Sun noise
"Jeff" wrote in message
. com...
I would like to see what mods are made to the 221 to do that and also
what kind of antenna system. I have a 221 I am using with a gasfet
preamp in the shack that should be less than 1 db of noise fugure and
about 20 db of gain. The antenna is a klm 22c and 75 feet of 9913 type
of coax. I can just see some sun noise with the antenna aimed at the
sun. It sure does not deflect the smeter several sunits. The antenna is
on an azel mount. I am sure the system is working as I compaired it to
an Icom 706 and another antenna that is mounted on a tower and I am
getting about the differance in signal levels I would expect at the
horizon.
The 75 feet of coax is your problem!!! What is the point of a 1dB NF
preamp with all that loss ahead of it? To see the benefit of the low noise
figure the amp must be before all that cable loss!!
73
Jeff
G8HUL
The coax only has a loss of 1 db for the length I am running it. I doubt
that at 2 meters I would see any benift of putting the preamp at the
antenna. It is as easy to get a 1 db or less noise figure at 2 meters as it
is to make any preamp and the 221 does need some help on the receiving side.
From the articals I have read the beam width of most any single antennas at
2 meters is wide enough the ground noise will override that ammount of loss.
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