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@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@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
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------------------------------
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
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------------------------------
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
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------------------------------
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
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------------------------------
Subject: Digest Footer
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------------------------------
End of TenTec Digest, Vol 202, Issue 18
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