Eico 232 VTVM Schematic - Printable Version
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Eico 232 VTVM Schematic - RodB - 02-05-2025
A friend gave me this Eico 232 VTVM and I'm having trouble locating the schematic for it. This one seems to be a later version because it has solid state diodes to replace the 6AL5 duo diode tube. I would say maybe early 60s. All my searches have resulted in the schematic for a 12AU7 and 6AL5 configuration. This one has only a 6FQ7/6CG7 replacing the 12AU7. Any help is appreciated.
RE: Eico 232 VTVM Schematic - morzh - 02-05-2025
Is that a battery holder?
RE: Eico 232 VTVM Schematic - Chas - 02-05-2025
Try BAMA for a schematic.
Looks like a replacement power source for the D battery has been installed. The tube may be a sub for the 12AU7. As long as it balances and is stable should be fine.
Was the Uniprobe provided?
Chas
RE: Eico 232 VTVM Schematic - RodB - 02-05-2025
It's a microwave antenna. ?;-p?. I substituted 1N4002s off the 6.3 vac winding for the 1.5 volt battery. Uniprobe is there. BAMA has the older schematic. I haven't looked up the tube yet, it has two sections but it's a 6 volt tube. I guess I'll wing it for now.
RE: Eico 232 VTVM Schematic - Trog1058 - 12-25-2025
I have both battery and tube replacement modes
attached are the manuals
RE: Eico 232 VTVM Schematic - Joe Rossi - 12-26-2025
Looks like someone put the 6FQ7 in because it fit?
RE: Eico 232 VTVM Schematic - RodB - 12-26-2025
I don't have it open but as I remember, the 6AL5 tube socket is missing and replaced with two diodes. The 6FQ7 twin triode looks like a good replacement for the 12AU7. The docs provided earlier are not matching this version as they have a different meter movement and the 6AL5 tube.
RE: Eico 232 VTVM Schematic - TV MAN - 12-26-2025
6FQ7 is a common replacement. Probably owned by a TV guy and those were very common TV tubes. I think I even have a note on my Eico sig gen that says a 6CG7 will help the performance, but never did the swap. I think I have the twin to yours and if I can easily find it, I can take a look inside and see what is glowing.