Component aging including crystal. Tweak the fixed value of the C in the
Oscillator. Still the HF Osc for a given band may need adjusting.
Bob, K4TAX
Sent from my iPhone
> On Nov 6, 2018, at 9:42 AM, Sven Ladegast via TenTec <tentec@contesting.com>
> wrote:
>
> Hello Bob,
>
> Many thanks for your answer! - I did the BFO alignment already and all BFO
> frequencies are okay, even CW TX is set to 9.00300 MHz.
>
> Because there is no BFO in mode *FM*, the carrier is produced by a separate
> XTAL on the FM board. This XTAL drives a Colpitts oscillator and is tuned by
> a trimmer coil L2. I cannot get this single frequency aligned. The maximum
> frequency with the core fully turned out of the coil is 8.9965 MHz and so my
> FM TX carrier is always almost 1.5 kHz off the RX.
>
> Though I do not use FM very often, it would be nice if the radio does work
> completely!
>
> vy 73!
>
> Sven, DJ2AT
>
> Am 06.11.2018 16:34, schrieb Bob McGraw K4TAX:
>> Perform the BFO alignment in the sequence defined in the manual. All
>> steps must be done regardless of the mode you operate or do not
>> operate. Be sure the radio is up to operating temp. Perform the
>> sequence 2 or 3 times as there is interaction between the adjustments.
>> The set the Master Osc so the radio displays the correct frequency.
>> The display is not a true frequency measurement but is a display based
>> on the Master Osc. It does not know if the band Oscillator is off
>> frequency. Also you can trim each band to get the frequency per band a
>> bit closer.
>> Bob, K4TAX
>> Sent from my iPhone
>>> On Nov 6, 2018, at 9:04 AM, Sven Ladegast via TenTec
>>> <tentec@contesting.com> wrote:
>>> Hello folks,
>>> I do have trouble aligning the TX carrier frequency on an Omni 6+.
>>> With no modulation applied, the TX carrier frequency shall be 9.00300 MHz
>>> measured at connector 73 of the board. I used a TMP-BNC cable and connected
>>> it to connector 73 and connected the BNC connector to my accurate frequency
>>> counter using a T-connector and additional 50 Ohms termination.
>>> The TX carrier frequency is aligned by turning the core of L2 but with the
>>> core complete turned out of the coil I get a maximum frequency of 8.9965
>>> MHz and cannot get to 9.00300 MHz. Do have anyone an idea what is going
>>> wrong? Aged XTAL?
>>> 73!
>>> Sven, DJ2AT
>>> _______________________________________________
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>
> --
> Sven Ladegast
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>
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