TopBand: RX noise figure and gain

[Robert g. Flory]

Dear Topbanders,

I have never found it necessary to use a preamp on a Beverage, from the
standpoint of noise figure.  I have always heard the noise level go up when
attaching the Beverage to the receiver.  Many times, though,  the signals
still sound weak, masked by hiss from the audio stage of the receiver.  I
think that the perceived benefit of using a preamp comes from increased
system gain, not from enhanced noise figure. 

The situations in which I have found a preamp useful have usually involved
splitting a Beverage to feed multiple receivers, or with certain receivers
like the TR7 and R4c which seem to lack overall system gain.
 
Rob K2WI

--
FAQ on WWW:               http://www.contesting.com/topband.html
Submissions:              topband@contesting.com
Administrative requests:  topband-REQUEST@contesting.com
Problems:                 owner-topband@contesting.com