K2 - best frequency accuracy?

[David C Dawson-2]

My question is a bit complex:

first, by using rig in CW mode and tuning to 10 MHz, I turned on the spot function and tuned the VFO to zero beat with the station carrier. I followed the VFO setting procedure on page 101 of the K2 Manual, and seemed to get it spot-on (maybe +/- 5 Hz?)

Then I compared the frequency accuracy with different filters and found that the zero-beat frequency seems to vary with the filter.
(not by a whole lot, maybe within +0  -  +30 Hz above the second-widest CW filter.

I'd like the VFO frequency to be accurate as possible, and I realize that the BFO needs to be just as accurate.

I'd like the filters to be consistant.

My question is:
How can I set the VFO as accurately as possible, how accurate is that, same with the BFO and filters?


Thanks
--
David Dawson

The Ranger isn't gonna like it, Yogi.
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[Don Wilhelm-4]

David,

I suggest you go to my website www.w3fpr.com and look at the article
dealing with K2 Dial Calibration.  It explains the entire procedure,
including the use of Spectrogram to set the filters.  The starting point
for doing dial calibration is to set the 4 MHz reference as accurately
as you can.  That will determine how well the dial calibration procedure
results will be.  After doing the procedure (both CAL PLL and CAL FIL),
th 4 MHz oscillator can drift all it wants because it is not used
dynamically for anything other than an oscillator for the MCU, but it
must be accurate for the duration of the CAL PLL and CAL FIL procedures.

The bottom line on the K2 accuracy is that it has a limit of about 20 Hz
due to the DAC resolution.
I highly encourage you to use Spectrogram when tuning WWV (use SSB mode
and position the transmitted tones at the proper audio frequency), and
for setting the filters and their BFOs.  For me, there is no other
accurate way to do it.

73,
Don W3FPR


David C Dawson wrote:

> My question is a bit complex:
>
> first, by using rig in CW mode and tuning to 10 MHz, I turned on the spot function and tuned the VFO to zero beat with the station carrier. I followed the VFO setting procedure on page 101 of the K2 Manual, and seemed to get it spot-on (maybe +/- 5 Hz?)
>
> Then I compared the frequency accuracy with different filters and found that the zero-beat frequency seems to vary with the filter.
> (not by a whole lot, maybe within +0  -  +30 Hz above the second-widest CW filter.
>
> I'd like the VFO frequency to be accurate as possible, and I realize that the BFO needs to be just as accurate.
>
> I'd like the filters to be consistant.
>
> My question is:
> How can I set the VFO as accurately as possible, how accurate is that, same with the BFO and filters?
>
>
> Thanks
>  
>  

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