[Elecraft] KAT500 AUTO vs MAN mode

[Don Wilhelm]

Chad,

This is a situation that is the result of the KAT500 useing a single 
detector for sampling the forward and reverse power.  In other words, 
both cannot be sampled at exactly the same time.

If the forward power is sampled when the power is low and then the 
reverse power is sampled when the power is high the computed SWR will be 
a higher value than actual.
This can occur with the syllabic power change in SSB, but it is also 
possible to occur with high speed CW.

The firmware developer has been working to shorten the sampling 
interval, but so far he has made improvement, but it may not be possible 
to completely eliminate the difference without hardware changes to allow 
simultaneous sampling.

The solution is to run the KAT500 in MAN instead of AUTO once you have 
'trained' the tuner to any particular antenna.

73,
Don W3FPR

On 12/10/2014 11:58 PM, Chad WE9V wrote:
> So I got my new KAT500 yesterday, and got it all trained to each of the
> segments, without reading a single reflector post on the subject (pat own
> back).  Start operating and finding that it wants to tune again in the
> middle of a QSO (CW or SSB).  (Even when the bypass SWR is 1.5)  I wrote up
> a big post to my local club to ask for help there first, when someone says
> that's common operation.  Need to run in MAN mode, not AUTO.
>
> Came here to the reflector archives (I'm not a regular reader) to see lots
> of suggestions to run in MAN mode.
>