26-10-2016, 03:42 PM
It isn't rectified at all! It is coming straight from the transformer as shown in the diagram. So why do they describe an ac supply as being either positive or negative? I took the meter movement out again so I could get at the switch. I gave the contacts a real good clean with the finest grade wet & dry paper, and also contact cleaner. Although it seems to be working, it is showing most of my valves as very low. An uused EF80 just got into the green, but not by very much. Despite this, all the valves work in a one valve receiver - all with good volume and low HT (45V).
I am beginning to have doubts about valve testing in general. I have just received my vintage radio components catalogue, and he is offereing ECH35 valves with very low in emmission at 25p each, but saying they work fine in radios! I can beleive it - that has been my experience as well!
Bob
I am beginning to have doubts about valve testing in general. I have just received my vintage radio components catalogue, and he is offereing ECH35 valves with very low in emmission at 25p each, but saying they work fine in radios! I can beleive it - that has been my experience as well!
Bob
