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Power Circuit Noise?

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May 13, 2005 5:05:27 AM

Archived from groups: rec.audio.tech (More info?)

Hi,

I just started to hear power circuit noise on my PC speaker system. If
I turn on my paper shredder, I can hear it on my PC speaker system. Do
I have a ground issue? How can I fix this?

Thanks,
Dan

More about : power circuit noise

Anonymous
May 13, 2005 5:05:28 AM

Archived from groups: rec.audio.tech (More info?)

In <r3Tge.58$bn.34@tornado.rdc-kc.rr.com>, on 05/13/05
at 01:05 AM, Dan <dan@nospam.com> said:

>I just started to hear power circuit noise on my PC speaker system.
>If I turn on my paper shredder, I can hear it on my PC speaker
>system. Do I have a ground issue? How can I fix this?

Dave and Steve's advice is reasonable.

Have you changed anything?

Sometimes the quality of computer speakers and shredder motors are
dreadfully low and such problems are expected.

Are there any other symptoms beyond the computer speakers? If you use
an antenna for your TV, how is the TV picture? Can you see any
interference when the shredder runs?

Tune an AM portable radio between stations at the upper end of the band
and run the shredder. Is the radio upset? If so, move the shredder to
another circuit and listen to the radio again. Same results? If so, the
shredder has a problem. If not, there is something odd about the
original circuit (and we can't give the shredder a clean bill of
health). If you purchased the lowest price possible surge protector
outlet strip, the technology could be taking it's revenge. Cheap (less
than about $20.00) outlet strips don't protect much.

In general, as you walk around listening to your radio, spots where the
noise seems concentrated are "interesting". The spot could be near the
primary source (bad motor, bad connection) of the noise or a weak spot
in the system that should be evaluated.

-----------------------------------------------------------
spam: uce@ftc.gov
wordgame:123(abc):<14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13> (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------
Anonymous
May 13, 2005 5:11:41 AM

Archived from groups: rec.audio.tech (More info?)

>Hi,
>
>I just started to hear power circuit noise on my PC speaker system. If
>I turn on my paper shredder, I can hear it on my PC speaker system. Do
>I have a ground issue? How can I fix this?

It might be an issue with the ground. It might also be a problem with
the hot or neutral connnections on your circuit.

No way to tell for sure at a distance.

I would suggest having a competent licensed technician check out your
wiring. If you've got a loose wire somewhere in the walls (at an
outlet or circuit breaker) or have a circuit breaker going bad, this
could create a very real shock or fire hazard.

If you're seeing odd signs, such as a light getting *brighter* when
your fridge starts up or you turn on another appliance (rather than
getting *dimmer*), or if any of your appliances have started running
slower than usual, I'd suggest calling the electric company. These
can be symptoms of an "open neutral", and the resulting low and high
voltages can damage things in the house. [We had this happen a couple
of months ago, when a squirrel chewed through the neutral wire right
near the power pole.]


--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
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Anonymous
May 13, 2005 7:49:31 AM

Archived from groups: rec.audio.tech (More info?)

On Fri, 13 May 2005 01:11:41 -0000, dplatt@radagast.org (Dave Platt)
wrote:

>If
>>I turn on my paper shredder, I can hear it on my PC speaker system.
Besides what others said.
Doed your shredder use a Brush (universal) type motor? The brushes may
be dirty or worn causing arcing.

IMHO Shredders, power staplers, VACUUM Cleaners do not belong on a
computer circuit and NEVER plugged into the same outlet STRIP.
FWIW the surge circuit is now probably dead or weak if you *have* used
this equipment on a surge-outlet strip.

Old Main Frame Data Center guy :/ 
Steve
, _
, | \ MKA: Steve Urbach
, | )erek No JUNK in my email please
, ____|_/ragonsclaw dragonsclawJUNK@JUNKmindspring.com
, / / / Running United Devices "Cure For Cancer" Project 24/7 Have you helped? http://www.grid.org
May 13, 2005 6:56:23 PM

Archived from groups: rec.audio.tech (More info?)

