Andy wrote:
It looks like some of the SM 3-pin diodes D10, D9, etc have failed. I was
only testing with a 100 watts although it was with a very high SWR at the
time

Do I have to go to SGC for the diodes or is there a replacement that I can
use instead?

My SGC-230 manual says those are 1N4148 high speed
switching diodes which are one of the most popular
diodes of all time. They should be readily available
almost anywhere.
--
73, Cecil http://www.w5dxp.com