[Elecraft] KAT500 and SWR

[Phil Hystad]

The Bypass SWR is about 7.6 (as read off the KAT500 utility program).  Dick, K6KR, the author of the Elecraft utility programs (on the Windows side at least) gave me some ideas on how to do a manual tune using the utility program.  I will try that tonight.

Also, this 1.99 to 2.01 tuned SWR is at 25 watts, no KPA500 in line when I operate at that frequency -- that is, CW in a northwest area net so no need.

phil

On Dec 6, 2012, at 5:50 AM, Ian Kahn <km4ik.ian at gmail.com> wrote:

> 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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