On Tue, 13 Sep 2005 10:04:26 -0400, Cecil Moore wrote:

KC1DI wrote:
The clssic Quad loop is a good single band antenna , you could feed it
with coax as well. (75 ohm) The impeadence is about 125 ohoms. It
will have on the order of about 1 to 3 db of gain over a dipole
bi-directional.

Hi Dave, I'm interested in knowing how you get the gain of a
quad loop to equal the gain of an Extended Double Zepp dipole?

Hi Cecil,

Good Question.. I should have been more specific.. the gain of a fullwave
vertical loop over a 1/2 wave dipole is approximatel 1.2 db-- if you use
the same antenna on the 2nd harmonic you will get about 3 db gain , but
with that said we must realize that this gain is not necessarily at good
angles for DX. The dipole may actually have a better pattern that a 2
wave vertical loop. and thus any gain achieved will be negated by the
fact that this gain is at angles that are not conducive to good Dx
propagation.

Cebik places the gain of a full wave vertical loop at about 5.9 dbi that
rises to about 7.6 dbi on the 2nd harmonic and about 8 dbi on the 4th
harmonic.

But the T.O. Angels are as follows-- Fundamental Frequency- 35 deg. 2nd
harmonic 48 degrees 4 harmonic 45 degrees This is for a square loop.
these are not great figures for DX but useable none the less. A Dipole
would though I have not researched it do better in the angle department.
thus any gain received by the loop would be negated but a stornger signal
at the right angle by the dipole.

73 Dave


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