[Elecraft] Subject: Re: 2 meter EME considerations with the K3

[Edward R Cole]

There are two sources of frequency drift: the TCXO of the K3 and the 
LO of the transverter.
The combined error determines the final frequency stability.

Upgrading to the TCXO-3 improves K3 frequency stability by 
ten.  Adding the EXREF board improves this.

To improve the transverter LO, it would be best to use an external 
LO.  One could build a stable xtal LO or use one of the PLL synth 
boards that I mentioned in an earlier post.  This is not as hard as it sounds.

If you are considering 2m eme this WILL be important.

I run the K3 with TCXO-3/EXREF and my 50w transverter* has 6-Hz drift 
after 30-min of running JT65.
*Not a XV144

73, Ed - KL7UW
-----------------------------------
I don?t believe the external transverter?s frequency stability is any 
better if the K3 has the TCXO option.

I owned an XV144 without the optional TCXO option which I attempted 
to use with meteor scatter, and was very frustrated by its constant 
frequency drift.  After I installed the TCXO in the transverter, the 
frequency was slightly more stable, but still not useful enough for my purpose.

Elecraft told me their external transverters are an older design 
which they admit do not maintain the frequency stability necessary 
for the JT modes.

73 de Sebastian, W4AS


73, Ed - KL7UW
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