[Elecraft] KAT500 and SWR

[Ian Kahn]

Phil,

What is your untuned SWR on your antenna(s) at those frequencies, and how
much power are you running?  If I remember my readings correctly, if you
get above the 500W nominal power rating of the KAT500, by design it will
only match a "native" SWR of about 3:1.  Others on the list who are more
knowledgeable, please feel free to correct any factual errors I may have
made.

Thanks and 73,

--Ian
Ian Kahn, KM4IK
Roswell, GA  EM74ua
km4ik.ian at gmail.com
K3 #281, P3 #688
HRD v5.x/6.0 Test Team

On Thu, Dec 6, 2012 at 12:40 AM, Phil Hystad <phystad at mac.com> wrote:

> 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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