Re: [Elecraft_K3] TCXO Calibration methods


Bob McGraw - K4TAX
 

I use WSJT-X and the Freq Cal mode.  The setup is the same as used for WSJT-X.    I manually via the software select 2.5, 5.0, 10.0 and 15.0 MHz signals.  Typically the software returns a DF of less than 1 Hz.  If it is more than 1 Hz in error, I will by the K3S menu adjust the reference oscillator a few Hz.    My results have proven very successful and accurate with normalized errors of +/- <0.5Hz for frequencies measured. 

73

Bob, K4TAX



On 1/11/2018 4:00 AM, 'David G3YYD' g3yyd2@... [Elecraft_K3] wrote:
 

Mel

 

I use a very simple method.

 

CW mode on K3 tune in an on air standard frequency transmission. The higher the frequency the better but you need a reliable consistent signal. I normally use either 10000KHz or 9996KHz (Russian TX ideal for UK). K3 for minimum bandwidth and display to Hz rather than 10 of Hz. Switch on auto CW tune and press spot button to auto tune the signal. The display will then show the offset from the standard. Adjust the K3 reference frequency value, auto tune again. Repeat as necessary.

 

Due to different modulation schemes can only do this when there is a carrier or CW keying. It is best to avoid doing this with a disturbed geomagnetic field or dawn/dusk on the path as the ionosphere height and propagation mode can be  unstable causing some Doppler shift of the signal.

 

73 David G3YYD

 

From: Elecraft_K3@... [mailto:Elecraft_K3@...]
Sent: 10 January 2018 19:03
To: Elecraft_K3@...
Subject: [Elecraft_K3] TCXO Calibration methods

 




Hello All,

 

I have found that the frequency display and my transmitted signal is off by ~80-100 Hz.  Which of the three methods is the best?    

 

Mel, K6KBE





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