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Old November 27th 05, 10:12 PM posted to rec.radio.amateur.antenna
 
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Default Station ground/2nd floor


Cecil Moore wrote:
Yep, everyone should realize that a ground wire is N*1/4 wavelength
at certain frequencies, and at those frequencies, is an RF transformer
that locates the standing-wave voltage maximum points at the transmitter. (ouch!)
That's what artificial grounds do - change that *electrical* length
to N*1/2 wavelength. For anyone insisting on an RF ground for an upper
floor, an artificial ground is probably the way to go. I, myself, prefer
balanced antennas and feedlines.
--
73, Cecil http://www.qsl.net/w5dxp


Cecil, Don't you mean that when a ground wire is N*1/4 wavelength at
a particular frequency it locates the voltage mininum (current maximum)
at the transmitter, and the voltage maximum well away from the
transmitter. Artifical grounds use a series LC circuit to try and tune
your ground wire to look like 1/4 wave. If they change the
*electrical* length to 1/2 wave then you would have a voltage maximum
at the transmitter (ouch!).
Gary N4AST