Incoming call causes static on PC speakers

My cell phone (Motorola, Cingular) happened to be sitting next to my
workstation (it's usually in the other room) when a call came it. The
PC speakers went nuts. They started putting out fairly loud
klaxon-like pulsing sounds.

I tried calling that cell phone and another one and the same thing
happens.

The sound starts with a single pulse followed by 4-5 sets of 3 pulses,
then it's solid statis-like tone until the phone is answered or it
goes to voicemail.

If I move the phone across the room, it doesn't happen.

However, if I call the cell phone from a land line phone, I can hear
the same sounds in the earpiece or on the speaker phone, but much
softer.

What's causing this?

Are my cell phones malfunctioning?

--
For email, use [email protected]

---

› See More: Incoming call causes static on PC speakers

"LurfysMa" <[email protected]> wrote in message
> My cell phone (Motorola, Cingular) happened to be sitting next to my
> workstation (it's usually in the other room) when a call came it. The
> PC speakers went nuts. They started putting out fairly loud
> klaxon-like pulsing sounds.
> <snip>
> What's causing this?
>
> Are my cell phones malfunctioning?
>

JoshIII responded:
Bill Radio (I think it was) gave a full explanation of the differences in
GSM/TDMA vs CDMA modulation schemes on this very same subject posted a
couple of months back. If I can find his response, I will repost.

But it suffices to recap, only GSM and TDMA cellphones cause this problem,
because they transmit with pulses (kinda like a radar) during calls. CDMA
phones transmit continuously during calls, so PC speakers (specifically the
audio amplifier circuit in the PC speakers) are not affected as much by RF
interference from CDMA cellphones.

So in answer to your concerns, no your cellphone is not malfunctioning.
Just keep your GSM/TDMA cellphone away from unfiltered audio amplifiers like
PC speakers, hearing aids, speaker phones, and IPods in the future.

JoshIII, 11 NOV 05
upstate south carolina
[email protected]
Activating a TracFone soon? Get an email referral from a
TracFone user before you activate and you'll both receive
100 Free airtime minutes! See the website listed below for
details for a free phone and free airtime minutes from TracFone:
http://pasofinosc.tripod.com

On Fri, 11 Nov 2005, at 07:53:56 [GMT -0800] (02:53:56 Saturday, 12 November
2005 where I live) "LurfysMa" wrote:

> My cell phone (Motorola, Cingular) happened to be sitting next to my
> workstation (it's usually in the other room) when a call came it. The
> PC speakers went nuts. They started putting out fairly loud
> klaxon-like pulsing sounds.

Just move the phone. A characteristic "feature" of GSM phones.

LurfysMa wrote:
> My cell phone (Motorola, Cingular) happened to be sitting next to my
> workstation (it's usually in the other room) when a call came it. The
> PC speakers went nuts. They started putting out fairly loud
> klaxon-like pulsing sounds.

Switch to Verizon or Sprint.

On Fri, 11 Nov 2005 14:15:45 -0500, "JoshIII"
<[email protected]> wrote:

>"LurfysMa" <[email protected]> wrote in message
>> My cell phone (Motorola, Cingular) happened to be sitting next to my
>> workstation (it's usually in the other room) when a call came it. The
>> PC speakers went nuts. They started putting out fairly loud
>> klaxon-like pulsing sounds.
>> <snip>
>> What's causing this?
>>
>> Are my cell phones malfunctioning?
>>
>
>JoshIII responded:
>Bill Radio (I think it was) gave a full explanation of the differences in
>GSM/TDMA vs CDMA modulation schemes on this very same subject posted a
>couple of months back. If I can find his response, I will repost.
>
>But it suffices to recap, only GSM and TDMA cellphones cause this problem,
>because they transmit with pulses (kinda like a radar) during calls. CDMA
>phones transmit continuously during calls, so PC speakers (specifically the
>audio amplifier circuit in the PC speakers) are not affected as much by RF
>interference from CDMA cellphones.
>
>So in answer to your concerns, no your cellphone is not malfunctioning.
>Just keep your GSM/TDMA cellphone away from unfiltered audio amplifiers like
>PC speakers, hearing aids, speaker phones, and IPods in the future.
>
>JoshIII, 11 NOV 05
>upstate south carolina
>[email protected]
>Activating a TracFone soon? Get an email referral from a
>TracFone user before you activate and you'll both receive
>100 Free airtime minutes! See the website listed below for
>details for a free phone and free airtime minutes from TracFone:
>http://pasofinosc.tripod.com

Thanks for the info. Keeping the cell phone a few feet away seems to
solve the problem.

--
For email, use [email protected]

I used to find this happened with the radio in my car as well, so I
always knew when a call was coming in before the phone rang. Problem
was that a phone in a car alongside would also cause it sometimes...


--
Ralph5407