Well, I found a nice mil/industrial 5R4WGB tube (with special plastic base that
covers up part of the tube), and also DLed the HX-50 manual from BAMA.

Very helpful to know the bias setting (50-60 mA) and how much cathode current
you dare load up (wow, 180 mA, that's a lot, given that a 6146 tops out at 150
-- however, the plate voltage allegedly drops to 600V).

Also that the little knob under hte PA on the relay compartment really is the
neutralizing cap. Beats reaching between the "hot" finals with a screwdriver,
like in those high-priced Iowa rigs.

Everything seems to work, except no modulation on SSB or AM -- that is, no
increase in RF out or DC in when I zap the mic center pin with a screwdriver,
with the AF gain turned full up. Hope that compactron isn't dead in one
section. Audio circuit should be easy to troubleshoot, especially since that
portion of the BAMA schematic is actually readable (there is a section with the
ghost of a tube just floating in space, with traces of wires and components
around it). If I need a better schematic copy, I'll ask.

Tnx for the discussion so far -- Mike K. AA1UK

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