I use four elevated radials for 80m. What I did was hook up my analyzer
to each pair, 90 degrees from one another, without connecting anything
else tune for resonance (just like a dipole, which it essentially is)
Then connect them all together to the vertical antenna feedpoint coax
connection. This worked very well, do I have equal currents in each
radial with this approach ?
Bob
K6UJ
On 2/27/16 9:32 AM, Dennis W0JX via TowerTalk wrote:
The effect of the earth on the radial generally is to detune it and make it
longer electrically than it is. Perhaps Frank W3LPL can add something here as
to why he recommends 70 feet.
As for elevated radials. many studies have concluded, going back as far as Les
Moxon, that quarter-wave elevated radials are about the worst possible length
you can make them. This particular length makes it very difficult to obtain
equal currents in each radial. Dick Weber, K5IU, wrote an excellent article on
this topic, stating that ideal lengths are 60 degrees (or about 2/3rds of a
quarter wavelength) loaded by a single small coil, or 120 degrees (about 4/3rds
of a quarter wavelength) tuned by a variable capacitor, are ideal lengths. Of
course, a multi-band vertical complicates matters and would require a loading
coil for each band.
73, Dennis W0JX
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