I currently use a prepaid Samsung cell with GSM when I travel in Mexico under the Telcel network. I was wondering how wonderful it would be if I plugged the GSM card from the Samsung into my 8830WE. Would it work if I selected GSM under Network Options?
In other words, if someone called me on my Samsung number, would it ring on my 8830, while in Mexico on the Telcel network?

Yes, your SIM will work in your device. What you have to do is call sprint before you leave (usually a few days) and ask them to enable international roaming. Its a free service, and you wont get charged for anything. And Yes, your Telcel number will be on your blackberry. You wont get any data services unless you pay for it with Telcel but it will work

Sprint uses CDMA in Mexico, not GSM.......would that make a difference with the SIM card?

OP should be able to select the Telcel GSM network with his SIM.

I don't believe the advice here is correct. GSM in Mexico, like the US, is 850/1900, not 900/1800. I believe the GSM radio on the 8830 is 900/1800 only. Also, no one mentioned having unlocked the Sprint 8830 -- by default the 8830 would be locked to your carrier... even if the original poster were traveling to a European country with 900/1800 GSM, they'd need to unlock the phone before traveling.

BTW, to clarify, when I said they'd need to unlock before traveling, I meant they would need to unlock if they planned to use local (non-Sprint) sim cards with the device, as the original poster wants to do.

No. Sprint does not lock the SIM in the 8830.

There are many areas of CDMA coverage in Mexico as well. I recommend checking International Roaming.

Well I installed the Telcel prepaid phone SIM card that was in my little prepaid phone into my 8830. I am going to Mexico today and will try changing the Network Options to GSM only and see if I can use it as I was using my little Samsung Telcel prepaid phone.

To my understanding from speaking with people who have succesfully made an Iphone work on Telcel, it's not a 900/1800 frequency issue, but more of a having the phone unlocked issue. Now from what I've read thus far, the Sprint 8830 comes unlocked to my understanding right?

To clear up confusion, I have no problems roaming, making and receiving calls on thru Sprint while in Mexico. My issue is that the CDMA roaming is expensive. Which is why I carry a little Mexican Telcel prepaid Samsung phone that I use to call local Mexican numbers. It's much cheaper. What lured me to the 8830WE was the thought that I could stop carrying two phones while in Mexico.

I guess I'll see how it goes today and report back the results. I haven't called Sprint yet to enable International Roaming. I don't think it would make a difference since I wont be using the SIM card that came from Sprint anyway.

Well it didn't work

I changed network connections to GSM and it searched for for a GSM network for about 5-10 minutes and then said No Service.

I changed it to the GLOBAL and it went back to Sprint service roaming on the Mexican network with the little hazard symbol.

I have a feeling that this can be done, can anybody tell me how? Do I need to unlock the BB? I thought Sprint BBs were already unlocked? For those of you unsure of what I'm trying to do please read the previous thread. I basically want to have 2 phones in one.

Thanks,
Joe

Joe, the answer was provided earlier in the thread. (Post #5)
The GSM frequencies used my Mexican wireless carriers are not compatible with the 8830. It doesn't matter if the phone is unlocked.

GSM on the 8830 will not work in Mexico, for the same reasons that it will not function within the U.S.

I don't mean to be argumentative, I did read Post #5, however I also read conflicting posts such as, Sidsub & Sith_Apprentice's that hinted that it will work.
I did some digging with some contacts I have in Mexico and I think it can be done because I saw a Verizon Pearl that had been "unlocked" and working with a Telcel GSM sim card. They also unlock Iphones to make them work with Telcel. Another point to mention regarding the 8830 is that Telcel offers the 8830 for it's subscribers which tells me it shouldn't be a hardware issue rather a programming issue. After all the BB 8830 is manufactured in Mexico

I wonder if after I get it programmed to work on Telcel (if possible), if I will still have the ability to switch back to Sprint when I come across the border and swith the Network Mode back to 1XEV.

This is absolutely impossible.
The Verizon Pearl doesn't even have a SIM card slot. It's a CDMA phone... no GSM ability at all. There is no SIM card.
A Verizon Pearl, when used on any carrier, will be using CDMA.

The 8830 will work in CDMA mode on Telcel. It's not using GSM at all, because it's not possible.

Please try to understand this... the 8830, when used in Mexico or the US, is operating in CDMA mode. You'll get a 1X or 1XEV signal.
You won't be using GSM, or a SIM card at all.