I now have enough hours on the repair job on the amp to proclaim a modest victory. It has been going an hour at a time for a week now with nary a burp so I finally am convinced of its successful repair. The culprit was a failing vacuum relay in the output circuit, certainly the most logical choice due to wear and tear but also the most expensive. Since the likely reason was hot switching due to QSK board issues, I chose to work my way through the QSK board as most parts there were over twenty years old. At least now I am confident of the newly installed parts and again a used (pull) vacuum relay. The difference this time is that I am using a K1EL Keyer (Winkeyer USB) which affords me the ability to switch a PTT line to the amp at a predictable and programmable time prior to the key line activating the transceiver such that no hot switching ever occurs. The natural downside of this is that my amp is no longer QSK. That loss of feature is a little bothersome but not so much as to get me to change vacuum relay’s like fuses.
Today I am alone with two 4 year old granddaughters. I hear nothing from them just now and that cannot be a good thing. I better go see what walls are falling.
Thanks for reading my Blog. Best, Chas W5PG