I have an SBD9602 (old school) modem. Actually I have two of them!
My system is a Raspberry Pi B+ with a 802.11n USB Wifi dongle and the SBD9602 based unit. That looks like a serial port to Linux. I run a Raspbian Jessie kernel on the Pi and it is setup to look like a normal Wifi access point. If you connect ethernet to it, then it behaves just like a home router but with very lax security.
My software is in Python and wraps up a webserver and modem driver. The webserver serves up a spot page and a modem status page. You connect to it via your phone’s wifi.
When I use it I arrive on a summit and plug the USB modem into the Pi, place the modem antenna skywards and power it up. It takes 3mins for the 3F capacitor in modem PSU to charge and another minute to gain sync on the satellite network. During this time Linux boots and faffs about waiting for ethernet then starts the webserver. I setup the antennas for HF during this period and by the time I’ve sat down with 817 and found a frequency, it’s already to go. Access the webpage from the phone, type in the details, click spot and kiss 16p goodbye. 25secs later the spot appears on SOTAwatch.
£191 SBD9602 system
£28 Pi B+
£6 6-28V psu
£4 wifi dongle
£239 plus 30hours or so writing and perfecting the software on the Pi and at the SMS server in the US. And about £30 in Iridium time and costs to get it working.
I was most annoyed it wasn’t not working when I was in Dumfries/Stranraer this last week. Turned out to be Firefox on my phone, my software was working fine when I used an old Blackberry Curve to access it.
Huge amounts of fun to develop, but it’s a bit boring now as it simply, power on, pay money, place spot.