Possible Electronic Defects* with SWR-TR Circuit Board 80450
*SWR Metering/ Power Output; Suspect D1
*Modulation ALC; Suspect D2
*Antenna Relay Inoperative; Suspect D3
*Insensitive Receiver; Suspect D4 and/or D5
One or more of the above issues tend to occur whenever the transmitter is loaded into a mismatched antenna with high standing wave ratio (SWR). The most common problem is a short-circuited diode D1 and/or D2.
Rather than expending time in determining specific defects, the author suggests replacing all five diodes. Be careful to install the diodes with the cathode band oriented correctly.
Place an indelible marker "dot" on the printed circuit board at the banded cathode end of all five diodes before removal.
Reference Documentation
Ten-Tec Omni-D Series-C Transceiver
SWR-TR Board
Ten-Tec P/N 80450
Manual Pages 3-52 and 3-53
Ten-Tec Omni-D Series-C Transceiver
SWR-TR Board
Ten-Tec P/N 80450
Manual Pages 3-52 and 3-53
Printed Circuit Board Repair
Replace all diodes on the SWR-TR Board
Diodes, D1, D2, D3, D4 & D5
Ten-Tec P/N 28001
Generic P/N 1N4148 / 1N914 Silicon
Replace all diodes on the SWR-TR Board
Diodes, D1, D2, D3, D4 & D5
Ten-Tec P/N 28001
Generic P/N 1N4148 / 1N914 Silicon
