I also would be interested in the BFO mod and I actaully have the TCXO kit,
but haven't installed it. I'm in need of a frequency counter for all the
required alignments. I also need to do a general alignment of my Omni VI(opt
3). My RTTY tones are about 130 Hz shift rather than 170 (according to MixW
running on a second radio)
Are there any recommendations out there on a suitable frequency counter? Is
it possible to use a second receiver and zero beat?
73,
Mark
----- Original Message -----
From: "John L Merrill" <jmerrill1@adelphia.net>
To: <johnclif@ix.netcom.com>; <tentec@contesting.com>
Sent: Saturday, March 15, 2003 17:10 PM
Subject: RE: [TenTec] OmniVI Opt3 question
> John:
> Great information. Thanks. I'm definitely interested in the "BFO Kit".
>
> 73, John N1JM
>
> -----Original Message-----
> From: tentec-bounces@contesting.com
> [mailto:tentec-bounces@contesting.com]On Behalf Of John Clifford
> Sent: Saturday, March 15, 2003 3:50 PM
> To: tentec@contesting.com
> Subject: RE: [TenTec] OmniVI Opt3 question
>
>
> I have an Omni VI/Opt 1, and the frequency stability has benefited GREATLY
> from two modifications.
>
> The first mod is to replace the crystal oven with the TXCO. This is not a
> big deal to install, although the instructions could be a little clearer.
I
> don't know if there is, and didn't see, a difference in stability once the
> rig has been running for a half-hour between the two setups, but the TXCO
> doesn't drift nearly as much during warm-up. This is one of those changes
> that can't hurt, but probably doesn't help much if at all. If anything,
it
> keeps the rig so that the display matches the actual frequency better but
> doesn't seem to affect staying on a particular frequency once the rig is
> warmed up.
>
> The second mod, and it really makes a difference, is to replace the two
> crystals on the BFO board with higher tolerance parts. I found that when
I
> did this, I was able to hold to within 10 hz... the factory crystals would
> allow the rig to drift during transmit as much as 40 hz (within Ten-Tec's
> spec of 50 hz, which works for CW and SSB but isn't suitable for some of
the
> newer HF digital modes). Ten-Tec will tell you that the rig is working
> within spec (which it is) but I wanted better.
>
> This doesn't seem like a lot, but if you're running a mode where tuning is
> critical (like MFSK), the difference is in a rig that is hard to keep
tuned
> and one that stays tuned. In PSK31, the difference here is that you don't
> walk down the band. Even when you have transmit locked in your software,
> you will start seeing the transmit and receive indicators on your
waterfall
> 'walk', and if the other op isn't similarly locked HE will walk down the
> band in order to stay with you.
>
> The crystal change will run you about $50 for the two crystals including
> shipping, and take about 20 minutes, most of that time being taking the
top
> cover off, unplugging the various cables, and reversing this when you
> re-install the board. You will need a frequency counter to re-align this
> board once you have completed the modification.
>
> Note that the 9.003300 Mhz crystal is not an off-the-shelf product. I
tried
> the crystal #s recommended in the list archive and they don't work... the
> crystal can't be 'pulled' far enough. I spent $60 and waited for over a
> month to get a custom crystal made, but now I have a source for these and
> they know what to do. The custom crystal is designed specifically to be
> frequency stable even though it is being pulled a way. (I think this is
why
> the BFO board was redesigned for the VI+.) These crystals are much
cheaper
> if we can put together a bulk order, so if there is any interest in a 'BFO
> kit' for the VI please contact me.
>
> I can't recommend this mod highly enough. It really makes the Omni VI a
> great rig for HF digital modes, and VERY frequency stable (much better
than
> the original specs).
>
> - jgc
>
> John Clifford KD7KGX
>
> Heathkit HW-9 WARC/HFT-9/HM-9
> Elecraft K2 #1678 /KSB2/KIO2/KBT2/KAT2/KNB2/KAF2/KPA100
> Ten-Tec Omni VI/Opt1
>
> email: kd7kgx@arrl.net
>
>
> > -----Original Message-----
> > From: tentec-bounces@contesting.com
> > [mailto:tentec-bounces@contesting.com]On Behalf Of John L Merrill
> > Sent: Saturday, March 15, 2003 10:45 AM
> > To: Pete Juliano
> > Cc: Tentec
> > Subject: RE: [TenTec] OmniVI Opt3 question
> >
> >
> > Pete:
> > Thanks for the info. I just a beautiful used one with Opt3. I'll give
Ten
> > Tec a call on Monday.
> >
> > 73,
> > John
> > -----Original Message-----
> > From: Pete Juliano [mailto:jessystems@cablespeed.com]
> > Sent: Saturday, March 15, 2003 1:37 PM
> > To: John L Merrill
> > Subject: Re: [TenTec] OmniVI Opt3 question
> >
> >
> > Hi John,
> >
> > About six months ago I bought from Ten Tec a used Omni 6+
> > Factory Option 3
> > upgrade and asked about the TCXO --they said I had two options either
> > purchase and install it myself or have them do it. I had them do
> > it as there
> > is some tweaking and adjusting required although I suspect it is not
> > difficult or detailed. But since the unit I was buying was covered by a
> > warranty why not have that piece covered as well. At that time I think
the
> > TCXO was under $60.
> >
> > So the short answer is that six months ago they were carrying
> > the TCXO and
> > it can be user installed.
> >
> > The TCXO I think is a very worthwhile accessory and really adds to the
> > value. I leave the power supply on at all times and find that the
> > Omni 6+ is
> > always right on frequency. I frequently participate in a net where the
net
> > controller starts chewing on you if you are more than 20 hertz off
> > frequency. Guess he likes to tout that he is never off frequency.
> > I set the
> > net frequency in VFO B and never had him tell me I was off frequency or
> > drifting!
> >
> > Call Stan at Ten Tec and I am sure he will give you the latest
> > info. Oh, I
> > believe that Ten Tec must outsource the TCXO as my Omni 6+ was held up
in
> > their shop for about a week until they received a new shipment of
> > boards. So
> > that is another possibility as their source might have boards too.
> >
> > 73's
> > Pete W6JFR
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
>
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