[Elecraft] KAT500: Tuning on 6m

[Jim Brown]

On 7/14/2013 4:43 AM, KD7YZ Bob wrote:
> On the KAT500 I can press 'TUNE' then tap K3 "XMIT" and the KAT500 will
> usually settle on or about 1.1:1 .

I've never run into this problem, and I've used it a lot on 6M. There is 
a menu setting that may help (or cause) your problem. I don't recall the 
exact wording, but it establishes the upper limit on SWR for which the 
tuner should be in bypass mode. In other words, if the SWR is below 
1.5:1, the tuner should go into bypass.

> Then when I .run a WSJT, Data, QSO, if the KAT500 is left in "AUTO",
> re-tuning will often take occupy 10 or more seconds of the time before
> the KAT500 finds a place it likes. Often the SWR is then in the RED or
> worse, FAULT. Not very often on FAULT however.

A couple of suggestions though.  First, the SWR through the ANT1 port is 
slightly lower than through the ANT2 and ANT3 port (although all three 
are quite low).  Second, it's worth the time to check every element of 
the path to that 6M antenna, looking at every connector, everything in 
line (SWR meter, antenna patch panel, grounding panel, etc.). Make sure 
that EVERY connector in the path says AMPHENOL on it, and that it is 
wrench tight.  Junk connectors are a huge cause of problems -- I'm 
talking PL259s, barrels, adapters, tees, elbows. Make sure that every 
cable-mounted connector is properly installed. Those shiny adapters sold 
at hamfests, and in the back of the magazines are JUNK.  Make sure that 
none of that cable has gotten wet, which will degrade the shield.

This is first-hand advice. I've personally experienced at least a half 
dozen problems with junk connectors over the years, and everything in my 
system now either says Amphenol on it, or is surplus MIL-spec stuff. 
When I installed my KPA500, put switches at input and output so I could 
run either the KPA or a legal limit Ten Tec tube amp, and had both a 
power meter and a scope probe in line. The resulting SWR as displayed by 
the KPA500 was approaching 2:1. I cleaned up the mess (installed much 
better switching relays, removed the power meter and scope probe, found 
a bad cable or two) and got the SWR down to the 1:1:1 value that I 
measured at the grounding panel.

73, Jim K9YC