[K2] Frequency Calibration using WWV Audio Tones

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

[K2] Frequency Calibration using WWV Audio Tones

Elecraft mailing list
I was wondering if anyone had tried doing the reference oscillator frequency calibration for a K2 without the rather troublesome step of accurate zero-beating by feeding the 500/600 Hz audio tones from WWV/WWVH to a computer sound card or smart phone spectrum analyzer, or similar program?  It's pretty easy to read these audio frequencies out to a precision of 1 Hz or so using Spectran or Spectrogram, for example.

Right now, I'm seeing both WWV and WWVH tones (at the same time!) on my computer screen (within a few Hz of the correct audio frequencies), with the K2 tuned to 15000.24 kHz, so it really ought to be re-calibrated.

Are there any issues with this option, before I start into the whole process?

73,
Steve VE3SMA
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: [K2] Frequency Calibration using WWV Audio Tones

Don Wilhelm
Steve,

That is exactly how I tune WWV before reading the VFO (TP1) and BFO
(TP2) frequencies.  Adjust Control Board C22 until the 3 lower order
digits match (since you are listening to a station known to be on a
xx000.000 boundary the subtraction process is a snap.
You may want to LOC the VFO so the knob is not accidentally changed.

Additional information on my website www.w3fpr.com article on K2 Dial
Calibration.

After doing CAL PLL and CAL FIL, go back to WWV and check the results.
If you are within 20 Hz, that is about as good as you can expect.  The
variation in BFO frequencies between filters in the K2 can be as much as
20 Hz because of the resolution of the DAC.

73,
Don W3FPR

On 10/31/2017 2:17 PM, Steve Kavanagh via Elecraft wrote:

> I was wondering if anyone had tried doing the reference oscillator frequency calibration for a K2 without the rather troublesome step of accurate zero-beating by feeding the 500/600 Hz audio tones from WWV/WWVH to a computer sound card or smart phone spectrum analyzer, or similar program?  It's pretty easy to read these audio frequencies out to a precision of 1 Hz or so using Spectran or Spectrogram, for example.
>
> Right now, I'm seeing both WWV and WWVH tones (at the same time!) on my computer screen (within a few Hz of the correct audio frequencies), with the K2 tuned to 15000.24 kHz, so it really ought to be re-calibrated.
>
> Are there any issues with this option, before I start into the whole process?
>
> 73,
> Steve VE3SMA
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: [K2] Frequency Calibration using WWV Audio Tones

Bob McGraw - K4TAX
In reply to this post by Elecraft mailing list
See the article "Transmit and Receive on Frequency" as published in
Sept. 2015 QST.

73

Bob, K4TAX


On 10/31/2017 1:17 PM, Steve Kavanagh via Elecraft wrote:
> I was wondering if anyone had tried doing the reference oscillator frequency calibration for a K2 without the rather troublesome step of accurate zero-beating by feeding the 500/600 Hz audio tones from WWV/WWVH to a computer sound card or smart phone spectrum analyzer, or similar program?  It's pretty easy to read these audio frequencies out to a precision of 1 Hz or so using Spectran or Spectrogram, for example.
>
> Right now, I'm seeing both WWV and WWVH tones (at the same time!) on my computer screen (within a few Hz of the correct audio frequencies), with the K2 tuned to 15000.24 kHz, so it really ought to be re-calibrated.
>
> Are there any issues with this option, before I start into the whole process?
>
> 73,
> Steve VE3SMA
>


______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]