"Wern" wrote in
news:38fdceedabfe8e06be83e928337c76a8
@localhost.talkaboutelectronicequipm
ent.com:

Thanks for reading this message.
Setup: Catamaran 45'
ICOM M802 with AT140 tuner, professionally installed, sidestay
ant
portside
Battery Charger/Inverter Mastervolt Dakar Sinus Combi, located
in
engine room s/board side.

My problem, if the Battery charger/Inverter is on, which it
normaly is
a carrier every 20khz (+ -) with a 60hz humm is audible over
the whole
HF spectrum. Quite strong so that weak stations are not
readable. The
noise is picked up via the arial not thru the DC supply. If I
disconnect the ant the noise is gone. But just having the ant
tuner
connected with no ant, the noise is audible.
I am looking fwd to some ideas how to get rid of the
interference
thanks and rgds
Wern



Welcome to the club! EVERY boat I work on has RF noise coming
from:
A) the fancy electronic battery chargers
B) the fancy electronic reefers
C) the damned UNBALANCED, unshielded NMEA cables because the lazy
manufacturers tie (-) to ground, not keep it balanced.
D) electronic lighting (flourescents, some fancy LEDs with
dimmers, AC dimmers at the dock)
E) computers running aboard and the stuff that supports them,
including the computer's electronic power supply.
They all generate wide spectrum noise across HF.

At the dock, that awful noise is the crap electrical system, all
corroded up, feeding the dock. Some docks you can't use HF at
all!

The noise is so bad you just have to shut them down to use SSB.
You'll never shield it enough to stop it.

The cure for your battery charger problem is to go back to the
old non-electronic battery charger that produces no noise, except
for its big transformer humming against the steel cabinet. But,
the convenience of an automatic charger far outweighs the RF
noise. You can shut it down and talk on the radio on batteries.

Larry
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