Re: How many joules --> e.m. waves?

[Bob Sciamanda <Sciamanda@worldnet.att.net>]

LUDWIK KOWALSKI wrote:
> . . . 
> I just realized that there are two kinds of resonance in this problem,
> one for the oscillations of charge between C and L and one for the antenna
> itself. The first kind depends only on L*C; it determines lambda=c/f, where
> c is the speed of light. The second (standing waves) depends on (d/lambda).
> . . .						Ludwig

Along with some other posters, I too was a "Ham" operator (W3NLV)in my
youth.
Let me add that the usual transmitter ended in an LC circuit which was
synchronously 
pulsed into oscillation by a class C tube (later, transistor)
amplifier.  The antenna 
was a "separate" circuit, most often an electric (as opposed to a
magnetic) dipole 
cut to a resonant length (although many, many variations are used).  The
antenna 
was often coupled to the LC "tank" circuit by making the inductance L
the 
primary of an air core transformer and feeding the antenna through a
transmission 
line connected to a secondary winding.  

Here one must consider the resonant properties and the coupling of three
sub-systems: 
the LC tank circuit, the transmission line, and the antenna. 
(The whole thing is of course fed by an oscillator driving the class C
amlifier 
at the LC resonant frequency.)

Ludwig (and Heinrich Hertz) is putting all of this into a one-shot
charged 
capacitor and loop of wire!  We often learn more from the simpler
embodiments 
of physical principles!
                                                           
-- 
Bob Sciamanda		sciamanda@edinboro.edu
Dept of Physics		sciamanda@worldnet.att.net
Edinboro Univ of PA	http://www.edinboro.edu/~sciamanda/home.html
Edinboro, PA		(814)838-7185