[Elecraft] KAT500 and SWR

[Ron D'Eau Claire]

Phil, did you try a "fine tune" after the first tuning (tap TUNE again
within 5 seconds after the KAT500 stops a tune operation)? That will cause
the KAT500 to choose finer steps of L and C in a search for the lowest SWR
(See "Fine Tuning" in the manual). 

73, Ron AC7AC

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Phil Hystad
Sent: Wednesday, December 05, 2012 9:40 PM
To: Elecraft Mailing List
Subject: [Elecraft] KAT500 and SWR

I am having trouble getting a reasonably low SWR on the 80-meter band with
the KAT500.  Maybe someone can help by confirming that this is the best I
should expect or maybe give me hints to see if something better is
achievable.

On the frequency 3.569 MHz I regular operate each evening on a CW Net.  My
best SWR from the KAT500 has been around 1.75:1 and tonight the best I was
able to achieve was 1.99 to 2.01 to 1.

Yet, using my other manual tuner, my Palstar AT1KM, I easily tune to a 1.0:1
SWR, absolutely flat.

Another puzzle is that I can get a descent SWR on another much used
frequency (3.975 MHz) of about 1.25:1. But, on the AT1KM I can also easily
achieve a 1.0:1 SWR.  Indeed, the tuned position for inductor and capacitor
for the 3.569 and the 3.975 frequencies are not too far apart on the AT1KM
but the KAT500 really struggles to get an SWR below 2:1 and half the time it
does not.

Note:  all of my SWR readings are measured by multiple devices that all
indicate similar readings and the KAT500 I am also using the KAT500 Utility
to see the SWR and it is very close to my other readings so I am fairly sure
these SWR values are reasonably accurate.

Has anyone else had trouble using the KAT500 to tune an antenna to a
particular frequency where other manual tuners have had an easy time at it?

I appreciate your comments and suggestions.  By the way, no problems at all
on all other bands and testing using two different antennas.  It seems the
only problem is on the low end of the 80 meter band.

73, phil, K7PEH

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