That is a great idea, but I was actually hoping to have her with me. But I was looking at the commercial AVL systems which if I'm not mistaken, a lot of are based on MDC. I'll check out APRS some more. Thanks
I have been looking for a new TNC for APRS as I recently purchased an FT-8900R for my car (10,6,2 meters and 70 cm). Since the FT-8900 is a dual receiver/transmitter unit with cross-band capabilities and can take a 1200 or 9600 baud connection to the radio I went looking. Here is something I found that is interesting;http://www.crosscountrywireless.net/aprs_tnc.htm
I like it because it can also be used as an APRS digipeater, APRS node, Packet modem, etc... You can stick little text messages on the APRS packet like S.O.S. or even things that may have a personal meaning to someone who may be tracking your progress in the back country. Digital modes can work in much poorer signal conditions than voice as you only need to squeeze through a hundred milliseconds or so of data for a packet.
If you have a general class license you could always use some of the HF digital modes like ALE where there is near worldwide coverage through pilot stations (there are like a half-dozen in the US). This at least uses a standardized set of frequencies on almost every HF band that you could load into a radio and use the free software on the hflink web site to do digital data.http://hflink.net/
There are even some HF digital modes that are intended for very low power level operations but it would be hit or miss to establish a contact. You could also go the PACTOR route and connect through some of the maritime nets that operate in the ham band.
Just think outside of the box, there are so many different modes that we have available to us that it would seldom be necessary to do something like a MARS/CAP mod on a VHF radio and then to think that you have your bases covered.
BTW, in the past I was a paramedic and had called in a Lifeflight helicopter a few times before. They had the ability to come up on just about any frequency while onboard the helicopter. Usually our dispatcher would tell them to come up on 155.055 or something similar and while they were 15-20 miles out we would start to coordinate details on a landing zone. I know that they would have the ability to get onto the ham bands if need be.
If you are really concerned about getting into a serious problem while backcountry you should consider one of those new version ELT's that operate in the UHF spectrum. They are monitored by satellite, aircraft, etc.. and can be tracked down by rescue services. There are even some HF type versions for rescuing skiers who have been trapped by avalanches (penetrates the snowpack).
Having seen the photographs of Mr. Fawcett's aircraft it was no wonder that they never heard his ELT. That aircraft was tore into tiny little pieces across the hillside. Since he did not survive the crash he never had a chance to activate the wristwatch ELT that he frequently wore.
Tisha Hayes, AA4HA