[Elecraft] KXAT1 with dipole

[Bob Cunnings]

You don't mention on what band you were trying to get a match... 40 meters?

If so, I can relate that once in a while, my KXAT1 seems to get
"stuck" in the sense that I can't get a match even when it's a easy
scenario - such as resonant antenna fed with 50 ohm coax. I've learned
that by using TUNE at some point of the band considerably removed from
my initial freq, the KXAT1 will "snap out of it", and get a nice
match. Returning to the original freq and using TUNE again results in
a good match, and all is well.

It happened just this past weekend... I went into the field and put up
my nice portable 20 m ground plane vertical, which presents a nearly
perfect match to coax, but couldn't get a match with the KXAT1 at
14.060... odd. After checking connections, etc. I simply moved to
14.200 and got  the usual good match in just a few clicks of the
relays. Returned to 14.060 and all was well, I could re-tune at will
without trouble.

It happens rarely, and I've always been able to recover by shifting
freq temporarily - or once, by tuning into a dummy load. I've checked
by KXATI construction and alignment several times, seems to be ok.My
suspicions center on the SWR bridge and nulling, but usually it works
just fine. Maybe I'll find a cold solder joint some day if I keep
looking.

RC

On 8/22/06, Dan Presley <dpresley1 at comcast.net> wrote:
> I was out in the woods of Oregon today (up by the coast range town of
> Jewell) with my KX 1 and a few different antennas. I used a long wire
> for a while, but then for the heck of it I set up a 40M inverted vee
> with my portable mast. The KXAT1 had no trouble with the long wire
> (and counterpoises) bringing it right down to 1:1, but no such luck
> with the dipole ( cut to resonate on 40, and fed w/RG 174).I've used
> this antenna a bunch w/ the K2 and it's pretty much a 1:1, but when
> using the KX1 atu I got around 9:5 SWR! So, I promptly forgot how to
> bypass the tuner (until I got home and re-read the manual;set it to
> 'CAL':).But,also in the manual it states that it'll match most coax
> type dipoles, etc.Elsewhere it's stated that it won't match a half
> wave length,but I wasn't clear if that's only for a half wave end
> fed.I'll bet it's the same for a resonant dipole as it's a ground
> independent half wave, but maybe someone who has come up against this
> before can clarify as far as the tuner is concerned. I usually bring
> a separate antenna 'dipper' just to check the antenna in case there's
> a short or bad coax,etc., but that got left behind. Just for
> reference, I use the lightweight dipole kit from N2CX with a nice
> sealed center insulator and RG 174 (I know it's not the most
> efficient, but for a short run it's fine and very lightweight). I'm
> still trying to find more of the type of wire he used in there-it's
> springy yet has a great slick and tough coating which holds up well
> in trees, etc, It's also a light yellow in color so it blends
> nicely.N2CX quit making these kits a while back and ran out of that
> wire.The 'Wireman' sells some similar stuff,(524?) but it's still not
> the same.
> Any thought appreciated on the tuner-I'm trying to get as much
> outdoor radio time in before summer ends:)
> --
> Dan Presley-N7CQR-Portland, Or QRP-L #502 ARS #71
> n7cqr at arrl.net
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