[Elecraft] Choke for QRP with unbalanced antennas?

[Victor Rosenthal 4X6GP]

The problem occurs when the counterpoise doesn't provide a low impedance 
path for RF. If the problem occurs on a specific band, then try a 
counterpoise that is about 1/4 wavelength long on that band. You can add 
one in addition to the existing counterpoise, if that one is working 
properly on the other bands. You might have to play with it because the 
appropriate length of a wire lying on the ground will not be the same as 
one in the air.

Regarding ratings, you are lucky if "100w CW" actually means 100 watts 
at 50% duty cycle! It certainly doesn't mean 100w continuous.

73,
Victor, 4X6GP
Rehovot, Israel
CWops #5
Formerly K2VCO
https://www.qsl.net/k2vco/
On 20/11/2021 20:09, Julia Tuttle wrote:
> Hi folks,
> 
> I was tinkering with a whip + counterpoise antenna connected to my KX3 by a
> short stretch of coax with BNC connectors a couple nights ago, and
> discovered (painfully) that there was quite a bit of RF coming back along
> the ground when I bumped the outside of the antenna connector. I know from
> experience that the KXPD3 can end up tingly in turn, and I'd like to avoid
> that.
> 
> If this were a fixed antenna, I'd just slap one of the LDG RU-1:1 ununs on
> it as a choke, but they're pretty chunky -- they're rated for 100 W CW, and
> have SO-239 connectors, which would require adapters on both sides in this
> setup.
> 
> Does anyone know of a choke more appropriate for this kind of setup? I'd
> prefer something smaller (rated for maybe ~40-50 W continuous?) and
> natively BNC, so I don't need to juggle adapters.
> 
> More broadly, is this the appropriate way to fix this problem? This was
> with the counterpoise extended as best I could, and with the radio powered
> from mains (which may have actually made the problem *worse* by providing a
> more attractive path than the counterpoise?).
> 
> (As an aside, when components like baluns/ununs or tuners are rated as "100
> W CW, 200 W SSB", do they mean literally a continuous wave, or do they mean
> CW at a standard Morse duty cycle of roughly 50%?)
> 
> Thanks and 73,
> 
> Julie