[Elecraft] KPA500 T/R Switch Board – D8 Identification

[Andy Durbin]

My notes on TR switch R7 include - "Several reports of R7 failure some also with failure of D8 and D9. Results in approx 20 dB RX signal attenuation when BYP compared to OPER."

The voltage of almost every component junction in the TR switch were researched and documented here - https://www.qsl.net/wb4kdi/Elecraft/KPA_TR.html

Click on the schematic links for the two TR switch states.

More info on KPA500 at the parent level - https://www.qsl.net/wb4kdi/Elecraft/


This is a great KPA500 resource and is being maintained.  Please contribute if you learn something new.

73,
Andy, k3wyc