Portable Devices for Communications via PSK-31?

yipper asks: "Many amateur radio operators are exploring digital communication modes, one of which is a popular mode is called PSK-31. My local emergency communications volunteer group is thinking about using this mode for off-grid emergency setups. The problem is that a computer with a soundcard is more-or-less a requirement, hence my question: we need a lead on small, portable, battery (preferable 12 volt) powered systems which will run Linux or Windows, be easy on batteries, have audio in/out and a serial port. Recommendations can be older technology, as cost is a factor."

Comments

Laptop

[sigwinch]

The obvious solution is an old laptop. 486 and Pentium laptops can be had cheap, and often have built-in sound. Many models have car adapters available to run off 12V.

Various single-board computers would work too, but there's no way they can beat the price of a used laptop.

PCMCIA sound and human power

[andaru]

You could throw a real sound card in the PCMCIA slot in the laptop (even run two sound cards if that helps), but the trade-offs are price and power. The decent audio cards for laptops tend to be expensive (Digigram - $500), and adding a PCMCIA card definately sucks down some juice.

As far as power goes, The Register has this article about a foot powered laptop charger (5 min. of vigorous pumping runs a laptop for 20 min.). They are currently selling a hand operated version for $60. The foot powered one will be $150 when it comes out.

I wouldn't use this as a primary source, but it seems like it might be a very usefull device for the emergency communications volunteer group.

On the other hand, if the aliens are invading and you run down into the basement to your radio bench and find that your 12v batteries have all exploded in some freak accident, 5min. of pumping may be way too much latency for an emergency notification.

I think I remember hearing that in the last test of the amateur radio emergency notification system (all volunteers?) they got the test message spread throughout the country in something like 2min.. That's pretty cool. Keep up the good work.

When they run a test like that, what are the criteria for the message being effectively spread - in other words, how do you know when the test is complete?

Actually, It might be nice for you to post a little explanation of how emergency notification using amateur radio volunteer groups works. I think that a lot of people do not even know there is such a system in place. It would also be enlightening from the point of view of how information can be intentionally propogated acroos a wireless human network.... Just a thought.