I've got a problem with electrical interference through the tv's and
computer speakers.
It's really noticeable when the washing machine is running or fridge
compressor clicks in, and when somebody is operating a drill/power saw
close by.
I got one of those surge protected power boards but they don't help.
There's a line filter that's supposed to do the whole house, has anyone
fitted one of these things? Do they work? What other options do i have?

On Sun, 06 Feb 2005 18:44:59 +1100, bigtom wrote:

I've got a problem with electrical interference through the tv's and
computer speakers.
It's really noticeable when the washing machine is running or fridge
compressor clicks in, and when somebody is operating a drill/power saw
close by.
I got one of those surge protected power boards but they don't help.
There's a line filter that's supposed to do the whole house, has anyone
fitted one of these things? Do they work? What other options do i have?

bigtom wrote:
I've got a problem with electrical interference through the tv's and
computer speakers.
It's really noticeable when the washing machine is running or fridge
compressor clicks in, and when somebody is operating a drill/power
saw
close by.
I got one of those surge protected power boards but they don't help.
There's a line filter that's supposed to do the whole house, has
anyone
fitted one of these things? Do they work? What other options do i
have?

Where are you located - Country and state? Are you in the city,
suburbs, rural, nearest house, nearest garage where drill/power saw is
operated, etc?

What is your power source? It sounds like it must be a fairly high
impedance source, or you have the worst possible luck concerning
inferior electronic equipment.

The first thing to do is determine if the noise is coming into the
electronics via radiated signals, or if it is coming in on the AC power
lines. The best way to determine this is with a portable/battery
operated am/fm radio. When the interference is occurring, take the
radio and place it right next to the AC power line feeding the
appliance that is being interfered with.

Tune the radio on sam and/or fm until you can hear the same noise in
the radio that you see/hear on whatever is being interfered with (EUT).
Then, without changing the orientation of the radio, move it away from
the power line. If the noise decreases, then noise is most likely
being introduced into the EUT via the AC power line. A filter on the
input of the EUT should have a positive effect. On the other hand, if
the noise from the radio continues as it is moved away from the power
line, then you have a radiated noise problem. Only a stronger signal
will help.

Please provide more info, I have many years solving interference
problems and served as president of the IEEE Electromagnetic
Compatibility Society so we may be able to figure out what is
happening.

H. R.(Bob) Hofmann

im in Melbourne, Australia out in the suburbs. its a small home next
on its own block of land.
the drill/saw noises are only occasional.
its the other appliances in my home that cause the main problems.
I tried the am radio method next to the washing machine/light switches
and the further i move the radio away, the less noise it makes.
It sounds like the noise is being introduced through the wiring.


Where are you located - Country and state? Are you in the city,
suburbs, rural, nearest house, nearest garage where drill/power saw is
operated, etc?

What is your power source? It sounds like it must be a fairly high
impedance source, or you have the worst possible luck concerning
inferior electronic equipment.

The first thing to do is determine if the noise is coming into the
electronics via radiated signals, or if it is coming in on the AC power
lines. The best way to determine this is with a portable/battery
operated am/fm radio. When the interference is occurring, take the
radio and place it right next to the AC power line feeding the
appliance that is being interfered with.

Tune the radio on sam and/or fm until you can hear the same noise in
the radio that you see/hear on whatever is being interfered with (EUT).
Then, without changing the orientation of the radio, move it away from
the power line. If the noise decreases, then noise is most likely
being introduced into the EUT via the AC power line. A filter on the
input of the EUT should have a positive effect. On the other hand, if
the noise from the radio continues as it is moved away from the power
line, then you have a radiated noise problem. Only a stronger signal
will help.

Please provide more info, I have many years solving interference
problems and served as president of the IEEE Electromagnetic
Compatibility Society so we may be able to figure out what is
happening.

H. R.(Bob) Hofmann

"bigtom" wrote in message
...
im in Melbourne, Australia out in the suburbs. its a small home next
on its own block of land.
the drill/saw noises are only occasional.
its the other appliances in my home that cause the main problems.
I tried the am radio method next to the washing machine/light switches
and the further i move the radio away, the less noise it makes.
It sounds like the noise is being introduced through the wiring.

You need a bigger aerial mate. Either a big vertical whip or a long one
between a tree and the house. But putting filters on the radio power cord
and the appliances will help. Dick Smith or Tandy should have them if you've
got a store within cooee. Otherwise try the local blokes.
--
N

Since it looks like the noise is coming in mostly on the pwer lines,
you will need a filter on the AC power to each receiver that is
experiencing the problems. Does it happen on all radios, all
frequencies? No problems for your neighbors?

You talk about noise on the computer speakers. What are you listening
to on your computer?

You might also try getting in touch with a local amatuer radio (ham)
operator and ask him/her for help. Most hams are happy to lend their
expertise in solving these types of problems, and especially if someone
isn't blaming them for their reception problems.

If this doesn't work, e-mail me directly and I'll try to work with you.

H. R.(Bob) Hofmann

wrote in message
oups.com...
Since it looks like the noise is coming in mostly on the pwer lines,
you will need a filter on the AC power to each receiver that is
experiencing the problems. Does it happen on all radios, all
frequencies? No problems for your neighbors?

From the sound of it he's out in the wop-wops. He just needs a big aerial to
get a better signal. Australia is a bloody big country you know.
--
N

Not necessarily true that a weak signal is reason for
problem. Devices he listed, if bought on price, are often
missing filtering that is suppose to be part of the device's
power supply. During exceptionally strong signals, one would
not notice the design defect in a TV. If his signals are weak
and he is suffering noise, then quite likely the appliance
input filter is badly designed, or more often - they forgot to
include it. Furthermore he suffers this problem through the
cheap power supply for his sound card. Radio wave strength is
totally irrelevant to computer sound systems.

OP may need buy and connect a line filter that did not come
with (and should have been provided in) the noise detecting
appliance. But as HRHofmann implies, finding the source is
part of solving the problem - which is why EMC solutions can
be so difficult.

One further note. Sometimes solving the noise at the source
of that noise can improve appliance life expectancy. IOW
there would be two solutions. First is to fix defective
appliances that are detecting the noise. Second would be to
improve a noise generating device by eliminating the source of
that noise (ie a snubber across switch contacts might also
prolong switch life expectancy).

The OP may discover he is about to confront an interesting
and complex problem. Furthermore, the OP is encourage to
first ask technical questions before wildly buying solutions.
Those protection power boards don't even claim to address his
type of problem. But manufacturer conveniently forgets to
include essential facts so the OP will enrich that
manufacturer; buy a totally ineffective solution. Those power
boards provided him nothing useful nor even claim to address
his problem.

OP is encouraged to locate a source of AC line filters since
he may need one to perform experiments. An AC line filter can
be part of an inexpensive experiment - whereas that power
board was an expensive wild speculation.

NSM wrote:
wrote in message
oups.com...
Since it looks like the noise is coming in mostly on the pwer lines,
you will need a filter on the AC power to each receiver that is
experiencing the problems. Does it happen on all radios, all
frequencies? No problems for your neighbors?

From the sound of it he's out in the wop-wops. He just needs a big
aerial to get a better signal. Australia is a bloody big country
you know.
--
N

"w_tom" wrote in message
...
Not necessarily true that a weak signal is reason for
problem. ...

Do you live in Australia?
--
N