850 MHz versus 900 MHz
 

Eh, I live in New Zealand, if you've heard of that...

If I understand correctly, some cell phone networks use dual frequencies - for example 850 MHz/2100 MHz where the 2100 MHz is used in the built-up city areas and the 850 MHz would be for all other areas. Another frequency pairing is 900 MHz/2100 MHz.

My Blackberry came from Australia, from my company. I use it in New Zealand. The company would usually use the Blackberry on the Australian Optus network. It is a Blackberry 9700 Bold. In New Zealand, I am using a Telecom New Zealand SIM card to operate the phone.

I have a reception problem that I'm not sure whether it is due to the network or the handset. In some places, close to the city centre, there is no reception on my phone.

Telecom NZ think it might be because the Blackberry is trying to use 2100 MHZ/ 900 MHz but their network uses 2100 MHz / 850 MHz.

Vodafone in New Zealand use 2100 MHz / 900 MHz. And Optus in Australia used 2100/900 too.

If my Blackberry is truly unlocked, shouldn't it be able to use both of either of these frequency pairings? Shouldn't it work on either Telecom NZ or Vodafone NZ? If I understand correctly, it is a quad-band phone.

A failure to operate on either of these frequency pairings would limit the ability of the phone to roam right?

Re: 850 MHz versus 900 MHz
 

Forgot to mention, according to the excellent article on this site about unblocked Blackberrys, then my Blackberry is definitely unlocked/unblocked.

Re: 850 MHz versus 900 MHz
 

Please do not double post.
I've answered you here:
http://www.blackberryforums.com/blac...s-900-mhz.html