[Elecraft] KAT500 autotune

[Stephen Prior]

An ingenious idea but I think there is a flaw in the argument, in that at
the position of the K3's ATU there will be a different impedance to match
than is the case at the KAT500's position further along the line.  Not only
will the impedance move around the Smith Chart a bit but there is also the
input impedance of the KPA500 to consider.  Maybe in practice all of the
above may have a negligible effect, but I somehow doubt it.

73 Stephen G4SJP


On 23 February 2014 12:58, Poul Erik Karlshøj (PKA) <PKA at telepost.gl> wrote:

> KAT 01.58 is working nicely. But still, if Your antennas are changing
> impedance as the WX changes (which I can confirm is the case when antennas
> are mounted in or very close to trees :-) You are going to hear these
> sometimes lengthy clickety-clack. Even when making two configurations (one
> for dry and one for wet WX) You have all "shades" in between, so once in a
> while You are going to have the relays going crazy again. At least it
> happens to me.
> This made me think if it might be avoided keeping in mind that the K3 ATU
> does the tuning a lot less noisy.
>
> I think others have suggested a firmware change making autotune of KAT500
> initiate from the K3. This may be an interesting way to get rid of the
> clickety-clack of the KAT500 if done as follows when selecting TUNE on the
> K3 (new mode: KAT500):
> - KAT500 enter bypass (KPA enters STBY) and K3 performs the autotune
> - K3 ATU config transfers to KAT500
> - K3 ATU changes to BYPASS
> - KAT500 changes to MANUAL
> if the cables from K3 to KPA are not so good it may be that the KAT needs
> to fine tune. So a fine tune of the KAT might be a good idea.
>
> 73/OZ4UN
> Poul-Erik
>
> Sendt fra min iPad
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