[Elecraft]Low Dipoles (WAS: Buddipoles and KX1)

[Ron D'Eau Claire]

A lot depends on who you want to work and if you can configure your
"hamstick" is configured for vertical or horizontal polarization. A low
dipole make a good short skip ("NVIS") antenna where a vertical has little
high-angle radiation. 

The disappointment with a vertical usually comes from the fact that avoiding
the high angle radiation does NOT mean more low-angle radiation! Ground
losses kill virtually all signal near the horizon, unless you're on salt
water. The end result is that the vertical may not have any more radiation
at lower elevations - say 20 to 30 degrees - than a dipole. Where the
dipole, one dipole down close to the ground, is different is that the ground
works as a reflector to produce a high angle radiation lobe. On a vertical,
that RF simply warms the ground with much higher RF currents thanks to the
difference in polarity.

Even if you only have one Hamstick, try it mounted horizontally with the
"radial" running off in the opposite direction, horizontally. You might be
quite surprised! 

Ron AC7AC



-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of John Harper
Sent: Thursday, April 17, 2008 2:14 PM
To: Elecraft
Subject: [Elecraft] Buddipoles and KX1


Mike / KK5F:
>I often erect at least two antenna types at a site for side-by-side 
>comparisons.  That is the *only* way one can determine how one antenna 
>performs against another under otherwise identical site and

I'll be doing that myself next Saturday during QRPTTF. My main antenna will 
be an 80m dipole fed with 450-ohm ladder line (for use on 20 & 40m with 
tuner) that I want to compare with a camera tripod-mounted hamstick on 20 
and 40 meters. I already have an idea how they will compare - the only 
reason for the test is that I have a camping spot in mind for some time in 
the future where there are no "organic supports" for a dipole and any radio 
operation will necessitate a small vertical as described. I just want to 
know how much more poorly the vertical will be. I plan to have four 33' 
radials for it. The dipole will be up about 40 feet & the rig will be a KX1.

John Harper AE5X
http://www.ae5x.com




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