03 Apr 98 06:26, Ivy Iverson said this about 49Mhz to 6m... to Brendan 
Keyport.
 II> Actually, there are technical reasons.  At 144-148 MHz, it is fairly
 II> easy to build tuned circuits which will prevent the transmitter's
 II> signal from getting into the receiver and causing it to lose
 II> sensitivity.  This is called "Desensing."  These tuned circuits are
 II> called "Cavities." They are not coil-and-capacitor tuned circuits,
 II> they are hollow cylanders, usually silver plated on the inside so
 II> that they have a minimum loss.
And those hollow cylinders (sp) actually are the equivalant to a 
coil-capacitor tuned circuit.  The can or cavity is equivalant to the coil 
and the feed point acts as a capacitor. Each one in a 'good' cavity set is 
tunable for band-pass and band-reject.  One without the other makes for 
either a bandpass filter or a bandreject filter.
... (c)1995 * International Association of Tagline Thieves!
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