Jerry Stuckle wrote in news:lrgjen$ao4$1@dont-
email.me:

I know EXACTLY what a picowatt is. And I also know what portable
receivers are capable of. Sure, if you feed a picowatt directly into
the front end of a receiver, a good receiver will hear the signal. But
what field strength do you need at the antenna for a portable FM
receiver to hear that signal? And most of your inexpensive portable
receivers will not hear much of a signal (if at all), even if you do
feed a picowatt directly into the front end (not that you can without
major surgery on the receiver).


Which begs the question of whether that front end is a high resistance input
or not. I don't know if it's 50R, 75R, or whatever, but I do know that if
it's a high resistance then talk of power means nothing, it needs spelling
out in volts.

I think one reason this thread got so long is that context is everything, and
people (including me) didn't say enough about it from the off. Cranking the
numbers means little in a case where a smarter question might well be 'how
long is a pice of string?'.

What is helping me a lot here is the direct accounting of people's experience
with various powers, in specific buildings and such, using specific
antennas.. Thanks for those, they give me the quickest grasp of the scale I
need to work with.