[TowerTalk] Antenna Interactions - Reradiated Noise?
David Gilbert
xdavid at cis-broadband.com
Fri Jan 19 17:59:42 EST 2007
The receiving antennas typically used on 160m and 80m are not very
efficient (they make poor transmitting antennas), but they have good
directivity and therefore discriminate against noise coming from
unwanted directions. If the transmitting antenna is resonant and
happens to be positioned near the front (its desired direction) of the
receiving antenna being used at the time, it captures noise from all
directions and re-radiates it to the receiving antenna, thereby
defeating its directivity.
73,
Dave AB7E
kd4e wrote:
> I read this on another list ...
>
> "It does reradiate enough noise, if not detuned,
> to mask weak signals on my receiving antennas ..."
>
> I have read of passive antennas used as passive
> repeaters, so it does make sense that such a thing
> could occur ... but under what sort of circumstances?
>
> Could we in some rare cases actually raise our
> local noise floor, or suffer such, due to new
> antennas or other metallic objects in the area
> of our antennas?
>
> Just curious ...
>
>
--
Anything worth doing is worth doing to excess.
More information about the TowerTalk
mailing list