17-10-2016, 08:39 AM
Lawrence, thanks for the link. I downloaded it in a few seconds! 
It is interesting to see that the settings for the valve tester are considerably lower than the actual valve specs from the data book. That would account for my white hot anode when set to the correct voltages that were, in fact, way too high. It will be ineteresting to check the valve to see if it still works, because the anode was quite a brilliant white for a second or two before I turned the tester off!
Maybe there is nothing wrong with it after all, and the designers were aware that the volts should be set a lot lower than specified. I will clean the test switch contacts before putting it together again and testing it with the "real" test volts! Fortunately, I have a very large number of EF91s, so the probable destruction on one is of no consequence.
I have heard it suggested that millions of years in the future when the earth is a dying planet, dimly illuminated by a dying sun, and totally bereft of water and life, human or animal, there will still be a sprinkling of EF91s lying in the dried-out wastelands!
Bob
It is interesting to see that the settings for the valve tester are considerably lower than the actual valve specs from the data book. That would account for my white hot anode when set to the correct voltages that were, in fact, way too high. It will be ineteresting to check the valve to see if it still works, because the anode was quite a brilliant white for a second or two before I turned the tester off!Maybe there is nothing wrong with it after all, and the designers were aware that the volts should be set a lot lower than specified. I will clean the test switch contacts before putting it together again and testing it with the "real" test volts! Fortunately, I have a very large number of EF91s, so the probable destruction on one is of no consequence.
I have heard it suggested that millions of years in the future when the earth is a dying planet, dimly illuminated by a dying sun, and totally bereft of water and life, human or animal, there will still be a sprinkling of EF91s lying in the dried-out wastelands!
Bob