On 5/12/2005 10:49 PM, Steve Urbach wrote:
> On Fri, 13 May 2005 01:11:41 -0000, dplatt@radagast.org (Dave Platt)
> wrote:
>
>
>>If
>>
>>>I turn on my paper shredder, I can hear it on my PC speaker system.
>
> Besides what others said.
> Doed your shredder use a Brush (universal) type motor? The brushes may
> be dirty or worn causing arcing.
>
> IMHO Shredders, power staplers, VACUUM Cleaners do not belong on a
> computer circuit and NEVER plugged into the same outlet STRIP.
> FWIW the surge circuit is now probably dead or weak if you *have* used
> this equipment on a surge-outlet strip.
>

The shredder is plugged directly in a wall outlet of the other side of
the room from where my PC is hooked up.
Anonymous
May 14, 2005 2:46:26 AM

Archived from groups: rec.audio.tech (More info?)

On Fri, 13 May 2005 14:56:23 -0500, Dan <dan@nospam.com> wrote:

>On 5/12/2005 10:49 PM, Steve Urbach wrote:
>> On Fri, 13 May 2005 01:11:41 -0000, dplatt@radagast.org (Dave Platt)
>> wrote:
>>
>>
>>>If
>>>
>>>>I turn on my paper shredder, I can hear it on my PC speaker system.
>>
>> Besides what others said.
>> Doed your shredder use a Brush (universal) type motor? The brushes may
>> be dirty or worn causing arcing.
>>
>> IMHO Shredders, power staplers, VACUUM Cleaners do not belong on a
>> computer circuit and NEVER plugged into the same outlet STRIP.
>> FWIW the surge circuit is now probably dead or weak if you *have* used
>> this equipment on a surge-outlet strip.
>>
>
>The shredder is plugged directly in a wall outlet of the other side of
>the room from where my PC is hooked up.
That does not stop the Electo-Magnetic Noise generated if it has a
noise spewing motor.
Barry has the right ideas on isolating the problem.
Fix the CAUSE.
If the speakers are the only device affected (not heard on the AM
radio or other devices), then a overly sensitve (poorly shielded)
Speaker is the cause.

Note: Speaker (amplifier) signal leads should not be tightly bundled
with AC power cords.
, _
, | \ MKA: Steve Urbach
, | )erek No JUNK in my email please
, ____|_/ragonsclaw dragonsclawJUNK@JUNKmindspring.com
, / / / Running United Devices "Cure For Cancer" Project 24/7 Have you helped? http://www.grid.org
May 14, 2005 5:33:38 AM

Archived from groups: rec.audio.tech (More info?)

Steve Urbach wrote:
> On Fri, 13 May 2005 14:56:23 -0500, Dan <dan@nospam.com> wrote:
>
>
>>On 5/12/2005 10:49 PM, Steve Urbach wrote:
>>
>>>On Fri, 13 May 2005 01:11:41 -0000, dplatt@radagast.org (Dave Platt)
>>>wrote:
>>>
>>>
>>>
>>>>If
>>>>
>>>>
>>>>>I turn on my paper shredder, I can hear it on my PC speaker system.
>>>
>>>Besides what others said.
>>>Doed your shredder use a Brush (universal) type motor? The brushes may
>>>be dirty or worn causing arcing.
>>>
>>>IMHO Shredders, power staplers, VACUUM Cleaners do not belong on a
>>>computer circuit and NEVER plugged into the same outlet STRIP.
>>>FWIW the surge circuit is now probably dead or weak if you *have* used
>>>this equipment on a surge-outlet strip.
>>>
>>
>>The shredder is plugged directly in a wall outlet of the other side of
>>the room from where my PC is hooked up.
>
> That does not stop the Electo-Magnetic Noise generated if it has a
> noise spewing motor.
> Barry has the right ideas on isolating the problem.
> Fix the CAUSE.
> If the speakers are the only device affected (not heard on the AM
> radio or other devices), then a overly sensitve (poorly shielded)
> Speaker is the cause.
>
> Note: Speaker (amplifier) signal leads should not be tightly bundled
> with AC power cords.

