On May 24, 2010, at 7:51 PM, Sam Morgan wrote:
So far I have rebuilt the PTO with the kit from TenTec.
But I found the dial calibration is off by a few kc (2-3)
Even if I try to use the offset maxed to one extreme,
it's not on frequency.
It's a PTO driven radio. It's never on or off frequency, per se. The
PTO produces a signal and that's the frequency the radio is "on". The
display is an approximation of what the PTO is producing and due to
the difference in resolution won't match it exactly anyway. The PTO is
infinitely variable and with a good enough hand can be set to any
frequency in it's range, while the display is limited to the number of
digits it has and the last one is not always correct, as it were.
Bear in mind that this radio is from the day when 14.200 +- 1khz was
"on frequency", not 14.200.000.
The most important question is what happens when you transmit? If the
radio is tuned to a signal at 14.200, where do the signals come out?
If the transmit frequency is correct for ssb and cw, the rig is on
frequency and the display is off. If they are too far off frequency to
be properly received then the radio needs to be adjusted to get them
back on frequency.
Once that is done, if need, you can adjust the display.
I have only the Omni C Operators Manual pdf to go by,
even though I might could figure out what to adjust,
I'm not sure which circuit I should be adjusting first?
Is this a PTO problem or is it somewhere on the other osc boards?
Did you look at the Ten-Tec website under "obsolete manuals"? If your
rig is not there, perhaps someone has one they can scan and send you.
About a year ago TenTec changed their policy from forbidding scanned
manuals to contracting someone on this list to scan them and posting
them on the official website. Since then the head of the amateur
division has left and the scanning has AFAIK stopped, but in the last
month TenTec has officially allowed anyone with an obsolete manual to
scan it and send it to someone and will post it on their website if
sent a copy.
I'm not a really good radio technician,
but I am sure I can have plod along, have fun, and get this done.
what is the sequence to use for alignment?
Any helpful pointers will be gratefully accepted.
If the rig transmits on the same frequency it receives, you can always
do what people did before digital displays, they just picked a good
spot to call CQ and let everyone else match them, or tuned to a
station calling CQ and responded on their frequency whatever it
happend to be.
Just stay away from the band edges. :-)
I don't think anyone will refuse to QSL because your log says 14.241
theirs says 14.23902.
Geoff.
--
geoffrey mendelson N3OWJ/4X1GM
Jerusalem Israel geoffreymendelson@gmail.com
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge
or understanding, as in he has a sub-wikipedia understanding of the
situation. i.e possessing less facts or information than can be found
in the Wikipedia.
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