[R-390] Another R-390A Carrier Meter Question

[Miles B. Anderson]

The easiest way to hook up a "real" S-Meter for an R-390A or any other
receiver for that matter is just to pick up the AVC bus and meter it with a
very high impedance (preferably 10 Meg) meter. I did this with a GRR-5 and
homebrewed a meter amplifier with an FET. It's even easier with an R-390
because the AVC voltage is available at the Diode Load pin on the back panel
(or the front panel pin jack if it's a Navy modified unit). If you don't
want to compromise your principles, you can build a genuine hollow state
meter amplifier (VTVM) with a 12AU7 12AT7 or any other dual triode. Just see
look at the print for a Heathkit or EICO VTVM or any tube era ARRL Handbook.

Miles, K2CBY