[Heathkit] one more DX-100 question

[Bob Young]

What is the clamp control? Is it the bias for the 6146's? I can't find it on 
the schematic. The reason I ask is that I just had a scare. I got the plate 
voltage going fine on 116Vac line voltage and the next step said to adjust 
the clamp until the meter just touches zero, well evidently I turned it too 
far because lights out! It took me a half an hour of checking transformers' 
primaries, secondaries etc, to remember that my variac is fused @ 2 amps, 
that solved that problem thank God. But now how much do I turn the clamp and 
what is it? The clamp was already at zero on the meter, I should have 
brought it back to fully counterclockwise as it says in the manual (or left 
it alone) and then set it, when in doubt follow directions I guess,

Bob Young
KB1OKL