Hi Wes,
How can I find that frequency adjust in the Omni VI software menu?
Thanks, Ken N6KB
On Thu, Oct 24, 2019 at 7:15 AM wes Bolin <k5apl41@gmail.com> wrote:
> The OMNI VI is a piece of cake and you don't have to open the case. In the
> software menu you can actually adjust the Oscillator frequency from the
> front panel. Its in the manual. I have done it years agoso
> don't remember the details. The OMNI V requires you to open the cover.
> The OMNI V did not have a TCXO, but the OMNI VI does, so you need to give
> it time to stabilize the frequency before you do any
> adjustments. Some guys have disabled the TCXO to minimize the drift after
> turn-on and stabilization. At any rate you have options to get it on
> frequency. BTW the best way to get it on the proper frequency is to have a
> frequency standard, not the other guy's comments. On 20M, the net on
> 14.300 is always very close to 14.300. Have fun.
> Wes
>
> On Thu, Oct 24, 2019 at 11:00 AM <tentec-request@contesting.com> wrote:
>
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> > Today's Topics:
> >
> > 1. frequency adj. (wt4t@reagan.com)
> > 2. Re: frequency adj. (Bob McGraw K4TAX)
> > 3. Re: frequency adj. (Gary Follett)
> > 4. Re: frequency adj. (Ken Brown)
> > 5. Re: frequency adj. (wt4t@reagan.com)
> >
> >
> > ----------------------------------------------------------------------
> >
> > Message: 1
> > Date: Wed, 23 Oct 2019 15:13:25 -0500 (CDT)
> > From: wt4t@reagan.com
> > To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
> > Subject: [TenTec] frequency adj.
> > Message-ID: <1571861605.226246652@webmail.reagan.com>
> > Content-Type: text/plain; charset="UTF-8"
> >
> >
> > Have a OMNI VI+ ,started to set up a position for the rig today and
> > noticed the frequency readout was off about .22 hz. I remember my old
> > omni V had a simple adjustment point to tweek the readout. Same on the
> + ?
> > if so what board and location would I find it?
> > The older I get the more I for get. 73
> > dale wt4t
> >
> > ------------------------------
> >
> > Message: 2
> > Date: Wed, 23 Oct 2019 16:56:07 -0500
> > From: Bob McGraw K4TAX <rmcgraw@blomand.net>
> > To: dale via TenTec <tentec@contesting.com>
> > Subject: Re: [TenTec] frequency adj.
> > Message-ID: <147bdd2c-2540-5db0-8b5c-9c3862e2856d@blomand.net>
> > Content-Type: text/plain; charset=utf-8; format=flowed
> >
> > Dale:
> >
> > The spec as I recall is +/- 50 Hz.? Looks as though you are well within
> > that spec.? Oh by the way,?? .22 Hz is ~1/4 of one Hertz. I think you
> > mean 22 Hz.
> >
> > You should check all bands and determine the error on each one. Each one
> > has a crystal oscillator operating in a Phase Lock Loop based on the
> > reference frequency.?? Earlier radios had a crystal oven which required
> > time to reach operating temperature.? It was not at uncommon for that
> > oven to fail and there was no temperature control.?? Also, if you turn
> > off the DC power to the radio, you should wait about 1 hr for the oven
> > to heat and stabilize.? Later radios had a TCXO which had a trimmer
> > accessed through a small hole in the top of the device.? They are about
> > the size of a postage stamp located on the Logic Board.?? Also you will
> > find that the BFO oscillators are not temperature stabilized.? Any error
> > or drift due to temperature change will cause an error in absolute
> > frequency.?? For these reasons, the spec is +/- 50Hz.
> >
> > Yes, you can correct the read-out but what frequency is the radio on???
> > Remember the digital read-out is just that, and is not a frequency
> > measurement.
> >
> > My advice, don't tamper with it.? You'll like come away frustrated and
> > maybe worse off than 22 Hz.
