On Mon, 31 Oct 2005 05:57:39 -0500, Al Klein
wrote:

On Sun, 30 Oct 2005 15:27:34 GMT, "Jeff"
said in rec.radio.scanner:

"Al Klein" wrote in message
Four things you should be aware of:

1) A discone is a negative gain antenna - that is, it has less gain
than a dipole, which is the standard by which 0 gain is measured.

Name 1 "scanner" antenna that does have gain? Not an
amatuer antenna a "scanner" antenna.

Since we never covered "scanner antenna" in antenna theory, define
what you mean.

Dipoles (or ground planes) have, by definition, 0dbd gain.
Incorrect, gain is normally quoted over an Isotropic radiator, which a
Dipole is NOT. However relative to an isotropic radiatior, and
Discone is a zero gain antenna. The attraction of the Discone is from
the low VSWR over vast frequency range. A very high VSWR can turn a
high gain antenna into a losing proposition because of feedline
losses.

A discone
has negative gain, vis-a-vis a dipole.
T

On Mon, 31 Oct 2005 17:26:18 -0700, matt weber
said in rec.radio.scanner:

On Mon, 31 Oct 2005 05:57:39 -0500, Al Klein
wrote:

Dipoles (or ground planes) have, by definition, 0dbd gain.

Incorrect, gain is normally quoted over an Isotropic radiator, which a
Dipole is NOT.

Normally advertising hype is quoted in dbi, while honest antenna gain
is quoted in dbd. So is engineering gain.