[TowerTalk] best coax/receiving

[k6ll@juno.com]

I conducted a little experiment around midnight last night
to see just how much background noise I had on 10 meters,
just to make sure I wasn't missing something through my
cheesy RG-213 coax.

I listened to the background noise in AM mode. It sounded
relatively "white."

I rotated the antenna around to where the noise was minimal,
but it didn't make much difference.

The noise did not illuminate any LED's on the TS-850's bargraph
s-meter. The meter is quite generous.

I cranked in 6dB of attenuation on the TS-850, and the audible
noise went way down. I then cranked in 12 dB more attenuation,
and the noise went down a lot more. Then I removed all the
attenuators, and of course the noise came way back up.

Then I cranked in 12 dB of attenuation and the noise went way
down. Then I cranked in an additional 6dB of attenuation, and
the noise didn't change. I repeated this test using the TS-850's
AIP function, which is supposedly 10dB of attenuation. The noise
just barely changed when I cranked in more attenuation.

I believe this is telling me that, with the existing conditions
in my neighborhood, on a dead band, at midnight, I had about a
10 dB margin of atmospheric noise before I began to be limited by
the receiver. I could have been using 300 feet of RG-58 and it
wouldn't have made any difference in my ability to receive a weak
signal.

I really envy you folks who have such a quiet location that you
have to use hardline for receiving. If I had a location like that,
I might be able to win a contest once in a while.

73

Dave Hachadorian, K6LL
Yuma, AZ
K6LL@juno.com





















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