There's the double whammy of the low side LO, from 9068kHz to 9168kHz
through the 17m band, being injected into the mixer at 13dBm and then
leaking sidebands into the IF. Nothing like having a -20dBm signal
just a 100kHz away from the IF.
It is possible (just, IMHO) to change the crystal to high side and
fiddle with the tuning in the output of the LO mixer to get high side
injection. As Gerry says then you have to use the reverse sideband to
get USB.
You can see this was a radio that was designed to be an old
"harmonic" band radio with a hack for the WARC bands. They did fix
this on later rigs. Still a good radio though (I have one!).
On Nov 9, 2007, at 6:44 PM, Dr. Gerald N. Johnson wrote:
yah, low side LO injection with a 9 MHz IF gets twice the LO (9 x 2
= 18
MHz) through the mixer at least as strong as the desired signal but it
puts USB as the normal side band. Later radios use high side injection
with the LO up at 27 MHz and only the 2nd harmonic of the IF leaks
through but its weaker. The rub is that USB is the opposite from
normal
sideband that way.
73, Jerry, K0CQ
in response to
I used to own one and always referred to it as the Omni C. Although
the Omni C was the first Ten-Tec to feature the new WARC bands,
many people, like myself, discovered that the 17 meter band emitted
some spurs because of the IF frequency. I understand the IF scheme
was later changed in the Delta and Corsair to eliminate the problem.
73, Winston K4CWQ
--
73 DE N7WIM / G8UDP
Kevin Purcell
kevinpurcell@pobox.com
BIRRGRMP BRU ROTARY GE GE UGERUMF OM WITH MY SET RETTYSNITCH SPITTY
TONE HIT IN POTIMUS? BK
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