[Elecraft] KX3: thermal frequency drift

[Matt VK2RQ]

You are probably better off zero-beating to WWV. You should easily be able to get within 500mHz or less.

73,
Matt VK2RQ

> On 12 Apr 2014, at 6:39 am, Edward R Cole <kl7uw at acsalaska.net> wrote:
> 
> It was suggested I do the Temp Compensation Procedure.  Unfortunately I do not have a stable 50-MHz signal source. However I did run the Reference Frequency Calibration using my XG3.  Call this "Part Two":
> 
> I sampled the RF output of the XG3 with my counter and also input that to the KX3 for the Calib.  This required running at 0 dBm to inject strong enough signal for the counter (approx -3 dBm).  I turned on the ATT for the KX3 to keep input from overdriving.  Got about S9 signal level.
> 
> I got it adjusted to within about 2-Hz.  The XG3 drifts approx +/- 2 Hz so difficult to set the Ref*Frequency using it.  But that eliminated most of the 38 Hz offset I saw last night.  Running the Tx at 5w afterward drift was in the range of 0 to +7 Hz for a 50-second key down run.  The drift is not steady in one direction so average error is probably in the neighborhood of +5 Hz with 5-Hz uncertainty in the measurement.  Crude but gives a ballpark idea what to expect.
> 
> Today's measurements were all with new heat sink installed.  Temp Comp. probably would lower these numbers a bit.
> 
> I might try running my K3 as signal source for Temp Comp. if it holds more stable then the XG3 at 50-MHz.  I am using the EXREF so it may be better?
> 
> 73, Ed - KL7UW
> http://www.kl7uw.com
>    "Kits made by KL7UW"
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