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Old January 2nd 06, 02:29 PM posted to rec.radio.amateur.antenna,sci.electronics.basics
Dave Oldridge
 
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Default Dipoles and the rig's RF ground...

"billcalley" wrote in news:1136148463.132269.164130
@g49g2000cwa.googlegroups.com:

I realize that dipoles are balanced antennas, but does the rig
itself still need an RF ground too? (I know the radio always needs a DC
ground, of course). How about if the dipole is being used as a
non-loaded "all band" antenna (IE: RIG--TRANSMATCH--LADDER
LINE--DIPOLE) -- would this affect the need for an RF ground on the rig
for operation in the dipole's non-resonant bands? Or is no RF ground
_at all_ required with a dipole; unlike when using random wires or
verticals, and other such un-balanced antennas?


If the antenna is TRULY balanced and the feedline dressed well away from it
at right angles you should have no common-mode currents on the feedline.
That's the ideal case and in that ideal case you need no RF ground at the
radio. The ideal case, however, rarely ever exists in practice.

And end-fed wires can be a whole different ball game. I had to use a 16
foot counterpoise once to "ground" a rig in a 2nd story location when I
end-fed a very long wire with it.



--
Dave Oldridge+
ICQ 1800667