[R-390] Collins R 389 PTO

[Tim Shoppa]

Gord asks:
> Do I get burned at the stake for this suggestion?

I'm not sure why we go to so much trouble to replace a good
solid PTO :-).

I've homebrewd VFO's using variable capacitors with reduction drives
and dials, and they work, but they are not the joy that a good
PTO gives.

I've also homebrewed PTO's and their pure simplicity and reasonable
tuning rates with just pennies of hardware are amazing. KD1JV's
PTO in his $50 40M SSB transceiver is a thing of pure genius, I've
built it many times over and enjoy tuning it every time.

QST in the 60's had at least one article about a linear-tuning
homebrew PTO, made out of a junkbox ferrite core and a very
carefully wound and measured coil.

I was looking at an old (meaning 50 year old) QST today at a
review of the Cosmophone transceiver. It had a beautiful set
of two independent VFO's, which I always assumed from the
fact it was made by Cosmos would be PTO's. Despite that, the
review concentrated entirely on the tube lineups and completely
ignored the beautiful front panel and tuning knob mechanics.

My single solid state rig at home, my Ten Tec Triton IV, uses
a nice little, mostly plastic innards PTO that has never given
me any trouble.

Tim N3QE