Richard Harrison wrote:

Dave wrote:
"What would your recommendation be?"

I would use a vertical collinear omni antenna for the repeater and
vertically polarized Yagis for each of the "sheds". To avoid stimulation
of argument, I`ll say no more. You mainly need a line-of-sight path at
915 MHz between all remote sites and the repeater.

Best regards, Richard Harrison, KB5WZI


Motorola 900 Mhz Canopys are advertised as "non line of site", so you
may get more mileage than you'd expect when running at this relatively
low frequency. If you are looking at paths that can be well defined,
try a program called "Radio Mobile" for a very good simulation of the
situation. It is freeware, and the databases it uses are also free
(courtesy of the US taxpayer and some hardworking US Shuttle astronauts
and groundcrew).

tom
K0TAR

Tom Ring wrote:
"Motorola 900 MHz Canopys are advertised as "non line of sight"... so
you may get more mileage than you`d expect when running at the
relatively low frequency."

It`s true that radio does not always take a direct path. Part of ham
radio fun is in anomalous propagation. It`s also true that the higher
the frequency, the smaller the obstruction that can block propagation.

900 MHz is more reliable than frequencies in the GHz. A point to
multipoint system may require more reliability than a single point to
point system, and more reliability than: "Can You believe it? I`ve
contacted DX!" I`ve engineered and installed several 900 MHz systems
which proved to provide, with their path clearances and fade margins,
24-7 reliability of very nearly 100%.

Line of sight is defined as: "The distance to the horizon from an
elevated point, including the effects of atmospheric refraction."
Another definition is: "The propagation characteristic of microwave
radio."

900 MHz is on the border between UHF and microwaves. It shares some of
the characteristics of both.

Best regards, Richard Harrison, KB5WZI