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🖥️ActiveHome Pro => ActiveHome Pro General => Topic started by: paul on June 09, 2005, 10:05:22 AM

Title: Line Interference Question
Post by: paul on June 09, 2005, 10:05:22 AM
I have been having trouble with noise in my
powerlines.  I was wondering if anyone new if
instead of installing noise fitlers on every
elcetronic device that is causeing noise in
the line if amplifiying the signal would work
instead.  They have amplifiers on smarthome
and if the signal is amplified is there a
need for noise filter?
Title: Re: Line Interference Question
Post by: donald mcmow on June 09, 2005, 10:16:21 AM
The one thing is that the amplifier will
also amplify the noise as well. The best
thing to do is find out what device is
causing the noise and deal with it on an
individual basis. The signal you have now
might be more than enough to cover your
whole house as it is. The only time you
should be considering using an amplifier is
if you are having problems covering the
whole house - not due to noise problems.
Title: Re: Line Interference Question
Post by: paul on June 09, 2005, 10:22:20 AM
OK sounds good thanks for the reply
Title: Re: Line Interference Question
Post by: paul on June 09, 2005, 10:25:20 AM
One more question... Do I need mulitple line
filters for each device that is casueing
noise.  Or would one 5amp fitler plugged into
the wall clean the entire line??
Title: Re: Line Interference Question
Post by: donald mcmow on June 09, 2005, 10:33:35 AM
First of all determine what device is
causing the noise. Check the power ratings
on the device - you need a filter that will
handle the devices power requirments - if
it is close to the filter rating then you
need the next higher filter just to be
safe. This will only cover that particular
device unless you have a number of devices
plugged into a powerbar - then if the
filter is plugged into the wall with the
powerbar plugged into it - all will be
covered.
Title: Re: Line Interference Question
Post by: donald mcmow on June 09, 2005, 10:35:20 AM
If your devices are all plugged into a
powerbar then ADD UP ALL of the power
amperage required and then get the
appropriate filter.
Title: Re: Line Interference Question
Post by: roger1818 on June 09, 2005, 10:51:03 AM
Paul:  Donald is right.  One other thing is
if the signal is strong a signal amplifier
can actually make the signal weaker (the
original and amplified signals can cancel
each other out).  Besides, it doesn’t
matter how strong your signal is if the
module interprets the noise as a signal.
Modules with AGC are better at picking out
a strong signal in a noisy environment or a
weak signal in a quiet environment.

Having said that, if the devices in
question are absorbing signal and not
generating noise (it is difficult to
differentiate these two without a signal
monitor), a signal amplifier might help.

One alternative is to put a 20A filters on
circuits that have several noisy devices.
This will prevent X10 devices from working
on those circuits though so be careful
where you install them.

Another alternative is to use a shunt
filter (such as the ACT AF310).  A shunt
filter will filter out noise that is above
or below 120kHz without affecting your X10
signal.  Obviously, if the noise is at or
near 120kHz, a shunt filter won’t help, but
it can help with some types of noise.
Title: Re: Line Interference Question
Post by: paul on June 09, 2005, 10:56:30 AM
Thanks alot you have been a big help.
Title: Re: Line Interference Question
Post by: joe s. on June 09, 2005, 11:55:01 AM
Generally there are only a couple devices
in a typical home that generate noise/or
soak up X10 signals.  Although its tedious
to go around unplugging things 'til the X10
commands work reliably, and then filtering
the offenders - it is usually the most
effective way. I assume you have a phase
coupler of some sort?

If you don't, then it will appear like half
of your outlets work - and the other half
don't....but that's not caused by noise,
it's caused by poor signal propagation
between phases.