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

[Michael E. Dobson]

Don,

I am experiencing the same or a very similar problem as Marcin.  It 
only happens on 17M and only at high power.  That is why we do not 
see it after a Tune operation.  If I turn the power down to 30W or 
less, no problem.  It makes no difference whether the KPA100 is the 
top cover or remoted in an EC2 with the KAT100.  I haven't determined 
exactly how much power I have to be running before the problem 
occurs.  I suspect RF getting somewhere it shouldn't but have not had 
the time to track it down.  It does seem to be antenna dependent even 
though I get a good match to the 102 foot doublet I use.  I will get 
a chance to test my theory next week when I take the K2/100 portable 
for a week using a different antenna than I do at home.  If it occurs 
only at the home QTH then the problem is in the antenna system and 
probably stray RF affecting something in the K2.

73,
Mike K2/100 #2221

At 01:31 PM 9/6/2006, Don Wilhelm wrote:
>Marcin,
>
>There is nothing in the KPA100 or the base K2 that would cause that problem
>on 17 meters only.
>In the base K2, the relay switching is shared for 17 and 15 meters except
>for relay K6 in the bandpass filter, and in the KPA100, all circuits are
>shared between 17 and 20 meters.  You would have a problem on either 20
>meters or 15 meters in addition to 17 meters if it was associated with
>either the K2 or KPA100 switching relays.
>
>If you have a dedicated 17 meter antenna, you may want to investigate the
>switching to that antenna.
>
>TUNE should behave the same as transmit, but you say that receive
>sensitivity does not drop after TUNE - that is indeed strange.  We need more
>data.
>
>73,
>Don W3FPR
>
>
> > -----Original Message-----
>
> > Hi all,
> >
> > In last Friday I have been finished KAT100/KPA100 in EC2.
> > Few days ago one problem occurred - before TX on 17m RX is OK, after TX on
> > this band RX dropping down. This is only on HI power range, on LOW
> > power range everything is OK.
> > When I change band to other then 17m and then come back to 17m RX stay
> > OK to the TX and then drop down again. When I Off then On K2 or push
> > TUNE key, RX come back to normal.
> > Is anyone know what is the problem?
> >
> > 73,
> > Marcin SQ2AF
> >
> > K2 #5408
> >
>
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