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  1. Yaesu-FT-980
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TX / RX Frequency Alignment

 

I am fairly sure my actual receive and transmit frequencies are off a bit. Are there simple adjustments to correct? My transceiver is untouched from new except for a batter replacement.

Brian WA5UEK
 

Hi,
?? on the right side of the cabinet (facing at the front panel) there is an access hole to TC7001, located in the VFO unit.
With a plastic screwdriver you can adjust this trimmer capacitor against a RX signal coming from a frequency standard station... it's a very easy procedure that can be accomplished without removing any cover.
With the rig tuned at the same frequency offset respect the carrier frequency, you should receive the reference signal with the same audio pitch either in LSB and USB mode. Obviously make sure that the shift/width knob is properly centered before adjusting TC7001.
I also had my rig about 300Hz out of frequency and now is centered again.

In website you can download the FT-980 technical manual where you can go in depth of any maintenance and adjustment procedure.
Here TC7001 is adjusted by means of a frequency counter connected to the given test point. But if you don't have a counter or you don't want to disassemble the rig, this is the easy way that works as well.

73, Francesco IN3FTD


Ottieni
Il giorno 23 Feb 2025, alle ore 16:18, "Brian Harris via " <yahoo.com@groups.io target=_blank>[email protected]> ha scritto:

I am fairly sure my actual receive and transmit frequencies are off a bit. Are there simple adjustments to correct? My transceiver is untouched from new except for a batter replacement. 

Brian WA5UEK
 

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Thank you kind sir.?

On Feb 23, 2025, at 10:13?AM, IN3FTD via groups.io <in3ftd@...> wrote:

?
Hi,
?? on the right side of the cabinet (facing at the front panel) there is an access hole to TC7001, located in the VFO unit.
With a plastic screwdriver you can adjust this trimmer capacitor against a RX signal coming from a frequency standard station... it's a very easy procedure that can be accomplished without removing any cover.
With the rig tuned at the same frequency offset respect the carrier frequency, you should receive the reference signal with the same audio pitch either in LSB and USB mode. Obviously make sure that the shift/width knob is properly centered before adjusting TC7001.
I also had my rig about 300Hz out of frequency and now is centered again.

In website you can download the FT-980 technical manual where you can go in depth of any maintenance and adjustment procedure.
Here TC7001 is adjusted by means of a frequency counter connected to the given test point. But if you don't have a counter or you don't want to disassemble the rig, this is the easy way that works as well.

73, Francesco IN3FTD


Ottieni
Il giorno 23 Feb 2025, alle ore 16:18, "Brian Harris via " <yahoo.com@groups.io target=_blank>[email protected]> ha scritto:
I am fairly sure my actual receive and transmit frequencies are off a bit. Are there simple adjustments to correct? My transceiver is untouched from new except for a batter replacement. 

Brian WA5UEK
 

Hey Brian.
Last year I gave my '980' to a complete service - a complte check-up. It needed about 6 month and costs about 850,- �. One of the points to make better, was
the bit of frequencies-difference. Not much difference - but even not exact. What the repair-shop tells me:? the reason is the 50years old xtal. You can adjust a little bit - but not enough as
it needed.?If you can get a new xtal - and it means 'a very new'?x-tal, you can change it. But it's not easy - and perhaps it is not necessary for this little difference.
That's what I can tell you what a specialist have told me last year.
Perhaps it helps.
vy73 de DL2EBZ??
 

Hi Brian,
?
There is nice article on the thermally-stabilized crystal in the Files section (how it works, how to adjust): See below:
?
?
Hope this helps,
?
--
-Mat Breton, N8TW
 

Hi DL2EBZ,
?
There is certainly a very limited range on the "stock" variable pulling capacitor in the oscillator circuit.
?
If you run out of range, you can add or remove capacitance by changing values of the fixed parallel capacitors. Be sure to use high quality NG0/C0G capacitors if you do this. This can allow you to continue to "calibrate" your rig without replacing the crystal.
?
--
-Mat Breton, N8TW
 

Thank you for this information, Mat. I dont know that until yet. Very good to know !!
vy73 de DL23EBZ, Bodo

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