raypsi wrote:
Hey OM

If I look at the node of a source of 20mW and connect 10 wires to that
node with equal loads, I will have 2mW going down each wire. No matter
how I try and add them up I can't get more than 20 mW.

Now I take a 20 mW isotropic emitter, now your'e saying I feed a dish
with that 20mW emitter through a feed horn and now all of a sudden I
have gain, I have more than 20 mW? Because the dish and feed horn are
able to add the particles and waves, where as with 10 wires I cannot
add the waves and particles?

The only difference in both these are the shape of the dish and the
medium used to convey the wave, particles.
And you can add the waves particles until you run out of dish.


73 OM
de n8zu


Actually your example tends to prove the point that you're questioning.
10 points of 2mw DO add up to 20 mw.

The difference with an isotropic radiator is that there are an infinite
number of points each at say 20mw. Add 'em up by focusing those points
into a single path.

If you can rationalize a 20mw transmitter feeding one direction down a
feedline or waveguide and still getting 20mw EIRP in ALL directions with
an isotropic radiator then it should make sense.

-Bill