I don't have an AM radio available right now. If I unplug my speaker
system from the PC, then I don't hear the shredder. So the noise is
traveling through my PC sound card, right?

When I get the AM radio. Should I plug it into AC power or run on battery?
Anonymous
May 14, 2005 7:41:49 AM

Archived from groups: rec.audio.tech (More info?)

On Sat, 14 May 2005 01:33:38 GMT, Dan <dan@nospam.com> wrote:

>When I get the AM radio. Should I plug it into AC power or run on battery?
Run it on battery.
Tune BETWEEN stations where the AGC circuit allows maximum RF gain.
Determine where the Ferrite loopstick is located in the radio,
(usually in the top and horizontal).
Hold the radio with your hands as far away from the loopstick as
possible.
The sides of the radio are the pickup direction. rotate/tilt the radio
twoard suspected noise sources and listen. Move about, when you rotate
for peak noise, does the edge point toward the the same item?
Remember, the pickup is off both edges, that is why circling is best
to locate the noise. Remember to tilt up for ovrhead sources like gas
discharge light fixtures, utility pole insulators (or dow if on a
upper storey).
I found bad utility pole insulators that were messing up my TV picture
that way (BTW they will normally make noise in foggy/moist weather).

Where do the speakers get their power?
Plug a set of headphones into the sound card, carefully test levels
before placing over your ears. What do you hear that way?
Plug the speakers into a Walkman type device (on battery, preffered),
What happens?

Tracking noise by remote <G> is difficult.
, _
, | \ MKA: Steve Urbach
, | )erek No JUNK in my email please
, ____|_/ragonsclaw dragonsclawJUNK@JUNKmindspring.com
, / / / Running United Devices "Cure For Cancer" Project 24/7 Have you helped? http://www.grid.org
Anonymous
May 15, 2005 2:11:45 AM

Archived from groups: rec.audio.tech (More info?)

In <qgra81do65mul8nu3sa6ejalg4c9a4s95n@4ax.com>, on 05/14/05
at 03:41 AM, Steve Urbach <dragonsclaw@NOTmindspring.com> said:

>I found bad utility pole insulators that were messing up my TV picture

How long did it take the power utility to own the problem? My father
had that problem. It took me months to convince him to walk the block
with his radio. After he identified the poles, the utility dragged its
heals for another few months until my dad organized a neighborhood
"call-in". Eventually, they brought around their special diagnostic
van, scanned the neighborhood, then replaced most of the insulators on
the block.

-----------------------------------------------------------
spam: uce@ftc.gov
wordgame:123(abc):<14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13> (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------
Anonymous
May 15, 2005 6:55:05 AM

Archived from groups: rec.audio.tech (More info?)

On Sat, 14 May 2005 22:11:45 -0400, zzzz@zzzz.zzz (Barry Mann) wrote:

>In <qgra81do65mul8nu3sa6ejalg4c9a4s95n@4ax.com>, on 05/14/05
> at 03:41 AM, Steve Urbach <dragonsclaw@NOTmindspring.com> said:
>
>>I found bad utility pole insulators that were messing up my TV picture
>
>How long did it take the power utility to own the problem? My father
>had that problem. It took me months to convince him to walk the block
>with his radio. After he identified the poles, the utility dragged its
>heals for another few months until my dad organized a neighborhood
>"call-in". Eventually, they brought around their special diagnostic
>van, scanned the neighborhood, then replaced most of the insulators on
>the block.
>
About 2 years to FIX. The excuse was "We will be renovating the
distribution in your area". Our area was a weird 1000V grid and could
not be cross connected int other neighborhoods that had the more
standard 1200V grid.
They replaced everything on the pole and power outages became rare.
, _
, | \ MKA: Steve Urbach
, | )erek No JUNK in my email please
, ____|_/ragonsclaw dragonsclawJUNK@JUNKmindspring.com
, / / / Running United Devices "Cure For Cancer" Project 24/7 Have you helped? http://www.grid.org
!