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View Full Version : Proof that JAM radio 850mhz is firmware Based?


jehlinger
13th April 2005, 04:36 PM
OK, I've got two JAM's (backup for my boss in case he loses his, no joke, a definite possibility), so I've got the luxury of doing some playing with the spare. These are both 900/1800/1900mhz versions of the JAM bought before the 850mhz version was even available.

I was installing various radios (1.01, 1.05, 1.10, 1.11) seeing which is best. See xda-developers for instructions. I've got T-mobile sims in both JAMs.

I installed 1.10 radio (850mhz version) on the spare JAM, and I liked the speed with which it acquired a signal. Also the signal seemed to hold slightly better in my office, than the 1.05 radio version on my JAM, with both side-by-side.

So I do a little network check, by manually checking for available networks between the two sitting side-by-side. Well the 1.10 radio pops up and gives T-mobile and Cingular as options. And the 1.05 radio pops up with T-mobile and AT&T wireless only. Now I'm pretty sure Cingular in my area is only 850mhz, which would seem to be confirmed by this little test. Of course I can't connect to it, as the sim is T-mobile.

So I go get a Cingular sim from an employee, and pop it in the 1.10 radio JAM and do the manual network check, and Cingular and T-mobile again pop up as options. I pick Cingular and walaa, it connects with about 3 bars. I can make and receive phone calls. The upper right corner of the phone pad says Cingular as well. I then remove the Cingular sim and pop it in my 1.05 radio JAM. I do the manual network check and the only options which appear are AT&T wireless and T-mobile. I can connect to AT&T wireless but have only one bar.

So to recap, I put the Cingular sim in the 1.10 radio JAM (850mhz radio on device which is supposedly only 900/1800/1900mhz) and I can connect to Cingular. I put the Cingular sim in the 1.05 radio JAM (900/1800/1900mhz radio and device) and I can only connect to AT&T wireless not Cingular (it says AT&T wireless in upper right corner of phone pad).

To me, this means that the 900/1800/1900mhz JAM is really 850/900/1800/1900mhz (quad band) but only crippled to tri-band by the radio firmware. Am I all wet here?

edit- my model numbe is PM10A which is supposedly the 900/1800/1900 version.

jackleung
13th April 2005, 09:02 PM
What a great news!!! I am updating my only my radio image to 1.10 (w/ Chinese Dopod 818 1.06 for the OS) and see how it goes.

jehlinger
13th April 2005, 10:10 PM
Jack, careful, check response by a respected and knowledgeable hofo member whtrbt7 here:

http://www.howardforums.com/showthread.php?s=&threadid=612453

Apparently you could damage your GSM radio so that it might malfunction. However, I have seen a few people here who've used the 1.10 radio firmware without adverse results. Anyone have any more feedback?

reo
11th October 2005, 07:50 PM
Hi

i have tested this but unfortunately it is not true, does any know how to convert the 850 MHz JAM to the 900MHz JAM ??

regards
reo