[Elecraft] KX2 Antenna Curiosity

[Don Wilhelm]

Shu,

If you add the 58.5 foot wire to the 16.5' counterpoise, you have a 75 
foot antenna.  That is close to a half wavelength on 40 meters.  You are 
feeding it off-center which will allow it to be used on several bands 
(even though one of the antenna wires is on the ground).
As I recall, Bruce Prior (one of the KX2 Field Testers) recommended 
those lengths for 40 meters thru 10 meters.
If you feed those 2 wires directly from the KX2 tuner using a BNC to 
binding post adapter, you do not have to worry about feedline loss - 
there is no feedline!
If you do use a feedline, I suggest ladder line rather than coax because 
it will not have as much loss in the feedline due to an impedance mismatch.

The KX2/KX3/K3 ATUs have a very wide matching range and this antenna 
will work fine with any of their tuners.

73,
Don W3FPR

On 10/10/2019 12:01 PM, Joseph Shuman via Elecraft wrote:
> I have had my KX2 with the ATU for about 10 months and operate on 40m QRP SSB from various locations.  Experimenting with different antennas I have experienced best results with a 58.5’ wire tossed about 25’ up a tree with a 16.5’ counterpoise.  I ran the same length wire from my house to the workshop, grounded the shield side of the cable, and have seen similar results to the field setup.
>