I'm noticing that the HV from my rebuilt AC-4 is running quite high - on the order of 730VDC. I know that my line voltage is around 126VAC and if I run the AC-4 from an autotransformer, I have to dial that back to approximately 110VAC to see 650VDC output. I find that just a bit odd since the input voltage on the schematic shows 120VAC.
I can reduce that input voltage with either a bucking transformer or I also have a rather heavy-duty transformer with multiple input taps where I can feed my line voltage across the 132VAC connection points and have 110VAC at the 115VAC tap.
I'm just wondering why an increase of 6VAC from the original spec has the output voltage so high and whether that increase is detrimental. I realize the filament voltages are probably on the high side as well (I haven't checked those) but that may be harder on the tubes than the HV increase but I don't know that for sure.
Any thoughts?
Thanks,
Barry - N4BUQ
