ ............35
5.7.3.1 No receiver noise at all ... ............ ............ ............ ............ ............ ............35
5.7.3.2 Receive noise present, but does not receive.......... ............ ............ ............35
5.7.3.4 Transceiver turns on but displays "Barrett 900 Transceiver" only. .... ............35
5.7.4 Transceiver turns on, internal voltages are normal, but no LCD display......... ............36
5.7.5 Main microprocessor faults ......... ............ ............ ............ ............ ............ ............36
5.7.6 VCO faults ........ ............ ............ ............ ............ ............ ............ ............ ............37
5.7.7 Transmitter faulty ........... ............ ............ ............ ............ ............ ............ ............37
5.7.8 Replacement of PA output and driver transistors ... ............ ............ ............ ............38
5.8 Adjustments...... ............ ............ ............ ............ ............ ............ ............ ............ ............40
5.8.1 Front panel........ ............ ............ ............ ............ ............ ............ ............ ............40
5.8.2 Microprocessor PCB...... ............ ............ ............ ............ ............ ............ ............40
5.8.2.1 Reference oscillator setup (Standard oscillator) .... ............ ............ ............40
5.8.2.2 Reference oscillator setup (High stability oscillator)............ ............ ............40
5.8.2.3 VCO frequency adjustment ......... ............ ............ ............ ............ ............40
5.8.2.4 Carrier Insertion oscillator peaking........... ............ ............ ............ ............40
5.8.2.5 VCO Low pass filter........ ............ ............ ............ ............ ............ ............40
5.8.2.6 DAC Low pass filter ........ ............ ............ ............ ............ ............ ............41
5.8.3 RF/ Audio PCB.. ............ ............ ............ ............ ............ ............ ............ ............41
5.8.3.1 Input low pass filter......... ............ ............ ............ ............ ............ ............41
5.8.3.2 45MHz IF Filter.. ............ ............ ............ ............ ............ ............ ............41
5.8.3.3 IF Inductors....... ............ ............ ............ ............ ............ ............ ............42
5.8.3.4 Noise blanker potentiometer ....... ............ ............ ............ ............ ............42
5.8.3.5 Carrier rejection potentiometer.... ............ ............ ............ ............ ............42
5.8.3.6 Transmit drive level set potentiometer ...... ............ ............ ............ ............42
5.8.3.7 455Khz IF ......... ............ ............ ............ ............ ............ ............ ............42
5.8.4 PA PCB ............ ............ ............ ............ ............ ............ ............ ............ ............42
5.8.4.1 Driver bias setup ............ ............ ............ ............ ............ ............ ............42
5.8.4.2 PA bias setup .... ............ ............ ............ ............ ............ ............ ............42
5.8.4.3 Power level adjustment .. ............ ............ ............ ............ ............ ............43
5.3.4.4 Programmable links ....... ............ ............ ............ ............ ............ ............43
6.0 Software programming and options ......... ............ ............ ............ ............ ............ ............ ............44
6.1 Barrett 930 transceivers . ............ ............ ............ ............ ............ ............ ............ ............44
6.2 Barrett 940 transceivers . ............ ............ ............ ............ ............ ............ ............ ............44
6.3 Barrett 950 transceivers . ............ ............ ............ ............ ............ ............ ............ ............44
6.4 Barrett 980 transceivers . ............ ............ ............ ............ ............ ............ ............ ............44
7.0 Internal jumper settings ............ ............ ............ ............ ............ ............ ............ ............ ............45
7.1 Standard jumpers locations........ ............ ............ ............ ............ ............ ............ ............45
7.2 Configuring antenna connectors . ............ ............ ............ ............ ............ ............ ............45
8.0 Internal options ............ ............ ............ ............ ............ ............ ............ ............ ............ ............46
8.1 Internal scrambler option ............ ............ ............ ............ ............ ............ ............ ............46
8.2 Internal GPS receiver option ....... ............ ............ ............ ............ ............ ............ ............48
8.3 Internal ALE option P/N BCA95001 and BCA95002 ........... ............ ............ ............ ............48
9.0 Features and configurations unique to transceiver models . ............ ............ ............ ............ ............49
9.1 Barrett 950 transceivers fitted with high stability option - P/N BC95001 and BC95003 ............49
9.2 Barrett 950M transceiver module - P/N BC95004 .. ............ ............ ............ ............ ............49
9.3 Barrett 950MR receivers ............ ............ ............ ............ ............ ............ ............ ............49
9.4 Barrett 940 man-pack..... ............ ............ ............ ............ ............ ............ ............ ............50
9.4.1 940 ancillary components ........... ............ ............ ............ ............ ............ ............50
9.4.1.1 110 to 240 VAC input charger supply Barrett P/N BCA94012 ........... ............50
9.4.1.2 Charge regulator suit 13Ah NiMH battery 12V DC input P/N BCA94021 ...50
9.4.1.3 940 multiple-use distribution unit Barrett P/N BCA94010.... ............ ............51
9.4.1.4 940 automatic antenna tuner....... ............ ............ ............ ............ ............51
9.5 Barrett 980 GMDSS transceiver .. ............ ............ ............ ............ ............ ............ ............52
PAGE 3
BARRETT 900 SERIES TRANSCEIVERS