[TenTec] TenTec Digest, Vol 202, Issue 18
Bob McGraw K4TAX
rmcgraw at blomand.net
Thu Oct 24 16:15:25 EDT 2019
Yes, I would like to know where the software adjustment is located. I
don't see that item in the Menu system.
73
Bob, K4TAX
On 10/24/2019 1:15 PM, Ken Brown wrote:
> 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 at 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 at contesting.com> wrote:
>>
>>> Send TenTec mailing list submissions to
>>> tentec at contesting.com
>>>
>>> To subscribe or unsubscribe via the World Wide Web, visit
>>> http://lists.contesting.com/mailman/listinfo/tentec
>>> or, via email, send a message with subject or body 'help' to
>>> tentec-request at contesting.com
>>>
>>> You can reach the person managing the list at
>>> tentec-owner at contesting.com
>>>
>>> When replying, please edit your Subject line so it is more specific
>>> than "Re: Contents of TenTec digest..."
>>>
>>>
>>> Today's Topics:
>>>
>>> 1. frequency adj. (wt4t at 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 at reagan.com)
>>>
>>>
>>> ----------------------------------------------------------------------
>>>
>>> Message: 1
>>> Date: Wed, 23 Oct 2019 15:13:25 -0500 (CDT)
>>> From: wt4t at reagan.com
>>> To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
>>> Subject: [TenTec] frequency adj.
>>> Message-ID: <1571861605.226246652 at 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 at blomand.net>
>>> To: dale via TenTec <tentec at contesting.com>
>>> Subject: Re: [TenTec] frequency adj.
>>> Message-ID: <147bdd2c-2540-5db0-8b5c-9c3862e2856d at 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 at contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>>
>>>
>>>
>>> ------------------------------
>>>
>>> Message: 3
>>> Date: Wed, 23 Oct 2019 17:02:48 -0500
>>> From: Gary Follett <dukeshifi at comcast.net>
>>> To: Discussion of Ten-Tec Equipment <tentec at contesting.com>
>>> Cc: wt4t at reagan.com
>>> Subject: Re: [TenTec] frequency adj.
>>> Message-ID: <397421D8-7678-4F1F-B742-F84126145274 at 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 at 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 at contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>
>>>
>>> ------------------------------
>>>
>>> Message: 4
>>> Date: Wed, 23 Oct 2019 15:00:55 -1000
>>> From: Ken Brown <kenradiobrown at gmail.com>
>>> To: Discussion of Ten-Tec Equipment <tentec at contesting.com>
>>> Subject: Re: [TenTec] frequency adj.
>>> Message-ID:
>>> <CAGnjFfnmpGhnX+HSLjgrih8E=2z9ctYwGJ=
>>> O3kkpbkyMej0f5Q at 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 at 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 at contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>>
>>>
>>> ------------------------------
>>>
>>> Message: 5
>>> Date: Thu, 24 Oct 2019 07:56:47 -0500 (CDT)
>>> From: wt4t at reagan.com
>>> To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
>>> Subject: Re: [TenTec] frequency adj.
>>> Message-ID: <1571921807.142530004 at 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 at blomand.net>
>>> Sent: Wednesday, October 23, 2019 4:56pm
>>> To: "dale via TenTec" <tentec at 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 at contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>>
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>
>>> ------------------------------
>>>
>>> Subject: Digest Footer
>>>
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>
>>>
>>> ------------------------------
>>>
>>> End of TenTec Digest, Vol 202, Issue 18
>>> ***************************************
>>>
>> _______________________________________________
>> TenTec mailing list
>> TenTec at contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
More information about the TenTec
mailing list