chuck wrote:
Hi Jim,

Can you elaborate further on your understanding of just how an
ungrounded antenna wire that receives an increment of charge causes a
response in the receiver as the charge is being acquired?

Hi Chuck - given a large enough increment of charge it's pretty
straightforward. Best example I can think of is a capacitor. Take a
high gain amplifier with an input coupling capacitor and start daubing
clumps of charge onto the unconnected input lead. When the amount of
charge is big enough, you'll hear the pop that results from the
instantaneous change in charge. Thousands of those per second and
pretty soon we're talking some real noise. ;-)

If dust particles are charged as raindrops are (mixed polarity and
magnitude) a typical incremental charge is on the order of 8
picocoulomb. Do we have an understanding of how much power would be
transmitted to the 50 ohm input impedance of the receiver by such an
incremental charge and the mechanism by which that transmission takes
place? Based on anecdotal info, it is not unusual for these impulses to
appear at an average level of several S-units.

Thanks for any insights you can share.

Chuck, NT3G

I've never worked these numbers before, but given your typical charge
per particle of 8 picocoulombs, and a 16uV signal from a 50 ohm
antenna (converted to uamps), I get about 4x10^4 of those particles
per second. Given the density of air, that's a pretty low number I
think. If I'm wrong, please don't blast me. The back of my envelope
here is pretty messy and hard to read. :-)

73, Jim, AC6XG