My 163 has a very odd habit. Whenever I test a twin triode (ECC3x,ECC8x) the second triode almost invariably reads lower than the first (Ia and Gm) usually by about 10-15%. One would think there would be a 50/50 distribution of first and second triodes reading lower (if at all).
Any ideas ?
M
Any ideas ?
M
What are the tolerances of the parts used in the tester? Older gear often has +/-10 % tolerance resistors (indicated by a silver band at one end). That would explain why there seems to be a systematic offset in the tester.
If you have a tube socket handy, you could try measuring the same triode in position 'A' and 'B' on the tester. That should yield the same results. If it doesn't, I'd look for component variability, switch point corrosion, cold solder joints, etc.
~Tom
If you have a tube socket handy, you could try measuring the same triode in position 'A' and 'B' on the tester. That should yield the same results. If it doesn't, I'd look for component variability, switch point corrosion, cold solder joints, etc.
~Tom
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