[R-390] R-390A B+ current drain

[Henry Meils]

I inserted a mA meter into the B+ line at L106:

The only item I could find via Google states that the R-390A draws about 100 ma - my own test show a max. of about 180 mA (Calibrate Mode, BFO on, RF on max. and a min. of about 59 mA in Standby mode (80 mA in Stdby with BFO on)- but with both output AF tubes removed).
Normal operation, BFO on, runs from 130mA to 160mA: RF gain resp. min & max.(all tubes in place)

The two 6AK6 AF output tubes draw resp. 20 & 30 mA: I haven't measured grid bias V yet but plate current indicates normal operation. The two 1st stage AF tubes do not warm up noticeably.
I checked to see if L106 might have shorted turns - inserted a 2nd outboard choke in series with L106 also warms up to roughly the same temp as L106.
I don't like the fact that the entire AF module chassis warms up but it is not due to excessive plate/SG current drain - there are no overheated components (R) in the module so I suppose this is how it is supposed to be but what do others here experience ?

I intend to remove all modules and individual tubes, one by one, in order to make a complete current-drain chart. It's just simple arithmatic, measuring B+ current drains at all stages.

Has any one on this thread made similar measurements, particularly total B+ current drain, max/min ?

Have fun.

Henry - OZ1UF, Cph, DK