Picked up a bunch of valve testers on the weekend - A VCM163 and some
old AVOMk1 and Mk2 dungers. Got to like the VCM163 real fast, and was
reminded of what I hate about the previous models - that awful fiddly
backing off setup to find the Gm. Studying the manuals that came with
these things, it occurred to me that the only real difference between
good and bad models is the oscillator/detector arrangement on the 163
(and the extra meter). Would it be a worthwhile project to make a
retrofit osc/det board to plumb into old sytle AVOs, to upgrade them.
The second meter could be emulated by a push button, so one could
flick between plate current and Gm on the existing meter.
M

"mike diack" wrote in message
...
Picked up a bunch of valve testers on the weekend - A VCM163 and some
old AVOMk1 and Mk2 dungers. Got to like the VCM163 real fast, and was
reminded of what I hate about the previous models - that awful fiddly
backing off setup to find the Gm. Studying the manuals that came with
these things, it occurred to me that the only real difference between
good and bad models is the oscillator/detector arrangement on the 163
(and the extra meter). Would it be a worthwhile project to make a
retrofit osc/det board to plumb into old sytle AVOs, to upgrade them.
The second meter could be emulated by a push button, so one could
flick between plate current and Gm on the existing meter.

Not at the prices they fetch in original condition...
cb