K2 spot function is off

[Andrew Moore-4]

I've built and calibrated K2 #4958.  If I use the spot function to tune to the exact frequency of another transceiver, the end result is I'm actually off by about 120 Hz or so.  I've recalibrated a couple times, and my display seems accurate (judging by WWV anyway).  I'm using a 600 Hz sidetone pitch.  After calibrating the displayed frequency, and making adjustments to the trimmer near the 4 MHz osc on the control board, I've done a CAL PLL followed by a CAL FIL (using suggested values from the manual, not using spectrogram...) yet the spot function seems to be off by the same amount every time.

How does one adjust spot?

Thanks,
--Andrew, NV1B
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[Don Wilhelm-3]

Andrew,

There is a lot more than just the SPOT frequency that needs to be adjusted.
The manual settings will get you into the ballpark, and I would call your
120 Hz error 'in the ballpark'.  You can adjust the pitch of your sidetone
in the K2 menu

If you want to do better, you will have to set the K2 reference oscillator
accurately, do a CAL PLL and set the BFOs to properly position the filter
bandpass at your chosen sidetone pitch.  When you have completed that, you
will find the dial display and transmit frequency to be correct within 20 to
30 Hz.

The full instructions to accomplish the dial calibration can be found on my
website http://w3fpr.qrpradio.com or mirror at www.qsl.net/w3fpr and
http:/home.earthlink.net/~w3fpr.

73,
Don W3FPR

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]]On Behalf Of Andrew Moore
> Sent: Thursday, June 30, 2005 8:12 PM
> To: [hidden email]
> Subject: [Elecraft] K2 spot function is off
>
>
> I've built and calibrated K2 #4958.  If I use the spot function
> to tune to the exact frequency of another transceiver, the end
> result is I'm actually off by about 120 Hz or so.  I've
> recalibrated a couple times, and my display seems accurate
> (judging by WWV anyway).  I'm using a 600 Hz sidetone pitch.
> After calibrating the displayed frequency, and making adjustments
> to the trimmer near the 4 MHz osc on the control board, I've done
> a CAL PLL followed by a CAL FIL (using suggested values from the
> manual, not using spectrogram...) yet the spot function seems to
> be off by the same amount every time.
>
> How does one adjust spot?
>
> Thanks,
> --Andrew, NV1B
> _______________________________________________
> Elecraft mailing list
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> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
>  http://mailman.qth.net/mailman/listinfo/elecraft
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