In my office we often experience instances of a "galloping" sort of buzz
periodically coming from the PC speakers near co-workers who have Cingular
GSM cell phones. A preliminary Web search turns up many instances of this
problem. My understanding is that these phones periodically communicate with
the network, and during these brief bursts the carrier is modulated at
around 200 Hz resulting is a clear, repeatable buzz pattern. How is this
buzz getting into the PC speaker amplifier, and, more importantly, how can
it be prevented?

Thanks,
Doug

You could;

1) Try different makes of speakers until you find some that are not as
susceptible to the interference. Ones with metal cases might be better
shielded.
2) Move the speakers to a location further from the phones. Like placing
them on the floor under the desks.
3) Buy snap-on ferrite chokes from Radio Shack and put them on the audio
and power cables going into the speaker amplifiers.

The latest theory on the disappearing bee populations is that
electro-magnetic cell phone emissions are disorienting the bees. Makes
you kind of wonder doesn't it?

DougSlug wrote:

In my office we often experience instances of a "galloping" sort of buzz
periodically coming from the PC speakers near co-workers who have Cingular
GSM cell phones. A preliminary Web search turns up many instances of this
problem. My understanding is that these phones periodically communicate with
the network, and during these brief bursts the carrier is modulated at
around 200 Hz resulting is a clear, repeatable buzz pattern. How is this
buzz getting into the PC speaker amplifier, and, more importantly, how can
it be prevented?

Thanks,
Doug





--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

"DougSlug" wrote in message
...
In my office we often experience instances of a "galloping" sort of buzz
periodically coming from the PC speakers near co-workers who have Cingular
GSM cell phones. A preliminary Web search turns up many instances of this
problem. My understanding is that these phones periodically communicate
with
the network, and during these brief bursts the carrier is modulated at
around 200 Hz resulting is a clear, repeatable buzz pattern. How is this
buzz getting into the PC speaker amplifier, and, more importantly, how can
it be prevented?

The phones do communicate regularly with the network. The network must be
constantly updated with whose phones are switched on and which cell tower is
providing service. (It would be impractical to ring you for an incoming
call if the network had to query every tower in the world, "Hey, I have a
call for DougSlug. Who has him???")

This is a surprisingly common form of Electromagnetic Interference (EMI).
The RF is being coupled into the wiring and changing the conduction of the
small transistor amplifier inside one of the speakers, the one with the
light and switches.

At work, I usually know when my co-workers cell phone will ring, because MY
speakers emit a bup-bup-bup-buzz right before the ring. See, he usually
keeps his phone next to the cubicle panel on his side, but by chance just
inches away from my speakers. I have heard the same thing on TV, when a
performer is wearing both a wireless mike and a cell phone.

Rerouting the wires or relocating the phone is the obvious solution, as
distance is your friend in these cases. Otherwise, adding a few ferrites to
the speaker lines may work. They present a high impedance to RF traveling
along the wires, but have negligible effect on the audio signal. (You
probably already own ferrites pre-installed in some of your wiring -- you
just didn't know it. The various connecting cords for your camcorder have
those fat lumps in them. Those are ferrites.

Ferrites are available for purchase in many radio and electronic stores in a
form which closes, clamshell-style around the wire. You put two or three
along the wire and *presto* no more buzz. Wrapping the wire multiple times
around a ferrite before snapping it closed can help immensely. (This
assumes you have some available slack in the speaker wires.)

Some theory he http://en.wikipedia.org/wiki/Choke_(electronics)

http://www.radioshack.com/sm-snap-to...-pi-2103222.ht
ml has them, but overpriced compared to the $1.00 apiece I pay for them at
the San Diego-area ham radio swap meet.

Also around a dollar he
http://www.mouser.com/search/Refine....rPartNumber%7C
0%7C%7CP_SField

I cannot advise you what to buy, but If you spring for a few of each at the
$1.00 level, I really think you'll find something that works. Shipping is
extra but Mouser will sell in small quantities. Thanks, Mouser.

