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Old January 21st 09, 03:59 PM posted to rec.radio.amateur.antenna
christofire christofire is offline
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First recorded activity by RadioBanter: Oct 2008
Posts: 173
Default improve S/N for AM car radio by a factor of 2...5...10?


"-.-. --.-" wrote in message
...

"Michael" ha scritto nel messaggio
. ..
is no tuning capacitor in the back of your radio, I suspect this fix will
not work at all.


Nobody prevent you to add it externally, i think.

BTW... curious to know if any ferrite antenna or 2x ferrite antennas in a
sort of cross-coupled way mounted in a waterproof container perform better
than whips. I goggled, but can't find a gain table for ferrite antennas
vs. dipole, or a medium dBI gain (negative, i suppose) for ferrite
antennas mounted into the commons consumer radios.

Chris, -.-. --.-



Amongst several other factors, it depends how you combine the signals from
two crossed ferrite rods/coils - simple in-phase addition of their signals
won't yield a radiation pattern that is omni-directional in the horizontal
plane.

Magnetic antennas are sometimes considered beneficial for mobile reception
of medium/lomg-wave signals because they can be made insensitive to electric
fields, and evidence can be found of greater fluctuation of the electric
field of the wanted signal vs. the magnetic component. Also, some forms of
interference are found to present stronger electric fields than magnetic
ones. However, obtaining the requisite omni pattern isn't trivial.

Chris