Something less car-ish, but it's actually still related. It's a car phone! Made in the late 80s and for the NMT network. That's an analog 1g network that was what we had before GSM. I remember reading that the nordic countries had the most extensive networks and most amount of mobile phones in the world back in the 80s thanks to Nokia and NMT.
NMT used 450mhz and later 900mhz, the earlier 450mhz gave lots of range when combined with the 15W transmitter that those phones had.
They didn't shut the NMT network down in iceland until the 2010s and it still exists somewhere in siberia!!! That's incredible to me.
Picked up this phone last night, Nokia Mobira Talkman, this one is likely a 900mhz version:
Doesn't specify what Talkman it is, just looks like a 520, this is the designation on the phone:
15 pin serial connector, unsure what it's purpose is.
The phone handset
It uses an RJ45 connector, with it's own color code, I assume it uses serial communication:
No charger though. Needs 12V though and likely several amps.
I'm not sure what I want to do with it, except I want it to work, I want it to live!
There are two ways to go about it, either rip out the guts and replace it with something modern like just make it into a bluetooth set for a modern phone, or the more complicated option. Build an NMT base station simulator, funnily enough there's software for that (and other analog networks) and then connect that to something modern:
http://osmocom-analog.eversberg.eu/
Of course this latter option appeals to me. Just the idea of using that old circuitry and going analog even if only for a short hop to a base station that's a meter away. See what I really want is to install this in my Saab and have it work, ideall with it's own working phone number.
I also want to install in this car it's own 4G modem / router with it's own sim card to make use of the 900mhz antenna on the roof so I can have good wifi out here in the sticks, I lose connection now and then with just my phones built in antenna.
So I got this crazy idea of this phone mounted in the front and in the trunk I have a raspberry pi server or something running osmocom-analog and an asterisk PBX with the required hardware. The sim cards phone number would be the cars phone number and direct to the old phone.
It would be cool, not sure I can make it work. Biggest hurdle is an SDR transceiver, they are not cheap even if they have gone down massively in price. Then I really gotta figure out telephony systems it's all very hard right now because I don't really know how VoLTE and telephony stuff is routed. But give it a few years maybe I'll learn this stuff, maybe I'll loose interest and give up (more likely).
