stop gsm static

January 5, 2008 10:15 PM

How can I make the damn GSM clicking from my iphone stop attacking my baby monitor?

Does anyone know of a baby monitor that will not exhibit the damn clicking that is comes from my iphone?

Also, is there something I can do on the iphone side to stop the interference in all manner of devices, short of wrapping it completely in tinfoil?

http://en.wikipedia.org/wiki/GSM#Interference_with_audio_devices

posted by brent_h to technology (15 comments total)

Do you have wi-fi at home? Is the iPhone connected to the wi-fi? I know with my BlackBerry when I have the wi-fi radio on and associated with my home or work network the bursts affecting my speakers become very infrequent and less annoying.
posted by saraswati at 10:22 PM on January 5, 2008

That's what GSM phones do. Other than keeping it away from the baby monitor, there's really nothing you can do AND have the phone turned on/online at the same time.
posted by CommonSense at 10:25 PM on January 5, 2008

It's because the cables aren't magnetically shielded (I think). Unless you buy newer stuff, there's nothing you can do.

As an iPhone owner, I feel your pain.
posted by matty at 10:41 PM on January 5, 2008

Put it in airplane mode, thereby turning off the phone mechanism? Downside: you won't receive calls.
posted by MadamM at 10:42 PM on January 5, 2008

So THAT'S where the damn clicking is coming from on our baby monitor! We have an iPhone in the house too. I'm not sure "newer stuff" is the answer, since both baby monitor and iPhone are brand new. Is it possible to shield the cables yourself somehow?
posted by Joh at 11:43 PM on January 5, 2008

completely annoying in my car stereo as well.
posted by patricking at 11:49 PM on January 5, 2008

It's not just the iPhone - most cell phones will affect unshielded audio equipment. Microphones at lectures, computer speakers, etc.
posted by chrisamiller at 11:55 PM on January 5, 2008

No, there's nothing you can do about it save turning the phone off.
posted by rhizome at 11:57 PM on January 5, 2008

I haven't tried these myself but here are a couple of things that make sense to me:
1) Put the baby monitor in tin can. Make it really loud and close the lid. Can you still hear baby noises? Can you still heard GSM noises?
2) Wrap your baby monitor in some sort of wire mesh. Leave the antenna uncovered since you still need to receive baby noises. You can salvage this material from broken speaker and other audio shielded devices, but I think that window mesh might work too.
3) Take apart the baby monitor and solder a metal enclosure around the circuit board inside (basically, this is a better version of step 1). Maybe shield the wires going to the speaker.
posted by pantsrobot at 12:50 AM on January 6, 2008

Agreed, not an iPhone-only issue. Three things work for us: separating the devices enough (usually this means rooms away but if you crank the volume on the phone ringer there's some hope of hearing it); changing the frequency (meaning, the number of times per minute or whatever) with which your phone searches for data like email, phone messages, rss, weather, etc.; and having only one device on at a time. Or learn Morse Code and practice looking for hidden words and messages in the clicking.
posted by cocoagirl at 5:02 AM on January 6, 2008

That's what GSM phones do. Other than keeping it away from the baby monitor, there's really nothing you can do AND have the phone turned on/online at the same time.

There's a few things you can try. GSM operates on a time division principle - the radio channel is divided into time slots so that multiple users can share the same radio channel in the same cell. In order to accomplish this, a GSM phone sends a transmission "burst" in its assigned time slot - and turns its transmitter off otherwise. GSM does this a few hundred times per second - right in the audio band. What you are hearing in your baby monitor the transmitter in your phone turing on and off.

Radio signals get weaker as the inverse of distance (squared) between transmitter and receiver so the first thing to try is moving your phone as far away from your monitors as possible. (This is why putting a GSM phone on your dashboard is easily heard in your car's audio system, but in your pocket it's much less irritating.)

Another thing may be that your phone has a bad line of sight to the cell tower and has to transmit at a high power level. Moving it to another location, even if closer to one of the monitors, might also reduce the transmit power level (and thus the signal received at the monitor.)

Finally, try another brand of baby monitor - one that transmits a digital signal would be more or less immune to the interference created by your cell phone.
posted by three blind mice at 5:29 AM on January 6, 2008 [2 favorites]

The cookie-tin thing won't work. If it blocks the GSM signals, then it also blocks the baby-monitor signals. Sorry. (Unless you want quiet, of course, no matter the result.)
posted by cmiller at 6:55 AM on January 6, 2008

My wife and I both have the Motorola Razr. Hers is GSM, mine is CDMA. Her phone produces this issue with out stereo speakers, mine does not. Annoying, but luckily the range for this issue doesn't seem to be more than about 10 feet.
posted by spikeleemajortomdickandharryconnickjrmints at 8:33 AM on January 6, 2008

I have an iPhone and a digital monitor and don't have this problem. Not sure of the brand but my phone charges right next to it and this has never been an issue. I guess that I'm nthing getting another kind of monitor. Digital seems to be the way to go.
posted by pearlybob at 1:47 PM on January 6, 2008

I believe the newer (and very expensive) digital baby monitors may be the solution for you. My local baby store told me this would prevent interference with the wifi. You could buy one at Costco and then return it (you have six months, right?) if there are problems. Six months is plenty of time to sort things out.

FWIW, we had problems with my child's toy R/C garbage truck driving around every time we ate dinner. We figured out that it drove every time our preschooler spoke. My husband figured out that the baby monitor was picking up high-pitched voices and sending them to the receiver, but the receiver was on the same frequency as the R/C. I'm not sure that explains your iPhone problem, but you never know.
posted by acoutu at 3:29 PM on January 6, 2008 [1 favorite]