[R-390] Variac Startup for Stored R390

[Jacques Fortin]

Jim, Jerry,

There is no electrolytic capacitors in the power supply of a R-390 (non-A).
Put a voltmeter in the B+ test point of the power supply/audio module wrt to GND to monitor the regulated +180V.
If the value there stabilizes at +180 ± 2V after power on, you are good to go.
If there is too much current drawn by the + 180V line, the output of the regulator will not be able to climb up.
If there is an internal fault in the power supply circuitry, the output can go higher than 250 V.
If this happens, shut the power off and diagnose the circuit.
Last time I seen this type of problem, it was because the filament of V509 gave up.

73, Jacques, VE2JFE in Montreal