[R-390] PTO Woes

[Dennis L. Wade]

Hello all,

	I think I killed my PTO.

	Probable cause of death was excessive pressure on the shaft while 
attempting to re-install the RF deck after cleaning and recapping. 
Apparently the Oldham coupler wasn't aligned as I had thought, and after 
the deck was installed, I turned the Kc/s knob and noted an excessive 
amount of drag.  Upon inspection, the mis-aligned disk was *tightly* up 
against the VFO shaft.  Next time I have to take out the RF deck, the 
PTO is coming out first.  Ah, the wisdom of hindsight.

	Looking at the output on a counter, it wasn't near 2.45500 Mc/s.  (It 
was over 3).  Turning the shaft clockwise brought the frequency *up*! 
Running the shaft the other direction brought it down to around 3..then 
back up..then down consistently in the manner it should.

	My layman's hunch says the corrector stack and/or the core itself it 
toast.  I've never done it that I know of, but it almost acts like it 
was run out beyond its 10 turn stop given its symptoms.  If I set it now 
at 2.455, and call that turn 0, it behaves ok till about turn 6 or 7 
when the frequency goes amuck, jumping around hitting almost 6 mc and 
then, around turn 8 settles back approximately the right frequency. 
However, it reaches 3.455 mc/s in about 9.5 to 9.75 turns.

	I'm not up to rebuilding a PTO (See what happened when I took out the 
RF deck?). Unless I decide to do an autopsy, I have available a Motorola 
for someone who would like one to rebuild. :/

	Maybe someone would like to rebuild mine? :D

	Anybody have a good PTO available?  I'd like one with linearity screws 
(as in the Cosmos) if possible.  I'd like to find one here, but failing 
that...anyone have any experience with the "as-is" PTOs from Fair?

	Also, please advise appropriate penance for killing a PTO.

               Thanks,

                Dennis

Dennis Wade
KG6ZI
Carmichael, CA