"Ralph Mowery" wrote in message
...

"Jerry Martes" wrote in message
news:%dsZi.2897$CI1.289@trnddc03...
Although I disagree with your premise about "great distance and a few
hundred miles", I must admit that I lack knowledge of the satellites
other than the few NOAA satellites. The NOAA satellites are about 4
time more distant at the horizon than overhead. That results about 12 dB
less signal at the low elevation angle. The 12 dB is fairly easy to put
back in the plot.
The guys at NASA/NOAA did an excellent job of tailoring the NOAA
satellite pattern shape so it is close to equal over the entire pass. I'd
have expected the "OSCAR" guys to have done the same and shaped their
satellite antenna beams to be essentially equal level over the angle at
which the Earth intercepts the satellite beam.
I'd like to know more about a 2Meter beacon satellite. Can you point
me to a site where I can learn about 2Meter beacon satellites? I have a


Jerry you can find information on the ham sats at www.amsat.org.

I guess the great distances I was thinking about was from about 200 miles
to around 1000 or so. As you said that is getting close to 10 to 12 db
differant. In one way that is not really that much differance in signal,
but the types of antennas we have been talking about would have from 0 db
to about 6 db of gain. Most would have just one or two db worth of
differance in the best direction.

Hi Ralph

I would sincerely like to know where to find that 2Meter beacon from a
satellite. I have searched a little. Since you have knowledge of the
satellite with the 2Meter beacon, I'd appreciate any link to it. I have
some AMSAT journals but I havent recognized which satellite transmits that 2
Meter beacon.
Your posts show clearly that you question the accuracy of the radiation
pattern measurement of an antenna when the satellite is used for the
illuminator. I submit to you that you wont find a better way to record the
actual radiation pattern. I can measure an antenna's pattern with close to
20 dB dynamic range. It is unclear to me why you doubt the accuracy of
patterns I record.
One of the benefits of using 137 MHz is the ease with which a person is
able to find programs that tell the exact location (Az - El) to the
satellite. You can se an example of the radiation pattern at Patrik Tast's
site http://www.poes-weather.com/. The pattern is in the section
"antennas".
I sure will appreciate any information you can give me related to 2Meter
beacon satellites. I'm trying to make a program (free) that amateurs can
use to record 2Meter antenna radiation patterns. I am very pleased with
the program Patrik made for me using the 137 MHz satellites.

Thanks for your help
Jerry