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Old 3rd Jun 2020, 8:26 pm   #1
AdrianH
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Join Date: Mar 2020
Location: Blackburn with Darwen, Lancashire, UK.
Posts: 1,567
Default Yes, yet another home made valve tester.

Not too sure how useful this will be for testing valves but it is occupying time whilst building.

Fitted two meters today, some 4 mm sockets and a few switches.

Red ones on left hand side for heater/filament.
Black same side for Grid.

To the right side two reds for anode and g2 and two blacks for Cathode & g3.

There is not enough space in the chassis for a power supply so I am going to fit the buck style PSU's into a metal box to provide a bit more heat-sinking and a couple of pots to set HT and heater volts, I have yet to sort a linear pot to set a negative Grid bias.

There is no plan to this, I never seem to make any as it is always down to what I can find in my bits and bobs boxes or what I can fabricate as I go along.

One HT output has the 4 or 40mA meter in series so by changing leads I should be able to either check g2 or anode current. Changing grid bias +/- 0.5Volt from spec, I hope should allow me to figure gm.

I am sure there are other things I can do with it, but it is a start. Got to make up the jumper leads as well.

Adrian
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