> >
> > 73
> >
> > Bob, K4TAX
> >
> > On 10/23/2019 3:13 PM, dale via TenTec wrote:
> > > Have a OMNI VI+ ,started to set up a position for the rig today and
> > noticed the frequency readout was off about .22 hz. I remember my old
> > omni V had a simple adjustment point to tweek the readout. Same on the
> + ?
> > if so what board and location would I find it?
> > > The older I get the more I for get. 73
> > > dale wt4t
> > > _______________________________________________
> > > TenTec mailing list
> > > TenTec@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/tentec
> > >
> >
> >
> >
> > ------------------------------
> >
> > Message: 3
> > Date: Wed, 23 Oct 2019 17:02:48 -0500
> > From: Gary Follett <dukeshifi@comcast.net>
> > To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
> > Cc: wt4t@reagan.com
> > Subject: Re: [TenTec] frequency adj.
> > Message-ID: <397421D8-7678-4F1F-B742-F84126145274@comcast.net>
> > Content-Type: text/plain; charset=utf-8
> >
> > I suspect you MEAN off by 0.22 KHz not 0.22 Hz?
> >
> > Is it off by the same amount on all bands?
> >
> > Frequency calibration of the crystal board on an Omni VI is quite
> > different due to the PLL used for the crystal oscillator board compared
> > with the open loop operation of the Omni V. Alignment of frequency of
> this
> > board simply involves adjustment of the reference oscillator on the logic
> > board. It should be 20 MHz dead on.
> >
> > If it?s off by the same amount on all bands, it could also be the BFO.
> > However, this error in frequency should depend upon mode. LSB and USB
> > should show different errors and CW yet another. Alignment of the BFO is
> in
> > the TX Audio section for the manual. There are separate trim capacitors
> for
> > each mode.
> >
> > It is quite common for the trimmer caps in the BFO to become ?dirty? just
> > like a potentiometer or switch can get ?dirty?. Cleaning is a simple
> matter
> > of lightly spraying with non-residue contact cleaner, rotate full range
> > several times, let dry overnight at least, then calibrate the BFO
> trimmers.
> >
> > Sometimes you can get lucky and clean the trimmers by dry operating
> > through full range several times without the cleaner. Then you can
> > calibrate immediately since there would be no trapped solvent to
> evaporate
> > out of crannies.
> >
> >
> > Gary
> >
> > W0DVN
> >
> >
> > > On Oct 23, 2019, at 3:13 PM, dale via TenTec <tentec@contesting.com>
> > wrote:
> > >
> > >
> > > Have a OMNI VI+ ,started to set up a position for the rig today and
> > noticed the frequency readout was off about .22 hz. I remember my old
> > omni V had a simple adjustment point to tweek the readout. Same on the
> + ?
> > if so what board and location would I find it?
> > > The older I get the more I for get. 73
> > > dale wt4t
> > > _______________________________________________
> > > TenTec mailing list
> > > TenTec@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/tentec
> >
> >
> >
> > ------------------------------
> >
> > Message: 4
> > Date: Wed, 23 Oct 2019 15:00:55 -1000
> > From: Ken Brown <kenradiobrown@gmail.com>
> > To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
> > Subject: Re: [TenTec] frequency adj.
> > Message-ID:
> > <CAGnjFfnmpGhnX+HSLjgrih8E=2z9ctYwGJ=
> > O3kkpbkyMej0f5Q@mail.gmail.com>
> > Content-Type: text/plain; charset="UTF-8"
> >
> > If you really mean 0.22 Hz you should consider yourself fortunate and not
> > mess with it. If it is 0.22 kHz off you can make it better, but not much.
> > I agree with Bob that you should check it on all bands. I expect you will
> > find it better one some bands and worse on others.
> >
> > My experience with two Omni VIs is that even when you get the BFO
> > frequencies as perfect as possible, say less than 1 Hz beat with a known
> > accurate reference synthesizer, and get the 20 MHz reference similarly
> > correct, the readout will still not be perfect. Off by tens of Hertz on
> > some bands. And this is the case even after confirming that the band
> select
> > crystal oscillators are locked to the reference.
