I replaced the capacitor bank and nothing else a month or so ago. The meters were doing this before. And you could smell that old capacitor smell so i replaced them. It solved the meter light fluctuations but now the flickering with audio is back. The hv power meter shows fluctuations following voice pattern. Anyone have a idea here? Failing diodes? Tube issue? Heres a quick clip . Im keying 20 or 40w am off and on here.
I have to ask what is it you are keying? Do you have RF drive going in? Is this AM? The reason the bulbs are getting bright is either because the amp is oscillating or you have bad bypass caps or no bypass caps on the HV or on the line voltage to the bulbs. One or the other.
Almost certainly the panel bulbs are illuminating due to failure of one or more of the decoupling capacitors on the filament supply, C22 to C25 . . . just replace all 4. The HT Voltage will obviously dip under load, ie as as you talk on SSB, so the Meter will reflect this. (so it is quite normal) Roger G3YRO
Im not sure. I pulled the tubes and noticed one pin looks funky again. Probably flux from when i had to reflow the solder that dropped out with silverbearing solder
Ill have to find out what they are rated at voltage wise and maybe I have some or order more. That makes sense but who knows
I have a update. It was the tube socket for filament. I pulled the tubes. Cleaned everything. One tube wouldn't light till i cleaned the socket and re compressed the pressure clip . Works good now, no meter light changes now Added the diode protection for the meters while i was in there. Thanks guys
Glad you got it sorted . . . I must admit that I hadn't imagined that the pins on the Valve Base would be that corroded ! Otherwise I would have suggested that first. (I would expect that you're also getting more power now too) Roger G3YRO
The sockets have a second part that applies pressure to the socket halves in there. They get weak. You can re compress the clip and re install it. The socket overheated slightly. Multiple issues caused it. Previous owners soldered the pin with reg low temp solder. Solder dropped out. Pin was resoldered w silver bearing solder but too much flux was left behind. Heated up and coated the pin and socket. So anyway i might just pull the sockets out of my hl2200 and swap or see if i can source new ones.
