View Single Post
  #16   Report Post  
Old March 2nd 06, 07:09 PM posted to rec.radio.shortwave
Mark Zenier
 
Posts: n/a
Default balun spec depending on coax impedance

In article ,
Bob Miller wrote:
Why do you think an antenna for multi-frequency use has an impedance
no higher than 450 ohms? As an example, check the impedances of the
all band doublet at http://www.cebik.com/wire/abd.html


You don't understand. We're not transmitting.

The goal in not some absolute effiency for raditating RF energy or babying
the RF final amplifier, but maximising the signal to noise ratio of the
signal fed into the receiver.

At low cost.

There's great improvment with these transformers because you can
stick some random hunk of hookup wire out in weeds, far enough away
from the computers, light dimmers and other modern electronic crap.

And if your receiver doesn't have high impedance input, you'll get
even more signal off a random wire, with either the transformer remotely
located or at the receiver.

With receivers, it's all relative.

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)