[TenTec] Omni 6+ v. Corsair

[Dr. Gerald N. Johnson]

On Thu, 2006-07-27 at 11:29 -0400, Craig Roberts wrote:
> Please pardon me if this is an "apples and oranges" question, but, how 
> would you compare the Corsair with the Omni 6+ in operation?  Is there a 
> significant difference in performance? 
> 
> I have a Corsair and am generally very happy with it.  In fact, the only 
> significant complaint I have is about its instability before warm up 
> (though, as PTO solid state rigs go, it's certainly better than my Drake 
> TR-7 was).  I do like to run digital modes, so I'm guessing the Omni 
> might be better suited to that, too.  I'm just wondering if the extra 
> bucks invested in the Omni 6+ would buy me a significant step up?
> 
> My Pegasus will stay, by the way.  I consider it nothing more nor less 
> than the coolest computer peripheral ever.
> 
> 73,
> 
> Craig
> W3CRR

Omni VI+ will have better LO stability.

Warm up stability might be improved by tightening up the PTO drive with
a new cup and bearings or another end load washer on the back end of the
shaft.

The Omni has what I consider an annoying characteristic. While listening
on USB when switching to CW on the same frequency (quite common on VHF)
it shifts to LSB which makes it hard to copy the USB signal I just was
listening to preparing to call (very weak) on CW. I had planned to use
my Tentec with transverters for VHF and up and that staying on frequency
is important to me so I bought a Corsair II, not an Omni.

The Omni RF and first IF stage uses 4 JFETs in parallel grounded gate. A
sturdy stage, far easier to build than the transformer feed back bipolar
stages use in the Corsair II. The Corsair circuit (from Anzak, hence a
potential patent problem) is Ulrich Rohde's favorite, he doesn't admit
the grounded gate circuit with a gaggle of ordinary JFETs is as good
though there was a more powerful TI JFET he admits works.

-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer