[TenTec] TenTec Digest, Vol 202, Issue 18
Bob McGraw K4TAX
rmcgraw at blomand.net
Thu Oct 24 20:06:41 EDT 2019
To my knowledge there is NO menu available adjustment for correcting any
error in frequency of the reference in the radio. It is a physical
adjustment either by a trimmer by the crystal oven, or on the TXCO,
depending on which the radio has installed.
73
Bob, K4TAX
On 10/24/2019 6:53 PM, Ken Brown wrote:
> I know of the sidetone adjustment, but that's all.
>
> On Thu, Oct 24, 2019, 10:15 Bob McGraw K4TAX <rmcgraw at blomand.net> wrote:
>
>> 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
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>>>>> or, via email, send a message with subject or body 'help' to
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>>>>>
>>>>> 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
>>>>> ***************************************
>>>>>
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