I was looking for 105VDC.

Yes, you want 105V at the output but you need to know what the voltage will be after the rectifier, at the first smoothing cap. Then you can calculate the drop you'll need to get your 105V (use Ohms Law again, drop voltage/0.55mA, to find the total R).

Rectifier relationships are good to know: http://www.davidbridgen.com/rects.htm

With a bridge rectifier you are going to have a DC of approx 1.4 times the RMS voltage at the secondary, so ... ?

OK, so here's what I have so far...

Using a choke input filter for the filament/bias supply, given a PT secondary of 12VAC and a filament current draw of 200mA, after the choke I should have 10.8VDC and the current draw should now be 188mA.

Using a capacitor input filter for the HT supply, given a PT secondary of 160VAC and a current draw of .55mA, after the first capacitor I should have 225.6VDC, and a current draw of 0.34mA.

Is this correct?

If so, what's the best way to drop 120 volts to get to the final 105V supply? High resistor values in the pi filters? A simple voltage divider or series resistor at the end? It seems that 360K of total series resistance would drop that much, but I don't know if that's the right way to go. Something tells me "probably not."

Thanks again. I'm ready to attack it again. My "step back" was short-lived. I want to learn and get this thing.