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Re: KAT2 with EFHW antenna

Posted by stan levandowski on Aug 24, 2011; 4:08pm
URL: http://elecraft.85.s1.nabble.com/K3-S-meter-oddities-tp6676870p6720781.html

Ron, the one I purchased for $42 is for 20 meters and came with a 33
foot radiator.  A mathematical half wave at 14 MHz would work out to
32.8 feet.  It did not come with a counterpoise nor was one recommended.
It loaded up nicely for me as received.  I later tried a short
counterpoise and did not note any difference in performance.   I use a
short coax of about 12 feet for portable work.  It seems to work very
well and only having to worry about hanging one end is convenient.  And
the wire is a nice quality that resists tangling.

The documentation that came with mine warned that for 40 meter use, I'd
need to replace the radiator with a 66 foot length and a wing nut
arrangement is provided for that.  I've never tried it on 40 meters.

Ron, I'm no antenna expert (hence "more money than brains") but I'd like
to add that the precursor to this EFWHA came right out of the KX1
documentation.  It's just a double BNC connector with a 28' radiator and
a 33' counterpoise.  I moved to the EFHWA because I got tired of
untangling the two wires.

In a side by side test, both antennas sounded the same to my ear.  I
retired the double BNC affair in favor of the EFWHA because I figured
the EFWHA was a more efficient radiator, as you pointed out.  Something
my ears wouldn't necessarily disclose to me.

I apologize for not having re-read the material on those links I
provided.  Apparently something has changed since I purchased mine.

73, Stan WB2LQF


On Wed, Aug 24, 2011 at 11:06 AM, Ron D'Eau Claire wrote:

> Stan, that's not a true half wave radiator on most bands. They suggest
> a
> wire length of 20 or 30 feet, which will be efficient on 12 through 6
> meters
> where it's at least 1/2 wavelength long, but on the lower frequency
> bands
> it's just a short random length wire with an auto-transformer to
> assist with
> impedance matching.
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