Harry wrote:
Hi Cecil,

From "Antenna Theory" by Balanis:

Rr = 2*Prad/|Io^2| = 73 ohms (4-93)

I got Balanis' book and found the above formula.
Thanks a lot! (Tom also mentioned the same book.)

4-94 (I have the 1982 edition) is from formula 4-70.
The math is OK to me. I happen to have a PH.D. degree in math.

For your "passing-out" test, calculate the radiation pattern of a
two-radial groundplane antenna directly from Maxwell's equations
(including the two small cross-polarized lobes that nobody else
mentions), using pencil and paper only, in a pub.

I've seen it done by a math professor from W6. (Nah... it must have been
a party trick... he must have rehearsed that a million times... mustn't
he?)

When he'd finished, Charlie sat back, smiled asked for comments. The
rest of us passed out.


--
73 from Ian G/GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek