Cell phone and iMac noise??!!

[macdon401]

Hi , I have an Mac 1.8 20", 768 R ... is this strange.... when I turn my cell phone on or off, and while getting a call, if I am in the same room as my Mac it makes a very loud sound...kinda like a ray gun popping short burst's!!!
I dont really have my speakers on too loud but this signal comes through in a big way! I know it is connecting to a network but can this be harmful to the computer???
Thank you
R

 

[dllavaneras]

As far as I know, that only happens to GSM phones. My cell phone causes the same kind of interference, but I haven't seen any problems with my computer apart from the screen flickering when I get a SMS or a call.

 

[TBi]

It's just the GSM signal being picked up by the amplifier to the speakers. This amplifier has a constant gain so it will always be the same level no matter what the speakers are set to. The variable gain amp comes before it.

It's nothing to worry about, just annoying.

 

[shdwsclan]

GSM phones are usually the culprit because GSM frequency is so crappy but its so widely used. Isn't funny that all the crappy technologies come from Europe (220v, Pal, GSM400, GSM, GPRS). Well anyway, most gsm(TDMA) antennas are poorly classified by the FCC and therefore you get interference. CDMA uses a frequency of 2100 all around and you have no reception problems. Also CDMA uses 1 standard fequency worldwide instead of 5 like gsm(400,850,900,1800,1900). Leave it to europe to spread third world technologies.

 

[TBi]

GSM phones are usually the culprit because GSM frequency is so crappy but its so widely used. Isn't funny that all the crappy technologies come from Europe (220v, Pal, GSM400, GSM, GPRS). Well anyway, most gsm(TDMA) antennas are poorly classified by the FCC and therefore you get interference. CDMA uses a frequency of 2100 all around and you have no reception problems. Also CDMA uses 1 standard fequency worldwide instead of 5 like gsm(400,850,900,1800,1900). Leave it to europe to spread third world technologies.

A simple question. Where are you from?

And just so you know...

220V is more energy efficient than 110V, 110V is safer and that is why america used it.

Pal has a higher resolution leading to better picture quality than NTSC

GSM has different bands because some countries would not allow them to use the frequencies they'd normally use. The standard was introduced before mobile phones became really widespread and some goverments weren't too helpful.

What is wrong with GPRS?

 

[Koodauw]

GSM phones has the best sound quality over just about any other cellular phone. Its not crap.

On topic, the noise is normal, you'll actually here it a split second before your phone rings. Its a nice heads up. You'll get some false alarms though too.

 

[solvs]

I hear static and get interferance from my cell phone if I'm too close to my computers. It's normal. Annoying, but normal.

 

[adam-uk]

is this strange.... when I turn my cell phone on or off

Your phone, even if its not connected in a call, will - when you turn it on or off - report itself to the nearest celluar mast. Its to remind the system where you 'where' (if your turning it off) or where your new location is (if your turning the mobile on).

The same happens when a call occurs, however its more constant as voice data is being to and from your phone.

This all causes interferance with things like speakers and non DVI monitors / TV's.

 

[Poeben]

This is another reason why, aside from it being rude, theatres ask you to turn off your cell phone during performances. The cell phone signal can interfere with a multitude of devices in a theatre. The worst one I have personally experienced was the guitar player who left his cell phone on top of his amplifier. I seem to remember yelling something to the effect of "Someone go grab his phone and smash it."

 

[Warbrain]

If you think that's bad, my friends iMac G5 turns on when her phone rings. Not her cell phone, her regular land line phone that's hooked up to a wireless phone.

Must be something with the frequency that the phone runs on and it's interference with the computer.

Oh, and to the whole GSM complaint before...if CDMA is so great, why did I get no signal in downtown Chicago when I used CDMA yet I get a good signal with my Cingular service?

 

[solvs]

If you think that's bad, my friends iMac G5 turns on when her phone rings. Not her cell phone, her regular land line phone that's hooked up to a wireless phone.

Must be something with the frequency that the phone runs on and it's interference with the computer.

Oh, and to the whole GSM complaint before...if CDMA is so great, why did I get no signal in downtown Chicago when I used CDMA yet I get a good signal with my Cingular service?

If her iMac's modem is connected and set to wake on modem activity, that could be causing that.

CDMA doesn't have the same coverage as GSM. If there are a bunch of Cingular towers and no towers that carry CDMA, or interference from something else, that could explain the discrepancy.

 

[macdon401]

It's just the GSM signal being picked up by the amplifier to the speakers. This amplifier has a constant gain so it will always be the same level no matter what the speakers are set to. The variable gain amp comes before it.

It's nothing to worry about, just annoying.

So, if i didn't have external speakers this wouldn't happen...i seem to remember it did it on my old iMac and i had no external speakers then...??
Would it effect the mac's speakers as well?

 

[EricNau]

If her iMac's modem is connected and set to wake on modem activity, that could be causing that.

CDMA doesn't have the same coverage as GSM. If there are a bunch of Cingular towers and no towers that carry CDMA, or interference from something else, that could explain the discrepancy.

However, Verizon (CDMA) has better coverage than Cingular (GSM). So worldwide, GSM may have more coverage, but in the USA, CDMA has better coverage. So that doesn't explain it.

 

[solvs]

However, Verizon (CDMA) has better coverage than Cingular (GSM). So worldwide, GSM may have more coverage, but in the USA, CDMA has better coverage. So that doesn't explain it.

Didn't say which was "better", just that it didn't have the same coverage.

 

[Warbrain]

If her iMac's modem is connected and set to wake on modem activity, that could be causing that.

CDMA doesn't have the same coverage as GSM. If there are a bunch of Cingular towers and no towers that carry CDMA, or interference from something else, that could explain the discrepancy.

Hadn't thought about that as a possibility. I'll have to look at those settings.

But that doesn't explain why the TV goes screwy when she turns on her iMac. Granted, she's still using rabbit ears...

 

[solvs]

Hadn't thought about that as a possibility. I'll have to look at those settings.

But that doesn't explain why the TV goes screwy when she turns on her iMac. Granted, she's still using rabbit ears...

Magnetic interferance. My CRT used to shake if I turned on my TV and vice versa because they were so close together. Yeah, I don't know why either.

 

[EricNau]

Didn't say which was "better", just that it didn't have the same coverage.

by "better" I meant "more."

 

[EricNau]

Magnetic interferance. My CRT used to shake if I turned on my TV and vice versa because they were so close together. Yeah, I don't know why either.

I have an iMac G5 and a "rabbit ears" TV close by (with in 5 feet) and they don't do that. In the past I had a CRT where my iMac is now, and it did screw up the TV. I think the CRT causes that, so a flat panel shouldn't have that problem.