[Elecraft] Problem with 17m band in K2 + KAT100/KPA100 in EC2

[Don Wilhelm]

Marcin,

Now that you know where to look for the origin of the problem, I am
confident you will correct it.
Stray RF does many strange and unexpected things.

73,
Don W3FPR


> -----Original Message-----
>
> Don,
>
> Yes, yes, you are right! - it is caused by stray RF.
>
> I attached counterpoise wire cut for a quarterwave on 17 meters and it
> resolve the problem.
> Now, with your help, I'm sure that my K2 and KAT100/KPA100 are OK and
> my problem is antenna. So, I must go to the roof, recheck antenna
> connections and realign it.
> Thank you again for your help!
>
> 73,
>
> Marcin SQ2AF
>
> K2 #5408
>
>
>
> 2006/9/8, Don Wilhelm <w3fpr at earthlink.net>:
> > Marcin,
> >
> > I checked the RigExpert specifications, and while they claim
> isolation on
> > the soundcard connections, they do not make any such claims for
> the digital
> > connections (to the PTT, CW Key, or AUX I/O).
> >
> > So you still may have a problem with RF getting onto the
> RigExpert or the
> > computer chassis ground that is being then transmitted into the K2.
> >
> > This is not a problem with your connections, but it may be a
> problem with
> > the RigExpert on your K2 in combination with your antenna
> situation.  I am
> > not yet convinced that it is a KPA100 problem.
> >
> > If you can test it with the KPA100 working into a dummy load,
> that would be
> > of interest, but it may be hard to detect if your receive is
> desensitized
> > with the dummy load connected.
> >
> > If you do not have the K2 mic jack shell grounded, you could
> try doing that
> > as a first measure of defense.
> >
> > The other thing you can try is attaching a counterpoise wire cut for a
> > quarterwave on 17 meters to the KAT100 ground.  The far end may
> carry a high
> > RF voltage, so keep it clear of human and pet contact (the far
> end connects
> > to nothing - just an insulator).  If a counterpoise wire corrects the
> > problem then you can be certain it is caused by stray RF -
> unfortunately, if
> > it does not cure it, stray RF could still be the problem, but
> it is worth a
> > try - a piece of wire an electrical quarterwavelength on 17 meters is
> > approximately 3.9 meters long.
> >
> > 73,
> > Don W3FPR
>