Topband: S meter reality check

Jim Jarvis jimjarvis at comcast.net
Sat Jan 8 13:36:07 EST 2005


Until we insist on meters being calibrated in dBm,
rather than S units, this discussion is meaningless.

dBm can be calibrated in a receiver.  

If in doubt...what's an S unit?  In whose receiver?
Under what conditions?  

Reality is... Hallicrafters or Hammarlund drove a 
meter off the AGC line in the 30's, and put an 'S' scale 
on it, and we've been waffling around ever since.  

dBm still leaves antenna/site/propagation differences,
but it makes comparison of received signals or antennas 
much more meaningful.  

N2EA
jimjarvis at ieee.org 



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