17-10-2016, 09:24 AM
Thanks for further clarification. Also, I had got it in my head that 1 Volt was applied, not 0.5, so I may not need to clean the switch after all! I have just tested the EF91 that got the white hot anode (In my home-made valve tester) and it is still perfectly OK as far as my humble tester is concerned!
Bob
Bob







