GSM Speaker Interfence (Was: AT&T raises unlisted number feeby 350-600%)

[email protected]lid wrote:
> In article <[email protected]>,
> John Higdon <[email protected]> wrote:
>
>> When my phone transmits, it makes a horrible buzz in my car radio...so I
>> know when it's talking. With almost clockwork precision, I can predict
>> when it is going to start chattering. At key places along the freeway,
>> at certain intersections, etc., it almost invariably starts making that
>> distinctive noise for about fifteen seconds. That has got to be draining
>> the battery.
>
> That's the first time I have ever heard anyone talk about this. This
> exact same thing happens with my Motorola Trac phone, whether or not
> there is an incoming call. I never knew cell phones would interfere with
> a car's audio system. I now turn the cell completely off when I'm
> listening to the radio/tape/CD/iPod in the car.

Here's a good article on it, including an explanation from Nokia.

"The ever-knowledgeable Keith Nowak, spokesperson for Nokia, explains it
as follows: "[[With GSM]] the RF transmitter is turned on/off at a fast
rate, and that 'pulsing' is often picked up by nearby devices that don't
have good RF shielding. In the case of GSM the pulse rate is 217 Hz,
which can be easily heard."

"http://www.smartdevicecentral.com/article/That+Crazy+GSM+Buzz/199379_1.aspx"

According to the article, the way to avoid this problem is to switch to
Verizon or Sprint (or one of the other CDMA carriers).

---

› See More: GSM Speaker Interfence (Was: AT&T raises unlisted number feeby 350-600%)

SMS wrote:
> [email protected]lid wrote:
>> In article <[email protected]>,
>> John Higdon <[email protected]> wrote:
>>
>>> When my phone transmits, it makes a horrible buzz in my car
>>> radio...so I know when it's talking. With almost clockwork precision,
>>> I can predict when it is going to start chattering. At key places
>>> along the freeway, at certain intersections, etc., it almost
>>> invariably starts making that distinctive noise for about fifteen
>>> seconds. That has got to be draining the battery.
>>
>> That's the first time I have ever heard anyone talk about this. This
>> exact same thing happens with my Motorola Trac phone, whether or not
>> there is an incoming call. I never knew cell phones would interfere
>> with a car's audio system. I now turn the cell completely off when I'm
>> listening to the radio/tape/CD/iPod in the car.
>
> Here's a good article on it, including an explanation from Nokia.
>
> "The ever-knowledgeable Keith Nowak, spokesperson for Nokia, explains it
> as follows: "[[With GSM]] the RF transmitter is turned on/off at a fast
> rate, and that 'pulsing' is often picked up by nearby devices that don't
> have good RF shielding. In the case of GSM the pulse rate is 217 Hz,
> which can be easily heard."
>
> "http://www.smartdevicecentral.com/article/That+Crazy+GSM+Buzz/199379_1.aspx"
>
>
> According to the article, the way to avoid this problem is to switch to
> Verizon or Sprint (or one of the other CDMA carriers).


....or install shielded speaker cabling and shielded speakers with proper
grounding of the shield. Viola!

--
jer
email reply - I am not a 'ten'

Jer wrote:

>> According to the article, the way to avoid this problem is to switch
>> to Verizon or Sprint (or one of the other CDMA carriers).
>
>
> ...or install shielded speaker cabling and shielded speakers with proper
> grounding of the shield. Viola!

It's pretty impractical to expect people to start disassembling their
vehicle in order to install shielded speakers and cable, and it won't
have any effect on vehicle speakers. It's coupling into the RF or IF
section of the radio receiver, not into the speakers or the speaker wiring.

For amplified computer speakers, it might help to use shielded cabling
and shield the enclosures.

It's much simpler to attack the source of the problem, than to use these
band-aid solutions.

Elmo P. Shagnasty wrote:
> In article <[email protected]>,
> SMS <[email protected]> wrote:
>
>> Here's a good article on it, including an explanation from Nokia.
>
> Well, there you have it. Navas will be the first one to tell you that
> you can't trust anything about Nokia, that you must kiss the ass of his
> beloved Motorola if you are to be anyone.

I doubt it. He likes Nokia ever since Nokia couldn't compete in the CDMA
handset market and made up their excuse for abandoning CDMA. Well
technically they didn't abandon CDMA, they abandoned designing their own
handsets for CDMA 2000 voice service.

SMS wrote:
> Jer wrote:
>
>>> According to the article, the way to avoid this problem is to switch
>>> to Verizon or Sprint (or one of the other CDMA carriers).
>>
>>
>> ...or install shielded speaker cabling and shielded speakers with
>> proper grounding of the shield. Viola!
>
> It's pretty impractical to expect people to start disassembling their
> vehicle in order to install shielded speakers and cable, and it won't
> have any effect on vehicle speakers. It's coupling into the RF or IF
> section of the radio receiver, not into the speakers or the speaker wiring.
>
> For amplified computer speakers, it might help to use shielded cabling
> and shield the enclosures.
>
> It's much simpler to attack the source of the problem, than to use these
> band-aid solutions.


I've never noticed the problem in a car, but I did when near my nephew's
PC - which got the shield fix for $2. As far as the car is concerned,
my figures put the IF on the lower end of the FM band, if it happens at
all. The nephew's car radio must be better shielded than others, and
given that, may use shielded speaker cables too.

--
jer
email reply - I am not a 'ten'

In article <[email protected]>,
Jer <[email protected]> wrote:

> ...or install shielded speaker cabling and shielded speakers with proper
> grounding of the shield. Viola!

That's probably the most useful suggestion to someone like me, but it's
easier just to turn off the phone. You know, if it were spark plug noise
(that's what I thought it was at first), I would just change the plugs.

In alt.cellular.verizon SMS <[email protected]> wrote:
>
> It's pretty impractical to expect people to start disassembling their
> vehicle in order to install shielded speakers and cable, and it won't
> have any effect on vehicle speakers. It's coupling into the RF or IF
> section of the radio receiver, not into the speakers or the speaker wiring.
>
> For amplified computer speakers, it might help to use shielded cabling
> and shield the enclosures.
>
> It's much simpler to attack the source of the problem, than to use these
> band-aid solutions.

It often affects wired and certain wireless telephones [i.e. landline FXS
port] and their is nothing that can be done to avoid it other than move your
GSM phone away from the phone. Quite annoying. I have called tech support
people from time to time and you can hear the GSM phone doing its routing
network check. "Sir, could you please move your phone away from your headset
or shut it off?". Simply asking them to move the phone works ... everybody is
aware it happens.


--
Thomas T. Veldhouse
Key Fingerprint: D281 77A5 63EE 82C5 5E68 00E4 7868 0ADC 4EFB 39F0