[TowerTalk] Reference plane for FCC power limit

[Bill Turner]

On Wed, 3 Sep 2003 15:12:32 -0400, Chuck Counselman
<ccc at space.mit.edu> wrote:

>The value of Zo does _not_ completely 
>determine the ratio of E/I, whether you  take E and I in this formula 
>to be real or complex.


I think you're using the word "real" where I would use "RMS" and
"complex" where I would use "reactive", but aside from that, ok.

>You can easily see that Zo does not determine 
>the ratio of E/I by considering a lossless line terminated in a 
>short-circuit.  At this termination and every integer half-wavelength 
>back from it, the ratio of E/I equals zero, completely independent of 
>the value of Zo.  The ratio of E/I equals Zo only when there is no 
>reflected wave.

Correct, in that specific hypothetical example, which the FCC couldn't
care less about.  I was referring to the RMS E and I at the output of
the transmitter, which is what the FCC will be interested in.  I'm
sure if you try to slip your hypothetical stuff by them, they will
slap on a 50 ohm load, retune to whatever your anode E and I meters
said beforehand, and quickly fill out your citation.  When you go to
court, I'm sure the judge won't care any more than the FCC did.

-- 
Bill, W7TI