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Starting on the HP200CD oscilaltor
#31

Alan, yes I could do that.
I unfortunately do not know anyone aroiund here who is in the same hobby, let alone with 539 Hickok (which I thought of buying before they went up in price from 700+ top 1,500 and up recently when someone sold one from a NASA lab on eBay about 2 years ago and then it just went carzy from there).

Somehow from the HP manual I read that not even new tubes that are considered within spec are necessarily good for use in HP oscilaltors, as they always say there taht when replacing tubes do this and that and measure the THD and see if the new tube is good enough.
They also recommend once a year total check to see if the oscilaltor is within spec and most often then not it seems that a tube will be a culprit if anything drifts away.




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