On Thu, 09 Jun 2005 11:38:22 -0500, Cecil Moore
wrote:

Buck wrote:
I am a little confused, so bare with me.....

I put up an antenna with 50 ohm of impedance. I feed it with any
length of 300 ohm feed less than 1/2 L. Then I run 1/2 L of 50 ohm
feed to the radio and I have the 50 ohm match?

Nope, 50 ohms is only one of an infinite number of impedances
you might encounter. For 50 ohms, you feed it with 1/2WL of
300 ohm feedline. This is similar to (but not exactly like)
a G5RV used on 20m.

I put up a 300 ohm antenna. I feed it with 300 ohm twin lead for less
than 1/2 L and 1/2 L of 50 ohm feedline. Is this a 50 ohm match?

Nope, you cannot transform the impedance of a 300 ohm antenna
using 300 ohm feedline. You need reflections to cause an
impedance transformation. A 300 ohm antenna impedance is
not within the green doughnut area below.

The range of impedances that can be matched with a length of
450 ohm ladder-line are represented by the green doughnut at:

http://www.qsl.net/w5dxp/smith.htm

The impedances outside the green area cannot be matched by
only one 450 ohm matching section. The area in the doughnut
hole cannot be matched by only one 450 ohm matching section.


When I click on your links, I get connection refused from qsl.net

--
73 for now
Buck
N4PGW