Good luck. If you go this route, please let us know what worked and how
many. TKS.

"DougSlug" wrote in message
...
In my office we often experience instances of a "galloping" sort of buzz
periodically coming from the PC speakers near co-workers who have Cingular
GSM cell phones. A preliminary Web search turns up many instances of this
problem. My understanding is that these phones periodically communicate
with the network, and during these brief bursts the carrier is modulated
at around 200 Hz resulting is a clear, repeatable buzz pattern. How is
this buzz getting into the PC speaker amplifier, and, more importantly,
how can it be prevented?

Thanks,
Doug

Turning off the phones, the PC speakers, the computers or removing the
electrical supply to the building or city would work if there are no
provisions for backup power...But I have a suspicion that this was not the
answer you seek

You will notice that various noise is generated by any electronics
network utilising microprocessors, such as cell phones ( or any
transceivers ), phone switches/PBX, computer/FAX devices, and security
equipment, all of which emit or generate RF signals ,whether they are
super-imposed with audio frequencies or not. This usually includes most
micro-processor-controlled electronics...harmonics will bleed through into
your regular phones, TVs, scanners, PCs, any amplifiers, and AM/FM/LW/SW
radio equipment either internally or from being in close proximity to any
other electronics devices too.

That's why you aren't allowed to use cell phones of any type on any
network in hospitals where you might interfere with someone's pacemaker or
diagnostic equipment, and testing has provided facts to back up the claims
with viable statistics. The hospital administrations have decided that the
best way to cure the possibility of interference from
outside/inside/portable sources is to turn " OFF " the device which has the
potential to cause it. Portable cell phones provide an ever changing source
of interference with many variables involved as the carrier of the device
moves about, and this can cause unpredictable consequences.

If you're computers are not losing or misinterpreting data input/output,
then you might want to live with the slight noise problem and let the cell
phone industry survive and thrive.

Jack

The phones do communicate regularly with the network. The network must be
constantly updated with whose phones are switched on and which cell tower
is
providing service. (It would be impractical to ring you for an incoming
call if the network had to query every tower in the world, "Hey, I have a
call for DougSlug. Who has him???")

This is a surprisingly common form of Electromagnetic Interference (EMI).
The RF is being coupled into the wiring and changing the conduction of the
small transistor amplifier inside one of the speakers, the one with the
light and switches.

At work, I usually know when my co-workers cell phone will ring, because
MY
speakers emit a bup-bup-bup-buzz right before the ring. See, he usually
keeps his phone next to the cubicle panel on his side, but by chance just
inches away from my speakers. I have heard the same thing on TV, when a
performer is wearing both a wireless mike and a cell phone.


I got my first cell phone about 8 months ago and it didn't take long for me
to run into this. At work I have headphones on most of the time, listening
either to AM radio or to an audio cassette (both from the same Walkman-type
unit). Those brief digital bursts occur about every 10 minutes and if the
headphone cord is close to my cell phone, the sounds can be very loud in the
headphones. I've even heard the bursts coming from the speakers connected
to my home stereo, with the audio source not running (connected to CD
player, but volume is still turned up), and the cell phone is lying on the
table in the next room.

As you said, with a bit of practice I can tell if my cell phone is actually
about to ring or is just checking in with the network. A couple of days ago
the digital pattern was of a type I'd never heard before and when I looked
down to look at my phone, I found that someone had sent me a text message (a
feature I normally don't use).

