[TowerTalk] Elevated vertical

[Tom Rauch]

> Joe, the way I do elevated radials is to tune them
slightly lower than the operating frequency... This is
easily done... Put up the first two and drive them as a
dipole and tune to the desired frequency...   Make the other
two the same length...

The only way I know of to make sure a radial is resonant is
to feed it like a dipole against another radial of equal
length.

I can't think of any reason to not tune it to the center of
the band, since doing that would ensure lowest feedpoint to
ground voltage on the radials.

Elevated radials SHOULD have the feedpoint decoupled through
a common mode choke. if you ground the radial common point
is causes increased loss as well as current on the feedline
shield.

Conventional systems offer greater bandwidth and just as
good or better efficiency. You do need a bit more wire, but
it is significantly less critical what you do with the wire.

Reliable FS measurements have shown eight resonant radials
at 1/4 wl above ground are about equal with sixty radials on
the ground.

My own FS measurements both here and in Conyers GA showed
four elevated radials at six feet height on 80 meters are
down about 5 dB or more from sixty radials laid on the
ground. At WVNJ six radials at 20-30 feet high were down 2.5
to 4 dB from  60 radials on the ground, depending on the
measurement point.

I hope everyone against me in a pile up uses four (or better
yet two) elevated radials.

73 Tom