[Elecraft] KX1 ATU Antenna Length Question

[Rick Hampton]

Hi, Rich.

I'm using either a 26' or 42' wire, depending on the support available.  The 26' wire
seems to be more persnickety when tuning, but I don't think I've ever seen a VSWR
above 2.0, it just takes a little longer to tune.  The 42' wire seems to tune faster
and the VSWR is nearly always less than 1.5.

Your wire might be a little short, but since I've not had any problems with the two
wires I have, I've not experimented enough to be certain that is the case.  In other
words, I'm not sure I've pushed the ATU to the limits of it's matching ability.  You
may just want to try a longer wire and see what happens.

Good luck and let us know what you find out.

Rick, WD8KEL
KX1 #358

Rich Patrick AE7RW wrote:

> To the KX1ers......
>
> I sailed my KX1 [#422] on it's maiden voyage last evening for the
> Adventure Radio Society's Spartan Sprint.  Operated at the picnic table
> in
> the back yard.  I used the recommended wire length for the KX1
> Automatic
> Tuner:  about 25 ft with 16 ft counterpoise wire.  The antenna wire was
> made vertical with a 23 ft.  fiberglass push-up pole to simulate
> "throwing the wire up in a tree".  The KX1's ATU is calibrated
> correctly
> against a precision dummy load for SWR.
>
> 14 MHz  started out great.  SWR was 1.0  per the ATUs watt/swr meter.
>
> 7 MHz   doesn't tune so well.  SWR was 4.x.   So I went to 10 MHz.....
>
> 10 MHz measures about SWR of 3.x  I quickly tried to shorten the wire a
> few feet (cutting the wire in the dark was easier than lengthening
> it).... to see if the SWR was better...NOT.  So I gave up the outside
> operation... went inside to the BIG RIGand made some very nice Q's.
>
> My question to the group is:   Has anyone else had trouble tuning on 7
> MHz [and 10 MHz] with the recommended "throw it in a tree" wire length?
> If so... what wire length did you find to be best.... for all bands.
> ??
>
> Thanks          de Rich  AE7RW      KX1 #422       dit dit