[Heathkit] DX-60B HV DC Output

[Mark K3MSB]

Hi Everyone

I have my DX-60B putting out 50W on 80M with T9 tone (XTAL).

I had the usual issues to attend to with the radio being the first kit
built by the builder in 1972 (I'm the 2nd owner) and it being modified for
a home brew VFO (I've reversed those modifications as I plan to use an
HG-10B – or VF-1 appropriately modified....).

I need a sanity check on some things as I've never owned a DX-60B.

The schematics show plate voltage of 720V for the modulator tube which
should be about the same for the 6146 plate.

At the HV filter output, I'm seeing about 610V key up and 550 key down.

On the 6146 plate I'm seeing 580 Key Down Up and 530 Key Down.

So,  530 Ep x 0.15A Ip x 70% = 56W,  and I'm getting 50W output.    Grid
drive is 2.5 mA.  OK, that's seems in order.

What concerns me is the HV filter output.   The HV transformer secondary
output is 247 VAC.    That goes into a multiplier and then a capacitor
input filter.   I would expect the HV DC output to be

247 x 2 x 1.414 = 695V key up at the HV capacitor output.   I'm seeing 610V.

Now, I still have some strange readings on the bias line, but even so I
should still be seeing closer to 695V on the HV output and I'm seeing 610.

What are others seeing for their Ep ?

BTW,  one big issue I was fighting all weekend was REALLY bizarre bias
readings that resulted in a CW resting current of 150 mA !!    That was my
own stupid fault.   When I replaced the 10 ohm resistor in the bias
circuit,  I used a 10K resistor....    that'll do it....    I'm now seeing
the expected 20 mA or so key up plate resting current in CW.

Other info.... all out of tolerance resistors replaced;  all electrolytics
replaced.   All measurements made with a VTVM.

73 Mark K3MSB