Re: Marconi 702 advice
A test of the MHD4 on a different tester shows an intermittent heater cathode short.
I thus need a new one. However, if vertical and not bumped it is OK, so that's
not the cause of the problem. That's why the first tester didn't find it.
In any case a grounded cathode would
increase gain, not ruin it. Putting 4 volts AC on the cathode
would result in an enormous hum and might blow the cathode electrolytic
bypass.
I suppose I could temproraily bodge in a 4AV6 which would be the "usual suspect"
American electrical equivalent and would work perfectly. Luckily these are cheap
as water because nobody used them.
Last edited by dtvmcdonald; 18th May 2017 at 2:52 pm.
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