[TenTec] Omni VI+ BFO

[Paul Christensen]

Tom,

"the SSB signal might not be centered in the filter passband causing 
distortion on the transmitted signal".

That's correct and why a counter should be used -- or in the alternative, 
the BFO can be "leaked" with a simple test lead from the Omni Six and 
measured on a general coverage (GC) receiver, capable of *accurately* tuning 
to a 9 MHz signal.  If you do, then you can first tune the GC receiver to 
WWV at 10 MHz, and note any small frequency error to compensate.  Then tune 
the GC receiver to the Omni's USB, LSB, and CW BFO frequencies and beat them 
against the CW sidetone of the GC receiver, ultimately attaining zero beat. 
Sure, there's a bit of manual labor involved but if you can get that set-up 
to work, it may be worth it to avoid a trip back to TN.

Note that the overall signal is centered in the filter passband -- but the 
BFO frequencies are not.  They're adjusted above or below the upper or lower 
knee of the filter skirt, depending on the selected sideband.

Paul, W9AC

----- Original Message ----- 
From: "Tom Stone" <sail8 at verizon.net>
To: <tsm1 at tmcom.com>; "'Discussion of Ten-Tec Equipment'" 
<tentec at contesting.com>
Sent: Friday, June 10, 2011 3:52 PM
Subject: Re: [TenTec] Omni VI+ BFO


> Just an update - I have been informed by Paul at Ten Tec that even if you
> are able to adjust C16 on the TX Audio Board, so that the SSB "sounds"
> correct to your ear, "the SSB signal might not be centered in the filter
> passband causing distortion on the transmitted signal".
>
> Since I do not own a frequency counter, I am going to be sending my Omni 
> VI+
> back to Ten Tec to have them check alignment in the LSB mode.
>
> Tom
> N3XQ
>
> -----Original Message-----
> From: tentec-bounces at contesting.com [mailto:tentec-bounces at contesting.com]
> On Behalf Of Tom Mandera
> Sent: Friday, June 10, 2011 2:06 PM
> To: tentec at contesting.com
> Subject: [TenTec] Omni VI+ BFO
>
>> Message: 5
>> Date: Thu, 09 Jun 2011 21:59:30 -0400
>> From: "Tom Stone" <sail8 at verizon.net>
>> Subject: [TenTec] Omni VI+ Frequency Display Problem Only On LSB
>> To: <TenTec at contesting.com>
>> Message-ID: <000501cc2712$09890110$1c9b0330$@net>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> Has any owner of an Omni VI+ ever had a problem similar to this? (With 
>> the
>> RIT off, Identical Side tone and Pass Band Tuning set at zero on both
>> rigs)
>> 160M - LSB - Orion II 1.900.000 For the same voice quality (sounds the
>> same)
>> the Omni had to be tuned to 1.899.75
>
> I believe I have a similar issue, but notice it mostly on USB.
>
> I find the most pleasing audio at .85 most of the time.
>
> As was mentioned, it's not a huge deal, given there is no rule that one
> should park the VFO at ".00" or ".50" or .25/75 on the dial, but it's
> somewhat annoying (and my Paragon II didn't exhibit this characteristic,
> but also sports a wider filter choice) and most operators DO sit on an
> even frequency simply because the modern rigs let us.
>
> I guess I'll be looking at the manual a bit more this weekend and maybe I
> can bring it back to alignment.
>
> -Tom
> ke7vux
> Paragon II (blown ALC from static)
> Omni VI+
> Scout
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