Just throwing an arbitrary noise antenna out there is not unlike, when
trout fishing, just walking up to a river, throwing in whatever bait,
lure or fly strikes you, at whatever spot appeals to you, and then
pronouncing the river devoid of fish when an immediate strike is not
experienced.
Finding the right noise antenna may take a great deal of effort, and the
odds are high that, once you find one that "works" for a specific noise
on a specific band, it will be mediocre for any other band or noise. So
you may need an arsenal of noise antennas to battle different noises.
The right one may well reduce the noise dramatically--40 dB is not
unrealistic. I've done that here. My ANC-4 is not on all the time, and
is not helpful all the time, but when it is, it is invaluable.
Just remember---noise cancellation requires summing the
singal-plus-noise with a noise signal which is EXACTLY the same
amplitude and EXACTLY out of phase with the noise component.
dick sander wrote:
>
> I recenctly picked up a JPS ANC-4 Noise Canceller at a flea market.
>
> When I key the rig, the COR kicks in OK.
>
> I installed a wire outside from my tower out of the center of RG213 for
> a sense antenna. The wire is about 8 ft long and runs from the 12 ft
> level towards ground about 45 degrees and is tied off (insulated) to a
> chain link fence.
>
> When I point my beam north I pick up noise (10m). On my FT-1000MP the
> noise blanker cuts it out (2-3 S-units). Using the ANC-4 I find a "dip"
> in the noise of about 1 S-unit. If I turn the gain up high and move from the
> "dip", I hear spurious noises. The signals are also about an S-unit down.
> (The manual says about 6 dB insertion loss.)
>
> On 160m, all I see is the insertion loss with no noise reduction at all!
>
> Does the above description sound as if it's working, or did I get
> a dud? If it's working, I'm certainly not impressed.
>
> Anyone with some experience to guide me?
>
> 73, Dick Sander -K5QY
>
> --
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--
Garry Shapiro, NI6T
Visit the Northern California DX Club home page:
http://www.ncdxc.org
--
FAQ on WWW: http://www.contesting.com/topband.html
Submissions: topband@contesting.com
Administrative requests: topband-REQUEST@contesting.com
Problems: owner-topband@contesting.com
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