In article , wrote:

With a dipole, you are depending on the null to minimize the undesired
signal and have little gain in the direction of the desired signal.

With a yagi, you still have the null (assuming a proper yagi) plus
additional gain in the desired direction. The net result is the ratio of
the signal strengths of the desired to undesired signals becomes greater.

Agreed. With a Yagi one might get the best desired-to-undesired
signal strength ratio by pointing the antenna somewhat to one side or
the other of the transmitter. This could reduce the "desired" signal
somewhat, but could put the "undesired" signal path right in one of
the antenna's deep nulls. Most Yagis having a modest number of
elements have a wide-enough beam angle to give you a fair amount of
wiggle-room in the aiming.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
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Dan Jacobson wrote:
Assume there is only one spot on your hilly land that you can pull in
your favorite FM station, 90 Mhz, over the competition, and only with
a horizontal dipole at a certain azimuth. A Yagi doesn't help, as
we are depending fully on the null.

Assuming we are stuck with this position, how can we enhance our
dipole? I am the owner of great sheets of metal. Can I put my great
sheets of metal to use in e.g. a dipole made of two great sheets of
metal?

I should have probably also mentioned that making a dipole from
sheet elements mostly effects the bandwidth and has very little
effect on either the gain or the pattern.

Search the web for bat wing antenna for more info.

--
Jim Pennino

Remove -spam-sux to reply.

Dan Jacobson wrote:
"A Yagi doesn`t help, as we are depending fully on the null."

Dan also wrote:
"I am the owner of great sheets of metal."

If "your favorite FM station, 90 Mhz," differs in direction from its
interfering "competition, and only with a horizontal dipole at a certain
azimuth", a Yagi made by adding a director and a reflector should
increase signal to noise ratio.

Great sheets of metal can be used as a corner reflector for a favored
dipole. A 90-degree reflector can give about 10 dBd gain. A 60-degree
reflector can give about 2 dB more gain than the 90-degree reflector.

J.D. Kraus documented the corner reflector, Proc. I.R.E., 28, 513-619,
November 1940. Consult Kraus, "Antennas" for complete information, 1950
edition, page 328.

Best regards, Richard Harrison, KB5WZI