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Old October 11th 07, 08:49 PM posted to rec.radio.amateur.antenna
Steve Steve is offline
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First recorded activity by RadioBanter: Jul 2006
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Default Low Noise Receiving antennas

On Oct 11, 3:39 pm, Tony Giacometti wrote:
Steve wrote:
On Oct 11, 2:37 pm, Tony Giacometti wrote:
Steve wrote:
On Oct 11, 1:38 pm, Tony Giacometti wrote:
I live in a neighborhood that as the years have gone on
has added a number of new homes. This has increased the
electrical "noise" for me where S1 or S2 on 80 meters 6-8 yrs ago
is now S7 to S9. At this point in time I don't have the room for a
K9AY setup. I can only "dream" of a beverage.


I have a Timewave ANC-4 which works very well on 40 meters as I can
null out ALL the "noise".


Not so on 80 meters as it only knocks it down 2 S Units.
At best I have an S-6 noise level.


This leads me to believe that I need a separate sensing antenna for 80
meters. Anyone have any ideas for this problem? Is this thinking
correct?


I have been looking at low noise receiving loops and other low noise
antennas. Wellbrook athttp://www.wellbrook.uk.com/seemstohave some
interresting possibilities, but some of the reviews I have read have
made me hesistant to purchase any of their products.


What I need is some serious input from anyone who has any experience
and knowledge in dealing with low band noise issues.
As I am now space limited due to all the new neighbors any solution
would need to take this into consideration.


TIA


What kind of sense antenna are you currently using? I use an active
whip as a sense antenna (specifically, an H-800 "Skymatch" antenna)
and it enables me to squash *any* noise on 80 meters using my ANC-4.


I use a small dipole like antenna where one half is at 45 degrees the
feed point is a few inches above ground and the other side runs paralle
to ground about 1-2 inches above ground. I think the whole sense antenna
is about 6 ft long and runs in a straight line.


I will look up the H-800 on the web.


Did you try various antennas and configurations before you settled on the
H-800? What made you decide to go with the H-800?


I tried different "antennas" and configurations, for this location this
has worked out the best that I have found. I do realize there could be a
zazillion different antennas and configurations.- Hide quoted text -


- Show quoted text -


I tried lots and lots of different sense antennas and got varying
results. The H-800 gives me the best results from among all the sense
antennas I've tried, though of course this could be a function of the
particular kinds of noise present at my QTH.


I will say this. Because I live in an urban area it's been my aim to
defeat RFI in every way possible. I use one of the Wellbrook loops and
that helps, but nothing has been as big a help as the ANC-4 WHEN
MATCHED with the right sense antenna.


Part of me suspects that the ideal setup, at least for me, would
involve having a couple of different active whips to switch back and
forth between. I think the H-800 does well on 80 meters because it's
quite sensitive there. However, it's quite a bit less sensitive on,
say, 20 meters and I'll bet I'd get better results using a different
active whip, or perhaps a wire, on higher frequencies.


I have never considered an active antenna for the sense antenna.
Maybe that would work here.
I wonder if anyone else is doing the same thing or if you have "found"
something really unique.- Hide quoted text -

- Show quoted text -


I know at least one other person who does it. He uses one of the McKay-
Dymek whips. I tried the H-800 simply because I already had it laying
around. I couldn't quite see buying an H-800 just for use as a sense
antenna, as they're fairly expensive, but I've seen them go on ebay
for not too much.

Active whips can be real noise magnets. A huge disadvantage if you're
using one as your receive antenna, but a big plus if noise is what you
want it to hear!