I mentioned this recently to a friend of mine and he told me about a
somewhat similar experience that happened to him when he was a kid, about 25
years ago. He lived in a house with somewhat ancient telephone wiring and,
for some reason he never did figure out, the telephone would emit a very
brief "ghost ring" right before it would ring for real. That is, it was an
electromechanical phone (this was early 1970s) and before the first
"genuine" ring, the phone would first put out one very brief "ping."
Apparently there was something in the telephone network that would send out
a very brief "pip" that would ding the bell just once (the actual ring is a
constant string of pulses). As a boy in his early teens, my friend noticed
this but said nothing about it to anyone else. Whenever he was in the house
and heard that brief "ping," he knew that the telephone would ring a couple
of seconds later. He had an aunt who was loud, obnoxious, stupid, five feet
in all directions, and totally clueless about technology; whenever she'd
come by the house for a visit, my friend would terrorize her by hollering
"PHONE'S GONNA RING!!!!" about two seconds before it actually did. She
never noticed the "ghost pings." She never did catch on and was totally
convinced that he was possessed.
Some time later, the tables got turned on him, briefly. Whenever
he was in the house alone, with total quiet, sometimes he could hear voices
and couldn't figure out where they were coming from. It wasn't constant,
either. Very faint whispers. Very strange. They seemed to be coming from
the kitchen and he couldn't quite bring himself to believe that he was
hearing ghosts. He finally got the clue he needed late one night when he
raided the refrigerator and distinctly heard the '70s song "The Sound of
Philadelphia" coming from nowhere. He couldn't picture a bunch of ghosts
sitting around a kitchen playing disco music, so he poked around and finally
discovered the source of all this: a flashlight! It was an old-style
flashlight, with two batteries, an incandescent bulb, a metal case, and a
big magnet so it would stick to the fridge. Apparently the spring inside
the flashlight was forming a junction diode and was rectifying an AM radio
station signal. The "voices" were apparently from a talk show during
certain hours.

alot of this can also be caused by inductive coupling
to speaker or headphone coils.

mike

"Matt J. McCullar" wrote in message
t...

The phones do communicate regularly with the network. The network must
be
constantly updated with whose phones are switched on and which cell tower
is
providing service. (It would be impractical to ring you for an incoming
call if the network had to query every tower in the world, "Hey, I have a
call for DougSlug. Who has him???")

This is a surprisingly common form of Electromagnetic Interference (EMI).
The RF is being coupled into the wiring and changing the conduction of
the
small transistor amplifier inside one of the speakers, the one with the
light and switches.

At work, I usually know when my co-workers cell phone will ring, because
MY
speakers emit a bup-bup-bup-buzz right before the ring. See, he usually
keeps his phone next to the cubicle panel on his side, but by chance just
inches away from my speakers. I have heard the same thing on TV, when a
performer is wearing both a wireless mike and a cell phone.


I got my first cell phone about 8 months ago and it didn't take long for
me
to run into this. At work I have headphones on most of the time,
listening
either to AM radio or to an audio cassette (both from the same
Walkman-type
unit). Those brief digital bursts occur about every 10 minutes and if the
headphone cord is close to my cell phone, the sounds can be very loud in
the
headphones. I've even heard the bursts coming from the speakers connected
to my home stereo, with the audio source not running (connected to CD
player, but volume is still turned up), and the cell phone is lying on the
table in the next room.

As you said, with a bit of practice I can tell if my cell phone is
actually
about to ring or is just checking in with the network. A couple of days
ago
the digital pattern was of a type I'd never heard before and when I looked
down to look at my phone, I found that someone had sent me a text message
(a
feature I normally don't use).

