iPhone Radio Interference

At 3:06 AM -0700 9/12/07, Nick Pappas wrote:
>iPhones seem to generate a horrendous amount of noise on systems that
>have external speakers. It's not a continuous thing - short bursts of
>pulses.
>
>On one Mac with external speakers, it seems to be impossible to
>soften the noise with the volume control. I have to unplug the power
>to the speakers to get rid of the sound.
>
>I seem to have a choice - my iPhone or external speakers.
>
>Is anyone else experiencing this?
>
>Surprised I have not seen it mentioned anywhere.


It's a GSM problem not exclusive to the iPhone. Treo and Blackberry
owners have the same problem.

Try moving the phone away from your speakers (or telephone).

I searched "gsm interference" and one of the hits was fairly informative:

<http://blogs.pcworld.com/techlog/archives/000622.html>


Regards,

Ken P.

On Sep 12, 2007, at 3:06 AM, Nick Pappas wrote:

> I seem to have a choice - my iPhone or external speakers.
>
> Is anyone else experiencing this?
>
> Surprised I have not seen it mentioned anywhere.

All GSM phones do this to varying degrees and have "since the
beginning", which is why I suspect you haven't seen it mentioned wrt
to the iPhone before (i.e. it's old news to many people and not
unique to the iPhone). Google "gsm speaker interference" for 348,000
hits on the subject.

- Todd

On Sep 12, 2007, at 6:06 AM, Nick Pappas wrote:

> Is anyone else experiencing this?

Everyone with a functioning GSM phone experiences this from time to
time.

It's called "TMDA Interference", and is an unavoidable side effect of
how GSM phones work.

Apparently it either doesn't happen, or is much less noticeable, with
Verizon's CDMA phones, but nearly all GSM phones [AT&T, T-Mobile,
etc] are susceptible to it.

It happens any time the phone communicates with the cellular tower,
and is part of why the iPhone doesn't work with all the dock-
connector speakers that standard iPods use -- most speakers will
relay that squawking noise whenever the phone is in the dock, or even
just near it.

A Google search for "TMDA Interference" brings up lots and lots and
lots of hits on the subject:

http://www.google.com/search?q=%22tdma+interference%22

Interestingly, it also seems to be a problem for radio astronomy:

http://citeseer.ist.psu.edu/227594.html
http://citeseer.ist.psu.edu/261597.html


--
Chris Devers

On 12-Sep-2007, at 04:06, Nick Pappas wrote:
> iPhones seem to generate a horrendous amount of noise on systems that
> have external speakers. It's not a continuous thing - short bursts of
> pulses.
>
> On one Mac with external speakers, it seems to be impossible to
> soften the noise with the volume control. I have to unplug the power
> to the speakers to get rid of the sound.

A friend of mine has the exact same problem with his RAZR. His
wife's RAZR doesn't cause the issue. Other than that, the RAZRs are
identical, work fine, and were bought at exactly the same time.


--
"Yes," said the skull. "Quit while you're a head, that's what I say."

Your cell phone gets a locating signal every 6 (I think) seconds. That signal, as well as when you get a call, is what causes the interference. It seems normal to me, because my 3 previous AT&T/Cingular phones did exactly the same thing as the iPhone. They were all Motorolas.

John

On 12/09/2007 10:06 PM, "Nick Pappas" <ngpappasnii.net> spake thus:

> Is anyone else experiencing this?
>
> Surprised I have not seen it mentioned anywhere.

Probably because it's pretty much normal with most cell phones (certainly in
my experience). Certainly my Sony Ericsson does the same thing to external
speakers. I think it's basically the phone negotiating with the network when
a connection starts up (such as an incoming/outgoing call or text). They
will also occasionally check with the network anyway, which means you get it
happening semi-randomly as well.

I remember when I first got my current phone, I was getting it at home,
quite loud, and I couldn't figure out where it was coming from until I
remembered that my CRT (since replaced) had built in speakers. I didn't
actually use them, which was why I didn't think of them at first. Turning
the volume down didn't help, and in the end the only solution was to shove a
spare plug into the headphone jack.

I guess the loudness of the effect varies from phone to phone, and probably
depends on the network type as well (mine's GSM). Short of keeping your
iPhone away from the computer or enclosing your speakers in a Faraday cage,
I don't know that there's much you can really do about it :)

--
Nigel Stanger, Dunedin, NEW ZEALAND.
http://xri.net/=nigel.stanger

> On Sep 12, 2007, at 5:06 AM, Nick Pappas wrote:
>
> iPhones seem to generate a horrendous amount of noise on systems that
> have external speakers. It's not a continuous thing - short bursts of
> pulses.

This seems to be due to the bluetooth. If you turn on the Airplane
mode, it goes away (making the iPhone near useless, in my opinion). I
say Bluetooth over WiFi as I had a Sony Ericsson cell phone that
would do a similar thing to my radio speakers at home. Th iPhone is
much worse, though.

Ray

At 10:48 PM -0700 9/12/07, Ray Kloss wrote:
>>On Sep 12, 2007, at 5:06 AM, Nick Pappas wrote:
>>
>>iPhones seem to generate a horrendous amount of noise on systems that
>>have external speakers. It's not a continuous thing - short bursts of
>>pulses.
>
>This seems to be due to the Bluetooth. If you turn on the Airplane
>mode, it goes away (making the iPhone near useless, in my opinion). I
>say Bluetooth over WiFi as I had a Sony Ericsson cell phone that
>would do a similar thing to my radio speakers at home. Th iPhone is
>much worse, though.

It is *not* due to Bluetooth.

BTW, Airplane Mode appears to shut off all comm: both GSM and
Bluetooth, as well as 802.11.

Finally, things like GSM chatter are why we all have to turn off our
cell phones on airplanes (or use Airplane Mode). The concern is that
those two hundred phones sqwaking about for a cell tower will
interfere with the plane's communication systems.

Ken P.