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Old July 4th 07, 02:56 PM posted to rec.radio.amateur.antenna,alt.tv.tech.hdtv
Ralph Mowery Ralph Mowery is offline
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First recorded activity by RadioBanter: Jul 2006
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Default Front-to-back ratio for UHF antenna


"Bishoop" wrote in message
...
snip

10 or 12 db of forward gain means your recieved signal is about 10 to 16
times as strong as a dipole hanging in the air. If you interpret the
negative number as the amount the signal is down from the forward gain,
the numbers given (9 to 17db) would indicate reception off the back side
would be somewhere near a dipole in open space (1 db net) to -5db (about
1/3 of the signal of a dipole) pickup from the back. I have used
aluminum sheet (tested prior with aluminum foil) tied to the mesh to
completely block reception from the back (a near infinite front to back
ratio) in an extreme case where I had significant multipath reflections
coming in from the back. It really cleaned things up. In your case you
may not need to go to this rather severe step.


snip

Good luck!
--Rick AH7H


10 or 12db of forward gain goes NOT equal 10 "times" the received signal
strength.


Then what do you think it is equal to ?