K7MEM wrote:
A 15 foot long boom would support 1 Reflector, 1 Driven Element, and 5
Director elements. This would give you a estimated gain of almost 10 dBd.
Normally the bandwidth of these antennas is about 7% at the design
frequency.
For your use this would be about 6.5 MHz. If you are only interested in a
small portion of the band, this will work fine.
SNIP
Optimization is nice to do if you have the equipment, but with careful
construction, you should be able to build a antenna that is very close to
the intended specifications and not require any tedious tweaking.
For other antenna designs you might try Ian White's (G3SEK) web site at:
http://www.ifwtech.co.uk/g3sek/diy-yagi
If your intent is to cover the entire FM band, you may want to look for
information on Log-Periodic antennas. Gain will not be big, but the
bandwidth will be.
There is a 10 foot boom KLM driven element style yagi in the YO yagi
collection supplied with the program that is 75 ohms and claims 20%
bandwidth. I'm sure there are several here that could supply that
design, or run it again with more boom and elements. Or possibly
someone could run it under AO with more than 3 optimization frequencies,
which may be more desirable yet.
tom
K0TAR