> >
> > I have found that the offset is not necessarily proportionate to the
> > operating frequency, which is what you would expect if only the 20 MHz
> > reference was slightly off and the PLL system divide by numbers were
> > exactly correct. My theory is that the PLL system does not have high
> enough
> > resolution divide by numbers to really get the exact correct frequency on
> > every band. I think Ten-Tec rounded the numbers off to make the PLL work
> > faster and quieter, while still maintaining the specified +/- 50 Hz
> > accuracy.
> >
> > I would love to hear from someone who knows about the PLL program running
> > in the Omni VI, and knows what numeric values are in the ROM.
> >
> > DE N6KB
> >
> >
> > On Wed, Oct 23, 2019 at 10:25 AM dale via TenTec <tentec@contesting.com>
> > wrote:
> >
> > >
> > > Have a OMNI VI+ ,started to set up a position for the rig today and
> > > noticed the frequency readout was off about .22 hz. I remember my old
> > > omni V had a simple adjustment point to tweek the readout. Same on the
> > + ?
> > > if so what board and location would I find it?
> > > The older I get the more I for get. 73
> > > dale wt4t
> > > _______________________________________________
> > > TenTec mailing list
> > > TenTec@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/tentec
> > >
> >
> >
> > ------------------------------
> >
> > Message: 5
> > Date: Thu, 24 Oct 2019 07:56:47 -0500 (CDT)
> > From: wt4t@reagan.com
> > To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
> > Subject: Re: [TenTec] frequency adj.
> > Message-ID: <1571921807.142530004@webmail.reagan.com>
> > Content-Type: text/plain; charset="UTF-8"
> >
> >
> > Bob
> > thanks for your info. your right , I guess if it really is not broke ,
> > don't fix it.
> > dale
> > -----Original Message-----
> > From: "Bob McGraw K4TAX" <rmcgraw@blomand.net>
> > Sent: Wednesday, October 23, 2019 4:56pm
> > To: "dale via TenTec" <tentec@contesting.com>
> > Subject: Re: [TenTec] frequency adj.
> >
> >
> >
> > Dale:
> >
> > The spec as I recall is +/- 50 Hz. Looks as though you are well within
> > that spec. Oh by the way, .22 Hz is ~1/4 of one Hertz. I think you
> > mean 22 Hz.
> >
> > You should check all bands and determine the error on each one. Each one
> > has a crystal oscillator operating in a Phase Lock Loop based on the
> > reference frequency. Earlier radios had a crystal oven which required
> > time to reach operating temperature. It was not at uncommon for that
> > oven to fail and there was no temperature control. Also, if you turn
> > off the DC power to the radio, you should wait about 1 hr for the oven
> > to heat and stabilize. Later radios had a TCXO which had a trimmer
> > accessed through a small hole in the top of the device. They are about
> > the size of a postage stamp located on the Logic Board. Also you will
> > find that the BFO oscillators are not temperature stabilized. Any error
> > or drift due to temperature change will cause an error in absolute
> > frequency. For these reasons, the spec is +/- 50Hz.
> >
> > Yes, you can correct the read-out but what frequency is the radio on?
> > Remember the digital read-out is just that, and is not a frequency
> > measurement.
> >
> > My advice, don't tamper with it. You'll like come away frustrated and
> > maybe worse off than 22 Hz.
> >
> > 73
> >
> > Bob, K4TAX
> >
> > On 10/23/2019 3:13 PM, dale via TenTec wrote:
> > > Have a OMNI VI+ ,started to set up a position for the rig today and
> > noticed the frequency readout was off about .22 hz. I remember my old
> omni
> > V had a simple adjustment point to tweek the readout. Same on the + ? if
> so
> > what board and location would I find it?
> > > The older I get the more I for get. 73
> > > dale wt4t
> > > _______________________________________________
> > > TenTec mailing list
> > > TenTec@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/tentec
> > >
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
> > ------------------------------
> >
> > Subject: Digest Footer
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
> >
> > ------------------------------
> >
> > End of TenTec Digest, Vol 202, Issue 18
> > ***************************************
> >
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