View Single Post
  #11   Report Post  
Old June 13th 07, 09:05 PM posted to rec.radio.shortwave
Ron Hardin Ron Hardin is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 127
Default Bigger RFI threat than BPL, IBOC?

N9NEO wrote:
I remember them telling me in school - GO BADGERS! - that in order to
have a field that was not static there had to be both H and E
components. Is it possible to have a field in the MHz range that only
has one component? either B or E? I don't think so.


The time change of E or B produces a perpendicular B or E, which is
what gives a wave equation. I think Maxwell intuited that as a
``displacement current'' necesssary to account for the circuit
completion in charging a capacitor. Anyway it turns it into a wave
equation, which I think he also noticed.

Think dE/dt=-B and dB/dt=E and notice that cos(t) and sin(t) are a
solution.

The actual equations have a curl to turn it into something involving
space as well.

If it's changing, it propagates.
--
Ron Hardin


On the internet, nobody knows you're a jerk.