Thread: 160 Meter noise
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Old January 20th 04, 04:08 PM
John Passaneau
 
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You might think about what I did for 80m. I made a 1/8 wave spaced cardioid
array out of ham stick mobile whips. I used just enough ground radials to
get a 50 ohm Z to make the phasing lines easier. In my case that was 4 10'
long wires laid on the ground for each antenna. I feed them with 1/4 wave
lines from a relay box that has the 135 deg. phasing line. The relay
switches the feed point between the ends of the phasing line to make the
direction switch. This is not a transmitting antenna, the losses are too
high for that, but it works well as a receive antenna. I get about 20db
front to back, much more in some directions, my noise went from S-7 to S-9
to S-0 but the signals are perfectly copyable even when not even showing on
the S meter. I do not use a preamp, as I don't care if the signal don't show
way up on the meter, all I care about is the signal to noise ratio which
went way up. No more narrow filters, DSP noise reduction and headaches from
the headphones and the roar of the noise. It's made 80m DXing much more
pleasurable. The best part of this method is it doesn't take up much room,
32' on 80m, and is not very visible It's pattern is similar to a beverage
especially in elevation but takes up a lot less room. Disadvanges is that
it works only over a small range of frequencies, in my case the SSB DX
window +/- some on 80m where a beverage or a loop can work on several bands.
I would have like a rosette of beverages but you don't do that on a 0.7acre
lot.


--
John Passaneau, W3JXP
Penn State University



"Metalhead" wrote in message
...
My problem is space. I live on a small 1/4 acre lot and can't get
much distance from a receiving loop and the inverted L (maybe about 30
feer or so at most.) My guess is that this is too close and will
alter my radiation pattern on the transmitting L. How far away should
the loop be from the L for this?


On Tue, 20 Jan 2004 11:52:20 GMT, "Floyd Sense"
wrote:

I'm located quite a way from any city noise sources, and all power lines

in
the area are underground. On my inverted L for 160, my noise level peaks

at
S1 on 160 and that's with the pre-amp on. I'd consider an S8 noise level
intolerable! A K9AY loop might be worth trying, depending upon the

source
of your noise. It has a pretty good steerable null and will help if the
noise is coming from one direction.

73, K8AC

"Metalhead" wrote in message
.. .
I have just recently put up a 160 meter inverted L antenna. I briefly
had up a shortened inverted V which I had up for about 1 year. I know
that 160 is a noisy band, but I am curious what kind of noise levels
others normally get on 160. With the inverted V, I would get about a
S7 noise level. On the inverted L, I get an S8 noise level (with the
noise blanker on.) I understand that the vertical will pick up more
man made noise and I do have my share of power line noise here on my
small city lot. Is this typically normal or is this extremely noisy
for 160? Just curious what kinds of noise levels others get. I am
going eventually put up a small receiving loop for 160 meters in the
future.

Thanks for any input.

Burch
K4QXX