T-mobile sim cards- why so many different styles?

[pdxrealtor]

I've gotten 3 different sim cards in the last couple of weeks. One came with a G2, it's got the wider gold contacts on it. The other is a replacement due to a lost phone and has a smaller foot print, then I got a new mytouch 4g and it is yet another design.

See pictures. they are all TM 9703, but all have different numbers on the front.


I ask this because the newest Mytouch, using the sim that cam in the box, is actually getting steady 3g when no HSPA is available while the other two sim cards I've used in both the mytouch and G2 have not yielded a 3g connection.

Anyone have any insight into this?

 

[bigleague4040]

I don't know about T-Mo as I've only had one SIM from them, but I know AT&T does the same thing, and the logos on the FRONT are different on all 3... To my knowledge, there are different versions of SIM cards, the newer of which have more encryption. That's what I've heard, I might be wrong, so don't quote me on that

 

[pdxrealtor]

Well I finally had the chance to work with both SIM cards in the same phone and I don't see any difference so far.....

 

[2FR35H]

Well I finally had the chance to work with both SIM cards in the same phone and I don't see any difference so far.....

You really shouldn't find any difference

I think T-mobile has this to make distinction between which phone can access what service. Kind of like how a Prepaid is different from Contract. Also some phones don't need access to 4G or other services of the sort being that they aren't fully capable so that can be another reason.

 

[scabbott]

As far as i know newer sim cards have the smaller gold contacts. But contract and pay as you go can be switched between sim so i dont think its to do with that. Still odd...

 

[DellyBelly]

You really shouldn't find any difference

I think T-mobile has this to make distinction between which phone can access what service. Kind of like how a Prepaid is different from Contract. Also some phones don't need access to 4G or other services of the sort being that they aren't fully capable so that can be another reason.

Theres definitely a difference; I'm in philly and they turned on HSPA+ and when at my apartment while on HSPA+ I get no MMS or Data/web (Still get texts and voice); however after leaving and going to normal 3G everything works fine (This is with original N1 SIM).

So yesterday I got an updated SIM card from Tmo and that fixed the problem without any other changes full speed data/web/mms at my apartment, so the revisions definitely affect certain service.

The original SIM was the one that came with my N1 on release, so if anyone else is having issues where they have HSPA+ turned on, that could be your issue.