[BC] Long wire antennas

[RichardBJohnson at comcast.net]

If truly a long-wire, and end-fed against ground, it is directional
as a cone-shaped pattern with the cone about a 30 deg angle
off the far end of the wire, with no radiation exactly off
the end (a hollow cone).

A true long-wire is many wavelengths long, so that at its
far end, all the RF has been attenuated by radiation so
adding more wire does nothing. As they get shorter,
the pattern becomes more like a cardioid as it becomes
a broadside array, at which time you can feed it at
its center, becoming a dipole.

Most "long-wire" antennas are really "random-wire" antennas
which are too short for the 30 degree directivity and therefore
have a pattern which has a broadside lobe, slanted opposite
the direction of its feed.

--
Cheers,
Richard B. Johnson


  -------------- Original message ----------------------
From: Earl Fleer <e.fleer at yahoo.com>
 > Question for those familiar with the old "long-wire" antenna used in
 > early AM.  Where they directional?  What station was the last to use
 > such an antenna?