I mentioned this recently to a friend of mine and he told me about a
somewhat similar experience that happened to him when he was a kid, about
25
years ago. He lived in a house with somewhat ancient telephone wiring
and,
for some reason he never did figure out, the telephone would emit a very
brief "ghost ring" right before it would ring for real. That is, it was
an
electromechanical phone (this was early 1970s) and before the first
"genuine" ring, the phone would first put out one very brief "ping."
Apparently there was something in the telephone network that would send
out
a very brief "pip" that would ding the bell just once (the actual ring is
a
constant string of pulses). As a boy in his early teens, my friend
noticed
this but said nothing about it to anyone else. Whenever he was in the
house
and heard that brief "ping," he knew that the telephone would ring a
couple
of seconds later. He had an aunt who was loud, obnoxious, stupid, five
feet
in all directions, and totally clueless about technology; whenever she'd
come by the house for a visit, my friend would terrorize her by hollering
"PHONE'S GONNA RING!!!!" about two seconds before it actually did. She
never noticed the "ghost pings." She never did catch on and was totally
convinced that he was possessed.
Some time later, the tables got turned on him, briefly. Whenever
he was in the house alone, with total quiet, sometimes he could hear
voices
and couldn't figure out where they were coming from. It wasn't constant,
either. Very faint whispers. Very strange. They seemed to be coming
from
the kitchen and he couldn't quite bring himself to believe that he was
hearing ghosts. He finally got the clue he needed late one night when he
raided the refrigerator and distinctly heard the '70s song "The Sound of
Philadelphia" coming from nowhere. He couldn't picture a bunch of ghosts
sitting around a kitchen playing disco music, so he poked around and
finally
discovered the source of all this: a flashlight! It was an old-style
flashlight, with two batteries, an incandescent bulb, a metal case, and a
big magnet so it would stick to the fridge. Apparently the spring inside
the flashlight was forming a junction diode and was rectifying an AM radio
station signal. The "voices" were apparently from a talk show during
certain hours.

"Matt J. McCullar" wrote in message
t...


... a friend of mine and he told me about a
somewhat similar experience that happened to him when he was a kid, about
25
years ago. He lived in a house with somewhat ancient telephone wiring
and,
for some reason he never did figure out, the telephone would emit a very
brief "ghost ring" right before it would ring for real. That is, it was
an
electromechanical phone (this was early 1970s) and before the first
"genuine" ring, the phone would first put out one very brief "ping."
Apparently there was something in the telephone network that would send
out
a very brief "pip" that would ding the bell just once (the actual ring is
a
constant string of pulses).

I had an El Cheapo phone on my nightstand for years. It was a one-piece
unit that I laid face-down to hang up. It always gave out a chirp right
before the ring, which I imagine was related to the ghost ring your friend
heard.

In addition, that phone emitted an offbeat three chirp pattern every evening
about 10:45. If my wife and I were there together, one of us would usually
wisecrack about the FBI and phone taps. I imagine it had something to do
with testing the line. I had forgetten all about that.

"Sal M. Onella" wrote in message
...

I had an El Cheapo phone on my nightstand for years. It was a one-piece
unit that I laid face-down to hang up. It always gave out a chirp right
before the ring, which I imagine was related to the ghost ring your friend
heard.

In addition, that phone emitted an offbeat three chirp pattern every
evening
about 10:45. If my wife and I were there together, one of us would
usually
wisecrack about the FBI and phone taps. I imagine it had something to do
with testing the line. I had forgetten all about that.



I recall during my teen years in Fort Worth, TX (Southwestern Bell) in the
mid-80s, during the summer months I would stay up for most of the night. I
had one of those el-cheapo electronic handheld phones in my room and it
always emitted a quick chirp at the same time each night: 2:10 a.m., without
fail! My guess is that it was responding to some high-voltage blip sent
down the network by the phone company for maintenance tasks or something.
Cecil Adams covered this topic in his column "The Straight Dope."

On Apr 29, 7:22 am, "Matt J. McCullar" wrote:
"Sal M. Onella" wrote in ...



I had an El Cheapo phone on my nightstand for years. It was a one-piece
unit that I laid face-down to hang up. It always gave out a chirp right
before the ring, which I imagine was related to the ghost ring your friend
heard.

In addition, that phone emitted an offbeat three chirp pattern every
evening
about 10:45. If my wife and I were there together, one of us would
usually
wisecrack about the FBI and phone taps. I imagine it had something to do
with testing the line. I had forgotten all about that.

