Loudenboomer Mark II A

[WA7KKP]

edited

If the swinging choke L1 (4-16 Hy) developed a winding short the voltage should jump up even higher than 3500V and probably start blowing things up like filter capacitor C1 which is only rated 3000V.

I've seen that happen several times in commercial HV power supplies, and I'd bet my paycheck that's the problem. Finding another input choke can be problematic these days . . . most SSB amps now just have a big bank of filter caps, 'cuz chokes are expensive . . .

Gary WA7KKP

[N5AD]

Ok, been a few days, and I thought I would post my final update. Upon further inspection, I found that the filament voltage was high at 5.76v. So, I surmised that the real culprit here was that the overall supply voltage was high. I measured 125.6v at the wall socket. The manual references 115v. It has been mentioned on here that that could be an issue. So, I ran the figures and it seems that dropping the voltage on the whole amplifier system(power supply et al.) by about 12v would give me the voltage to bring everything back into specification according to manual. I was intrigued by the mention of a bucking transformer, and not knowing what that was, did some research on it. Turns out that it is a very common solution for a variety of circumstances. I ordered a commercial version, got it installed and voila, things are purring along nicely. I truly appreciate all the positive feedback, suggestions, and troubleshooting from the knowledgeable folks here on this forum. Thanks to all.

[WB2WIK]

I've seen that happen several times in commercial HV power supplies, and I'd bet my paycheck that's the problem. Finding another input choke can be problematic these days . . . most SSB amps now just have a big bank of filter caps, 'cuz chokes are expensive . . .

Gary WA7KKP

Seems that wasn't the problem, he just had high line voltage on an old amplifier.

Chokes were used with 866As (the original rectifier system) because they needed to be.

[KH2G]

Just because I like going for the easy things first, I would check the mains input voltage first. (while I'm at it, I might as well make sure my filament voltage is correct to enhance my tube life. After that, you've been given many good suggestions.
You'll get it and try to remember the "One hand in the pocket rule" when dealing HV
Have fun
Dick