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Old August 25th 08, 01:27 AM posted to rec.radio.shortwave
Brian Hill[_2_] Brian Hill[_2_] is offline
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First recorded activity by RadioBanter: Oct 2007
Posts: 62
Default AM-loop versus whip antennas


"Brenda Ann" wrote in message
...

"KaitoWRX911" wrote in message
...
Why does FM and SW use whip antennas, while AM uses directional
internal ferrite-bar antennas? Couldn't the internal antenna be used
for SW and FM, or vise-versa? Thanks... excuse my ignorance...



Loop antennas are more efficient at lower frequencies, along with being
more directional, and less prone to noise pickup.

Many cheap shortwave radios used internal ferrite antennas (separate coils
on the same bar as the AM/MW antenna) for the main antenna tuned circuits
on the SW bands. This did allow some reception without using the whip.

For VHF/FM, the whip is more efficient because it can approach a 1/4
wavelength of the received signal.



The number #1 thing in radio is your ariel. Experiment with ant's!!!! Every
seasoned radio person will take a good ant with any reasonable RX over a
great RX with a mediocre ant. If your ariel isn't up to par, then it doesn't
matter how good your RX is.
--
Regards
B.H.
Hill Amplification
http://hillamplification.com

Brian's Radio Universe
http://webpages.charter.net/brianhill/500.htm