Cable modem goes out when I'm on my cell phone

[SmoochyTX]

Why does my cable modem go out when I get on my cell phone? It didn't happen with my old cell phone.

This cell phone: Samsung T319 (free phone from Tmobile)
This cable modem: Toshiba PCX2500-DAZ8821F Cable Modem connected via ethernet

What's causing this and, more importantly, how can I fix this?

 

[daveybrat]

Hmmmm.......never heard of that before. The only thing that sticks out to me is the cable modem. I looked it up on google and that thing looks old from what i can find.

You may want to buy your own cable modem to save money on renting and to get a much more reliable and faster modem.

The Motorola SB5120 is currently the best i've ever used and the latest model. You should be able to pick one up online between $50-$60 or less.

 

[SmoochyTX]

Yeah, I've had this cable modem since I got cable internet back in May 2003. I've never had any problems with it before and have been hesitant to switch (got it through Time Warner which is now Comcast in my area) because of bad things I hear about the modems being handed out.

I just connected the cable modem problem to the cell phone today even though it's been happening awhile. Usually I'd be away from the computer while on my cell phone and would sit down to check my email and my internet would be off. I just blamed it on Comcast (LOL!). But this afternoon, I got on my cell phone while sitting at the computer and the cable modem went almost immediately down. Got off the cell phone and it came right back up. Did it several times in a row and the exact same thing happened each time so it's definitely the interaction between the modem and the phone.

I couldn't find anything through Google so that's why I posted here. Weird problem. Any other ideas or explanations?

 

[birddseedd]

get an anti static bag and wrap it around the cable modem. could fix it.
See if you can get more highly braid insulated coax.
how far away does it effect. get a cat5 wire and put the modem in a closet somewhere where you dont talk on the phone.

 

[SmoochyTX]

The anti-static bag idea sounded weird but I tried it regardless. Didn't work. BTW, I won't put the modem in a closet because I want to see the pretty lights. LOL

Any other ideas?

 

[corkyg]

What cell phone carrier do you have? Sounds like EMI is possible. Different cell phones have different frequencies - i.e., Sprint is 1900 MHz. Others are 800 MHz. EMI can happen with harmonics of those. How old is your cell phone?

 

[SmoochyTX]

I am using Tmobile.

 

[Jschmuck2]

Ahhh I dunno guys - I'm smelling coincidence here. That modem would have to be SUPER sensitive to EMI to even...really....how would that even work? Technically, I mean. That phone would have to be throwing out Bruce Banner style gamma rays to interfere with a piece of hardware like a cable modem, wouldn't it?

 

[SmoochyTX]

Mr. Schmuck, I can guarantee you it's not a coincidence. I've repeated the situation over and over and it's definitely some kind of interference between the cable modem and cell phone.

 

[corkyg]

OK - T-Mobile's normal frequency is 1900 MHz - same as Sprint. IUt is possible for a leaky phone to send spurious emissions that have a harmonic that interferes with your modem when in close proximity.

Try this - get the help of a family member or friend, and see if there is a distance away from the modem where your cell phone no longer causes a problem. Sort of a "can you hear me now scenario." Find the critical distance. Then do it in different directions from the modem and you can create a pattern.

Another good test would be to bring in another cellphone and try it. If the same thing occurs, then chances are it is the modem that needs shielding. Try a basket or barrier of copper window screen grounded.

Since it didn't happen with your old cell phone, I suspect it is the new cellphone.

 

[piasabird]

Try Shielding around Cable Modem?

Call FCC and Complain against the vendor?

Maybe the Cable is not shielded enough or the signal gets in from your computer like a wireless card or something. Is the cable modem also wireless, or do you have wireless netwroking?

Maybe you can move your cable modem farther away or put a box or a steel pot over it or something like that. Try something like Aluminum Foil maybe. Copper pot?

Either that or try some interference like some a flourescent light.

Teach your friends to IM You.

The Cable modem does not have to be close to the computer. Mine is in another room, and I run a 20 Ft Network cable to it. You cable modem could even be in a closet.