On Tue, 21 Sep 2004 09:51:59 +0200, Toni
wrote:
Yes, but my main objective for all this is feeding the receiver
with the signal comming from the antenna well above the roof, and
(try to) avoid feeding the noise picked by the feedline on it's
way down. Light dimmers, fluorescent tubes, the computer, TV,
etc. I can notice a noise difference when turning them on/off,
and that's what I want to solve/improve.

Hi Toni,

Often, this problem arrives through the AC connection of your radio,
and not over-the-air. You can test this by removing the power cord,
and running off of batteries.

If your set runs off of AC only (no battery option), try borrowing a
portable radio that covers the same bands and use the same
antenna/ground.

If this last step reduces the noise (with the noise sources ON); or
you cannot obtain a portable radio, then try one more option. Use an
extension cord (so that you don't have to move the radio, or
disconnect and move antenna leads) and plug your radio into a wall
outlet in another room. Move this plug around to see if it impacts
the noise problem.

If you find noise is variable by this technique, you are sharing a
circuit with noisy sources and the noise is coming in through the AC
supply. How you solve this is a function of what choices are
available to you. It may mean moving your listening position, or
buying/building an AC line filter (which should not be
expensive/difficult for a low wattage item). This also presumes that
the AC distribution system has a good ground (not always available).
If this is not available, you may need to do it your self, but this
needs to be investigated with care.

73's
Richard Clark, KB7QHC