Re: Valve testers and E88CC / ECC88 valves
Peter,
I've tested a number of ECC88s and E88CCs on my two panel AVO and get the same result for both settings 1 and 2 so I don't experience your behaviour even for valves with differing gm values for the two halves. I've no idea what is going on with your set up. Yes it may be instability in yours I suppose. I tried slipping a large ferrite toroid over the valve under test but it made no difference.
Interestingly the Avo version 17 data book lists "no data available" for the ECC88 and the E88CC has the funny little square symbol against it which is something to do with voltage breakdown testing and probably doesn't apply to the two panel Avo. Perhaps Avo knew there was something funny about testing the ECC88 on the two panel.
Ian
|