RE: KAT100: Strange K2/100 Behavior During Tune

Posted by Don Wilhelm-3 on Sep 17, 2006; 4:48am
URL: http://elecraft.85.s1.nabble.com/KAT100-Strange-K2-100-Behavior-During-Tune-tp393891p393895.html

Raj,

Fine analysis, but consider that the K2/100 has more gain and better
efficiency on 40 meters than on most of the other bands, so the current
drain on 40 meters should be less for any given power output level, and
under normal operating conditions, the current drain should be at a minimum
on 40 meters.

I fear that the power supply shutdown may be a result of some kind of
parasitic that happens when the KPA100 is set for 40 meters.  For some
unexplained reason, this shows up most commonly with the KAT100 attached.

There may be more later, I understand that the design engineers at Elecaft
are currently working on this, so patience is called for - it will likely be
corrected when all the "I"s are dotted and the "T"s are crossed (soon).  In
the meantime, Tom Hammond has compiled information on this behavior - see
www.n0ss.net  - look for the file on 'KPA100 40M Parasitic circumvention'.

73,
Don W3FPR

> -----Original Message-----
>
> Here is another simple explanation.  Perhaps it is voltage drop on
> your power supply.  You probably have the best match and most power
> output on the 40m band,  Is your power supply up to it?  A simple way
> to test this is to turn the power out down by 30W or so.  Not enough
> db wise to make a difference if it is an rf interefence issue but
> will considerably reduce the demand on your power supply.
>
> Raj, N2RD
>
> On Sep 16, 2006, at 5:20 PM, Jonathan Taylor, K1RFD wrote:
>
> > In this case the antenna is a simple coax-fed 40M dipole with a
> > balun at the feedpoint.  Without the KAT100 in line the SWR is
> > approx 1.2 to 1 at 7100 where the problem occurs.
> >
> > A quick check shows that yes, the problem seems to occur only on
> > 40m.  I also noticed that other accessories on the same power
> > supply re-set themselves when it happens, supporting the foldback
> > limiting theory and the work-around that Tom posted and Mark
> > pointed out.  However, it happens only when the KAT100 is in line;
> > I cannot reproduce it at any frequency or power level when the
> > KAT100 is disabled.
>

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com