Batboard

Hi all,

I'm having some problems with finding info on a NMT 450 mobile phone i recently got.
On the hand phone unit it says MCR4500XL. On the side of the hetatsink/box it says
Motorola PRM3662D15N-A
F.NO: G0013M907617
MOD.NO.: S01G01

Inside on the controller PCB it says C STORNO A/S 19J711251G1 REV.1 on one of the Eprom's.

It's a 450NMT and it has been used in Sweden.

If someone knows about Service/Operators manuals i would be happy =)
A guide to convert it to 70cm. HAM use would be perfect...

Is it possible it is a mix of the Storno CQM6000unit and the Motorola MC Micro?

/
Erik

All I know about NMT is that it stands for Nordic Mobile Telephone, so I can't help you.. but could you possibly post some pictures of that beast? There aren't too many pics of NMT phones out there in the wild.

If you need an image host, Imageshack works great.

Here's some pictures: I call the PCB with the Storno firmware Eprom "controller-PCB" and the one with the RF-circuits "RF-PCB"

1. Controller PCB


2. Device on controller PCB (Some kind of antenna interface or RF amplifier?)


3. RF-side with shield and holes for access to TP's and adjustments.


4. RF PCB, shields removed


5. Number on RF-PCB.


6. Number on RF-PCB.


7. Number on RF-PCB next to some TestPoints.


8. Label on hand-unit.


9. All parts (yes, I'm missing the battery and the handunit holder...)


The complete unit with battery and handunit-holder http://www.rigpix.com/mobphoneana/motor ... 4500xl.htm

So... i hope someone recognizes something in the pic's. The main purpose of all this is to convert it to operate on the 70cm amateur band.
But it would be nice just to know how this phone works... So if there are some manuals or anything out there, let me know =)

The MHW720A2 module is for the 438 - 470 Mhz. band, so the amp will tune to 440 easily.

The silver 'box' is probably the ceramic filter/duplexer commonly used in that era gear.

Connections are: RX/ANT/TX...either combination, but antenna port usually in center, isolated by each set of ceramic filters for the transmitter and receiver section.

More than likely designed for under 4 watts RF output level, being a full duplex transceiver, probably even less than that.

I'll be willing to bet there is no more than 30dB of isolation between ports with tiny ceramic filters.

Ham usage will require pulling those, rewriting firmware to stop full duplex operation, and writing code to perform offsets of +/- 5 Mhz. with keypad entry.

Too much work for little gain.

Maybe try getting it operational on 440 first, then using it as a link radio perhaps.