Bob,
Your questions #1 and #2 have merit, no question about it.
The third however reflects more on you than me and is really uncalled for.
It helps to prove my comment on growing intolerance for opinions or comments
that run to the contrary on this reflector.
I learned long ago about "P'n" contests.
Thanks for helping to prove my point.
N1LQ-Dave
----- Original Message -----
From: "Robert & Linda McGraw K4TAX" <RMcGraw@Blomand.Net>
To: "David Hammond" <dhhdeh@concentric.net>; "tentec reflector"
<tentec@contesting.com>
Sent: Wednesday, October 02, 2002 10:22 PM
Subject: Re: [TenTec] Omni VI Plus freq. readout
> Three questions:
>
> 1. When was the Onmi designed and when was the IC 756 Pro II designed?
> 2. Do you think time base and design technology stood still during this
> period?
> 3. Does the tuning knob on your radio work and do you know how to
correctly
> use it?
>
> >From the Tentec Omni VI+ manual:
> FREQUENCY ACCURACY +/- 50 Hz @ 25 degrees C. (NOTE: the frequency will
> shift noticeably for 1 - 2 minutes while the oven heats up when first
> turned on. Leave DC power connected to the rear panel el eliminate this
> turn-on drift).
>
> And I see all the P'n and Moanin' over 10 Hz.
>
> I use my Omni VI+ on 20M PSK31 and yes I see many signals in the 500 Hz
> passband. Never have a problem finding my schedule or frequency. Guess
my
> tuning knob works and I know how to use it.
>
>
> 73
> Bob, K4TAX
>
> ----- Original Message -----
> From: "David Hammond" <dhhdeh@concentric.net>
> To: "tentec reflector" <tentec@contesting.com>
> Sent: Wednesday, October 02, 2002 8:58 PM
> Subject: [TenTec] Omni VI Plus freq. readout
>
>
> > Hi Everyone,
> >
> > Once again I am compelled to comment on this thread having spent a lot
of
> > time seeking to improve this very specific Omni VI problem. It's real
and
> it
> > does exist.
> >
> > After 5 1/2 years of Omni VI ownership (prior to selling it this past
> > Spring), I chased improved frequency readout accuracy on this radio and
> came
> > up with the following conclusions. My Omni VI suffered from both
frequency
> > repeatability and accuracy problems considerably greater than other
> > transceivers I have owned. In fairness to Ten Tec though, the Omni VI
> and
> > VI+ were never spec'ed to super-precise frequency accuracy. Nevertheless
> > this problem bugged the heck out of me over time. So I embarked on a
> series
> > of modifications seeking an improvement. Funny, I thought that
> > experimentation was in the true spirit of ham radio from days gone by.
> > Anyway......
> >
> > The frequency repeatability problem was vastly improved if not solved
> > outright by substituting the 2ppm TCXO for the original crystal oven in
> the
> > reference oscillator. A tremendous modification for older Omni VI's.
About
> > $40 and hours work. As I have said before, it is the best change Ten
Tec
> > has come up with for the Omni VI and VI+. While many crystals do exist
in
> > the radio's L/O circuit, unlike in the Omni V, the VI's L/O crystals are
> > tied to the reference oscillator and cannot be individually trimmed per
> se,
> > for improved frequency accuracy. Small deviations do exist from band to
> band
> > but are not a real bother IMO.
> >
> > Th real culprits in the Omni VI are the BFO crystals located on the
board
> > directly under the in-board speaker. This circuit is subject to
> significant
> > thermal drift coming and going in response to rig-generated heat and
even
> > changes in ambient room or Wx temperature. Attempting to fix this
problem
> I
> > first removed the speaker to allow for convective cooling up through the
> > speaker grill. Good but not great results. Then I substituted higher
> > quality ceramic trimmers for the USB and LSB trimmers. No real
> improvement.
> > Finally I ordered custom built USB and LSB BFO crystals from ICM in
> > Oklahoma. About $70 and an hour's work later, I had them installed.
This
> > change removed about 99.5% of the thermal drift resulting in better than
> > spec'ed display accuracy. The BFO circuit is the culprit in this rig
> > causing the problem with frequency accuracy. It is noticeable in SSB
over
> > periods of extended TX activity. New custom crystals and its just about
> > gone.
> >
> > I must join with Adam and George in telling you that my new IC 756 Pro
II
> > has provided me with amazing frequency accuracy and repeatability. And
to
> > those of you commenting that it does not matter I beg to differ. It
> matters
> > to many of us a whole lot. I simply got sick and tired of always being
off
> > everyone else's frequency. It also matters if you want to work MARS.
Check
> > out the MARS rig requirements of late.
> >
> > I will also add that some of the snide comments including "sell your
Omni
> > and keep you Jap rig then you won't be so stressed out" once again
> > demonstrate to me the developing intolerance of some on this list.
> > Regrettable.
> >
> > I have both ICOM and Ten Tec gear here now but hold no blind allegiance
to
> > any manufacturer. Competition breeds the best product for us all. To
each
> > his own. This specific problem was/is important to me and many others
who
> I
> > have spoken with but who care not to comment on the reflector.
> >
> > And on a final unrelated note, I wish TT would put some good quality
Orion
> > photos on the TT Web site. It needs to be seen better than is being
> shown.
> >
> > 73 de N1LQ-Dave
> >
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
>
>
>
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