I recall during my teen years in Fort Worth, TX (Southwestern Bell) in the
mid-80s, during the summer months I would stay up for most of the night. I
had one of those el-cheapo electronic handheld phones in my room and it
always emitted a quick chirp at the same time each night: 2:10 a.m., without
fail! My guess is that it was responding to some high-voltage blip sent
down the network by the phone company for maintenance tasks or something.
Cecil Adams covered this topic in his column "The Straight Dope."

Re telephones (old time dial type).
When your phone was 'on the hook' (no calls in progress) there was
typically a steady negative 48 volts on one side of the line pair and
zero volts on the other side of the line from either a balanced or
unbalanced 'line' relay. When you picked up the phone to make a call
the relay/s would spring into action and connect you dial tone etc.
When someone called YOU the line relay/s were disconnected and another
circuit set up by the person who dialled your number, prepared to
supply AC ringing to your line to ring the phone. However that supply
also had a DC component so that when you answered DC current would
flow, cut off the ringing and energise the microphone in your phone.
many different step-by-step systems, panel systems and crossbar but
the basic 'line' conditions were somewhat as described. In North
America the ringing was/is typically a 2 second burst fol owed by a 4
second break, at frequency of around 20 hertz. In other countries it
was often a sort of double burst of ringing followed by 4 second
break. So each 'cycle' of rings takes about 6 seconds. Something
remember if you are sitting on the can etc. when it rings!
So if the ringer bell or the ring-chirper was sensitive to small
changes in voltage (aka cheap or maladjusted phone) there was
definitely a possibility of a slight change of voltage on the line as
the dial office equipment set up and prepared to ring your phone.
Some of those el-cheapo phones were horrible; in one case they damped
down a fireman's line so badly that he didn't get emergency calls. The
cause was two cheap phones supplied with magazine subscriptions to his
two sons, who unwittingly hooked them up and stopped his main phone
from ringing. Cost our telephone company several hours/days of effort
to find out why an essential fireman's phone didn't work when every
other phone around his area was OK. But we did so cos his service was
important. Not so sure these days of competition anyone would bother;
it might be a case of 'Service OK leaving here. YOU have a problem'!
Oh; another radio related el-cheapo phone item! When we built our
first house the only service available in the area was one party on a
four party line! One of the other parties had a cheap phone on an
unsteady cheap metal stand and its handset kept falling off. One
Sunday trying to make a call and very frustrated I eventually played a
religious broadcast (of another denomination than theirs) as loud as
possible down the telephone line. Listening occasionally between burst
of loud hymn music one could hear "Where's that music coming
from ................. " comments and, ultimately the phone put back
on hook. Finally I could make my work related call!
Make sure you have fun out there!

On Apr 29, 7:22 am, "Matt J. McCullar" wrote:
"Sal M. Onella" wrote in ...



I had an El Cheapo phone on my nightstand for years. It was a one-piece
unit that I laid face-down to hang up. It always gave out a chirp right
before the ring, which I imagine was related to the ghost ring your friend
heard.

In addition, that phone emitted an offbeat three chirp pattern every
evening
about 10:45. If my wife and I were there together, one of us would
usually
wisecrack about the FBI and phone taps. I imagine it had something to do
with testing the line. I had forgetten all about that.

I recall during my teen years in Fort Worth, TX (Southwestern Bell) in the
mid-80s, during the summer months I would stay up for most of the night. I
had one of those el-cheapo electronic handheld phones in my room and it
always emitted a quick chirp at the same time each night: 2:10 a.m., without
fail! My guess is that it was responding to some high-voltage blip sent
down the network by the phone company for maintenance tasks or something.
Cecil Adams covered this topic in his column "The Straight Dope."

And oh yes; some telephone systems had 'Routiners' or 'Line Insulation
Testers' that would typically test through all the lines often late at
night when there are/were few calls and identify any leakage due to
wet cables and other non-normal conditions etc. two such incidents
were when a member of a telephone company vice president's family left
a phone outside in the rain and another when someone washed their
telephone set in the kitchen sink and put it aside to dry, without
unplugging it!
Keep looking for the ironic and the humorous.