Topband: 160m noise

[Tom Rauch]

> > Oh, comment on this if you could. The placement of the
loops, because of a
> > pool and other things in the backyard, had to be over
where two of my 160m
> > Inverted L radials (on the gnd, not buried) travel.
Could this be another
> > problem?
> > I only have 16 radials on the L right now. Coupling
problem? The horizontal
> > portion of the L is, about, 60' from the closest loop.
> >
>
> I have found my elevated radials to be a major noise
source for  nearly the
> entire 1/4 wave length...   I had to place my NE Pennant
on the other side of
> the radial with its null to the counterpoise to mitigate
it

This is another reason to use a good ground system!

If your feedline doesn't radiate, any charge flowing into
the antenna terminal has to be exactly balanced by a charge
movement in the ground terminal. This works on transmitting
and receiving. If you have one radial and one ampere net
current flowing up into the antenna and no feedline
radiation, you have one ampere into the radial. With 16
equal radials you'd have 1/16th the current into each radial
at the feedpoint.

Any common mode noise coming from power lines to the chassis
of your radio down the shield to the vertical would excite
the radials and the vertical.

Any noise (or signal) picked up by the vertical would excite
the radials.

The more radials you have, the less junk each radial
radiates.

73 Tom