[Elecraft] K2 problem or is it the antenna?

[Don Wilhelm]

Kieth,

If the K2 works fine into a dummy load - and some of your antennas, then the
problem is not with the K2!

You likely have a piece of coax (or antenna) that is failing with power - it
could be an arc-over situation or something like that.  Try moving the dummy
load to the garage first, then on out ot the antenna.  If the dummy load
works fine at those locations, it is not the coax, look at your antenna for
the problem.

The fact that the resonant frequency shifts on you says the most likely
place for the problem is the antenna, but coax can act like a tuned circuit
too, so check it all.

73,
Don W3FPR

> -----Original Message-----
>
> My K2 will not give more than a few watts out on 40 meters when driving
> my antenna.  Into a dummy load it gives full power.  On 30 meters with a
> different antenna the rig is fine.  I wondered if it was a problem with
> the rig but I saw some other things that make me think it's an antenna
> problem.
>
> The antenna is a ground mounted vertical fed with 30 feet of RG-213 to a
> Heath manual tuner in the garage.  From there, RG -8x takes the signal
> all the way to the shack.  I go to the garage with my MFJ analyzer and
> adjust the tuner for a match on my operating freq.  I did this and got a
> 1:1 match at 7040.  I then went to the shack and confirmed the same SWR
> at the rig.
>
> Hook up the rig, key it and the SWR meter shows very high SWR.  Rig is
> generating hardly any power out.  Recheck with the analyzer and SWR is
> fine.  Hmm.  I'm thinking the issue is power related.  Could it be that
> my antenna system has a problem that only shows up when you hit the
> system with a few watts and doesn't show when the analyzer hits it with
> milliwatts?
>
> Last night I tried it again and noticed the resonant frequency had
> shifted from 7.040 to 9 MHz.  I think it is time for an antenna / tuner
> / coax review.
>
> - Keith -
>