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Old July 7th 04, 11:35 PM
Richard Clark
 
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On Wed, 07 Jul 2004 17:44:58 -0400, Albert wrote:

I'd like to put up a 40 to 60 wavelength (per leg) vee beam for 144
Mhz. It would be 12 feet off the ground and unterminated.

....
What type of matching do I need to feed it with a 50 ohm output solid
state power amp?


Hi Art,

Too many details lacking. 40 to 60 covers too much turf (beyond the
pun), you neglect how wide it will be at the ends too. I ran a couple
of tests to see the gain from 17 to 22dBi and the Z anywhere from 200
Ohms to 2000 Ohms. One thing to consider is the "law of diminishing
returns." The gain for a much smaller V is not much different from
the giant one (think 3dB for each doubling - as a shorthand, I am sure
this fails long before the 20, much less 50th, wavelength is reached).

73's
Richard Clark, KB7QHC