AT&T GoPhone SIM Compatibility Issues

[PhotoJim]

Originally Posted by Bossman

I will not call it crappy AT&T coverage. This certainly sounds like, as already mentioned, your phone is NOT quadband. It's missing the 850 band that AT&T uses heavily.

My experience with my supposedly quandband dual-sim chinese phone is that, ONLY sim slot 1 on my phone has the 850 band. The sim slot 2 almost always latches onto tmobile regardless of the sim I put in it. I tested it with a number of reaming sims I have. When I put my AT&T sim in it, there was barely any signal.

Interesting theory. I have the same four-SIM phone that gadgetken has, and I notice slots 3 and 4 seem to park on 1900 MHz whereas slots one and two park on 850 MHz. (I'm in Saskatchewan, Canada, and the only 2G coverage here is Rogers), so it's entirely possible that slots 3 and 4 in my phone lack 850 MHz. A person would have to go somewhere where a carrier has 850 MHz but no 1900 MHz coverage to know for sure.

[Roti2000]

Interesting, Bossman & akraus -- So the places where I CAN get AT&T coverage with this ostensibly Quad Band phone means that it is picking up the signal on GSM-1900?

It will be interesting to see what happens in Mexico--if wikipedia is to believed, Telcel uses 850 for 3g and hasn't rolled it out yet in the area where I'm headed.

So, theoretically, I guess, it should connect via GSM-1900.

Does anyone have any leads on reliable dual-sim quad-bands? I may try and do an exchange/return with focalprice.com if i have bad luck in Mexico.

I travel down there a lot, and many of the places I normally go around Mexico City are in Telcel 3g territory.

[GadgetKen]

Have had good luck with a dual sim quad band MFU V200 phone. Simple features, works well, very sturdy. Very basic though with a camera/video camera, MP3/MP4 player, FM stereo...no wifi, no alphanumeric keyboard, no TV, no touchscreen. But it does the job.

For a phone purchased from the US, lowest risk would probably be a Beyond E-Tech Duet dual sim phone. Only maker I'm aware of that has dual sim phones that are US FCC registered. You could also try before you buy at a store. Can be bought from several dealers including: Search Results for duet phone at JR.com They also have one of the lowest SAR ratings of any phone officially sold in the US: Other manufacturers cell phone radiation chart - CNET Reviews

[akraus88]

Originally Posted by Roti2000

Interesting, Bossman & akraus -- So the places where I CAN get AT&T coverage with this ostensibly Quad Band phone means that it is picking up the signal on GSM-1900?

It will be interesting to see what happens in Mexico--if wikipedia is to believed, Telcel uses 850 for 3g and hasn't rolled it out yet in the area where I'm headed.

So, theoretically, I guess, it should connect via GSM-1900.

Does anyone have any leads on reliable dual-sim quad-bands? I may try and do an exchange/return with focalprice.com if i have bad luck in Mexico.

I travel down there a lot, and many of the places I normally go around Mexico City are in Telcel 3g territory.

In Mexico the 1900 band will work great. 3g is a newer techbology, so wherever the have 850-3g, they have 1900-2g.

Side note: you cannot call with the att SIM in Mexico to any place other than US/Canada/Mexico.