Widowmaker errr I mean Footwarmer linear amplifier living up to its name.

Описание: Footwarmer linear amplifier that goes by a few more names. It's nickname is widowmaker because of the dangerous transformer less design. This one is two tube and I have seen very similar 3 tube versions too. All outputs, turbocharged, low drive. The new Blue Palomar Skipper 300 from the 2000's, not the old Palomar's from the 1980's era, is another transformerless amp. I also have seen versions of this that had a filament transformer for the low voltage and filaments, and some like this one with no transformer at all. All that I have seen are Tetrode (Turbocharged) amps and do a lot of swinging.
This Widowmaker errr Footwarmer came with 2 tubes, 30KD6 tubes but one was busted. It uses the 2 30v filament tubes in series, plus a dropping resistor and then the low voltage circuitry getting the voltage off the ac mains. It does the same for the HV using a voltage quadrupolar circuit coming off the mains. When they work, they work great as transformerless eliminates transformer voltage drop. Problem is, when it goes bad, there is no transformer safety net.
So, this one has been recapped, diodes tested, new tube installed, and slowly variac'ed up. With the meter connected to the HV and ground, I was getting 120ac out of it. Hence, I started shutting stuff off. The variac down to 0, variac off, inline wattmeter off, then amp off. Guess what? Still reading 120v ac on the HV line even with all that off. Something is seriously wrong. I don't know what yet, but this is why they call these kinds of amps the Widowmaker. I will get a line isolation transformer before I play with this one again.