[TenTec] Omni V controls and Corsair II

Dr. Gerald N. Johnson, P.E. geraldj@ames.net
Sat, 19 Sep 1998 20:25:13 -0500


I took the time this afternoon to compare an Omni V and a Corsair on the
same antenna (A-B switch) on both SSB and CW. The Omni V performed
slightly better on weak signals but it was very close. However I ran
into a couple things that would bug me beyond use. Those are that CW is
received on LSB, and the dial display stays the same while the actual
received frequency changes when modes are changed. My serious use for
such a radio is with transverters for VHF. Around here (about 15 miles
from the Boondocks), you never know whether the next signal you hear is
going to be on CW or SSB and my experiences with a couple Yeasu VHF/UHF
multimodes that shift the frequency similarly has not been good. I've
lost a significant number of potential contacts by hearing only the tail
end of a CQ and then having to change mode and repair the stupid
shift... which I rarely do correctly. So is there a way to make the
display change, not the receive frequency when changing modes? Is there
a way to make the Omni V work CW on USB instead of LSB? What is
happening is that the receiver display remains the same while the
display meaning changes from SSB carrier frequency to CW transmitted
frequency.

With its mechanically driven PTO, the Corsair II only changed display
frequency when changing sidebands. But this particular Corsair II seemed
to have another problem. It had a large noise level, as indicated by the
background noise on 20m showing about S-7. Signal to noise was very
comparable to the Omni V, just a hair poorer despite that noise. With
antenna disconnected the S-meter fell to zero. My guess is that there is
an instability in the front end or a noisy input PIN diode or PIN diode
driver. Or is this normal with the Corsair II?

Right now the lack of frequency changes between USB and CW makes me lean
toward the Corsair II. I'd have to modify it to get a safe low level
output for transverters but that doesn't look to be difficult looking at
the manual.

I think I've seen some alternative source controller chips for TenTec
radios? Which were they for and what do they change? Or was that for
some other brand of radio?

73, Jerry, K0CQ

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