> Behalf Of km1h@juno.com
Just a
> steady roar
> >the
> >full width of the band, often times S8 or S9 in level... We
> should be
> >doing
> >better than this...
Any thoughts on another "white noise" phenomenon?:
>From 2303.800.0 MHz (or 2.303800 GHz) to 2308.200 MHz I have white noise
S5-S7. If I just tune up/down 0.1Khz
out of this band it disappears. Like good white noise should, it goes to 0
on the S meter when I put in my 500 cycle IF level CW filter. It is not
very directional (varies from S5 to S8) as I rotate my 3 foot dish with
horizontal polarization, sitting at 50-70 feet depending on where I have it
cranked. I hear beacon 50 miles away in Philadelphia through it. I first
thought it might be an oscillation in the mast mounted SSB preamp, but the
fact that it stops and starts abruptly at precise, "even" frequencies as I
tune the band makes me think someone is using some sort of spread spectrum
device. Its not microwave oven related (at least not in this house). I
live in a fairly sparsely populated suburb (I have a bit over an acre of
grounds, the houses adjacent have 6 acres on one side and probably 1 on the
other, am at least a half mile away from any commercial buildings, nowhere
near (more than 1.5 miles) industrial area, and a bit over 3 miles from the
local small commercial airport.
And Carl is right, I never considered it might be "man made" till I read his
post vis a vis the raising of the noise floor at contest time.
P.S. the rig is SSB preamp on the mast, SSB 2304 to 144 transverter, ICOM
970H 144 MHz receiver. When I turn off the mast mounted preamp this and all
other sigs disappear due to my coax (1/2 inch andrews heliax to LMR600UF)
run being 200 feet long. The system "works", as I have worked into the
Philadelphia area and also New Jersey on 2304. I can't recall a time when
the noise hasn't been there; I get around it by putting in the narrow CW IF
filters.
Thanks for your comments...
>73 from
Roger Rehr W3SZ ex-AA3QK ex-WA3JYM
mailto:rrehr@epix.net FN20ah
http://www.epix.net/~rrehr
2 Merrymount Road, Reading, PA 19609
610.670.8687
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|