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Old March 27th 08, 05:41 PM posted to rec.radio.amateur.antenna,sci.electronics.design,sci.electronics.basics
AndyS AndyS is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 119
Default Do receiver antennas need matching or not?



Joel Koltner wrote:
This implies only that the antenna/receiver *matching* is good enough... yes?

*** No, it says nothing about the matching. It only says that the
signals
coming down the antenna from the cosmos are greater than the receiver
noise. If the antenna is matched to the receiver, whatever is picked
up
will be more efficiently fed into the receiver, resulting in a still
higher level.
If the antenna is not matched, well, there may be a heck of a lot of
both noise and signal, and even unmatched the results are strong
enough to override the rx noise..... One caveat , tho, ... in some
conditionsm,
a matched receiver input results in a higher receiver noise level....
not much,
but enough for purists to argue the point incessantly :))))) .


(I'm thinking that you would still sometimes prefer a highly directional
antenna over just a dipole even though both increase the background noise.
I.e., in both cases the antenna matching is good enough, but without the
directionality the antenna itself might not be good enough to eliminate
interference, overloading, etc. from sources other than the one you're
interested in.)


**** Of course, and a good point..... I was only talking about desired
signal
and atmospheric noise.... If there is a coherent interferer, then
that's a
whole 'nuther thang...... :)))

Andy W4OAH