[RFI] high noise level...

[Tom Rauch]

Paul,

I ALWAYS use a balun with any balanced directional antenna, because even
small amounts of common mode can cause loss of directivity by filling in
nulls. It just is a very good habit to get into, better safe than sorry.

Also ground the cable (if you easily can) at the mast top and bottom for
lightning protection and reduced common mode problems. Otherwise tape it to
the mast very well, and bring it all the way to the grounded base.

Understand this is all an educated guess, and real results can be
exceptions, but:
If the noise isn't terribly directive when you rotate the quad (assuming the
quad is working OK and has good directivity), and doesn't change when you
crank it up and down, then that is a strong indicator the noise is following
the feedline or mast up to the area of the antenna. Either that or the noise
is close to the antenna and in an area where distance doesn't change much
when the antenna is raised and lowered.

Did you try opening the breakers in your house one at a time, and seeing if
something in your house is causing the noise?? That's always the first thing
I do. Switching power supplies, lights, bad doorbell transformers, and
dozens of other things can cause noise. Telephone lines can conduct noise,
as can power lines. Arcs in power line also cause noise, and it can be
conducted for long distances.

73 Tom