[R-390] R390 Posts HT Dropper, HT AC regulator

[Bill Hawkins]

Polished? We don't care about your nationality!
Grist? Illigitimus non carborundum! Don't let the baastards
grind you down. Otherwise, no worries, mate.

(That's what the guy at the front desk said when we got back from
visiting the return of the Fairy Penguins in a downpour and found
that half the power in the room was out, including the bathroom.
Healsville in a 60 MPH breeze made up for everything.)

Depth of mechanical and radio engineering know-how? Nay, it is
the peak of that vacuum tube knowledge that you behold.

The idea to put a dropping resistor between the HV CT and ground
is interesting, but it does stress the HV insulation.

Concerning mod mania, consider that the Collins engineers were the
best around at the time. See the Engineering Report. Tube design
improved a bit after the R390 was engineered, but not a lot.

Do not assume that tighter regulation will make your set better.
Go back and read Freud on the subject of anal-retentive control.
What makes your set better is proper lubrication and alignment.

If you try to measure sensitivity, be sure that your signal
generator is very well shielded. Your first clue that something
is wrong is when lower steps on the attenuator don't seem to make
any difference.

Smile, mate. Nothing serious here.

Best regards,
Bill Hawkins, who will never forget our trip down under from Minneapolis, MN