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Old October 30th 04, 10:55 AM
Volker Tonn
 
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Al Klein schrieb:
On Fri, 29 Oct 2004 22:45:21 +1000, "Troy R."
said in alt.radio.scanner:


I am after a good V/UHF airband antenna and found this on a Google search.
Anybody actually own one and can tell me how they perform?



http://www.nevadaradio.co.uk/acatalo...airmaster.html



They don't seem to know much about it. Discones aren't resonant
antennas, but they do pick up signals from the design frequency to
daylight..


Not having read the linked page....
Discones ARE resonant on an extremly wide range.
Therefore they have nearly no gain above the (theortical) isotropic
antenna. This means they have a loss of around 1/2 S-unit against a
dipole or a half-wave vertikal antenna on a specified frequency. Not too
bad for a compromise.
The resonant range of a well designed and built discone is spread 1:10
on wich you can transmit. This is 50 to 500 Mhz or 100 to 1000Mhz for
example, covering the most wanted frequencies for scannists and is also
usable on ham-bands or FRS to transmit.
The receiving range -allowing an impedance mismatch- is much wider when
(usually) allowing a loss of 1 S-unit (-6dB). The difference you only
will notice on faint signals.
There are some other antennas too -directional and omnidirectional-,
providing a relatively wide resonant range but not nearly as wide as a
discone.