Radio Preppers

General Category => Digital Modes => Topic started by: N1KTJ on April 28, 2016, 03:21:45 PM

Title: HF APRS
Post by: N1KTJ on April 28, 2016, 03:21:45 PM
Am surprised there is not more talk of messaging via the message mode of APRS.  You can even send a text via a gateway that resides on APRS to do just that.  Combine that with some HF capabilities and you can communicate anywhere in any conditions.

The latest I am looking at is called ROBUST  PACKET to get through when all other paths are too noisy.

Title: Re: HF APRS
Post by: STN on October 07, 2016, 11:49:02 PM
HFAPRS is actually a brilliant idea. PSKMail already has this. WolphiLink is working (very slowly) on an Android version. For apple users, tgere is APRSPro!

I'm already testing the Wolphi version, but it's a long way away.

Title: Re: HF APRS
Post by: gil on October 08, 2016, 06:41:59 AM
I don't think much people know about APRS, especially on HF. To me APRS is a way to send your position from a GPS equipped VHF/UHF radio to another. I had no idea it could be used to send a message. I always considered APRS utterly useless to me... And maybe it is, to me. I had a brief look at the article and have no idea what they are talking about. I think the author assumes the reader already knows what it is and does. I do not see how it could be useful in a prepping context, but I'm all ears.. I am slow at getting on the digital bandwagon simply because it implies a couple more pieces of gear in a situation where simpler is better. If it wasn't for winlink I would never buy an interface.. Morse code is my digital mode and my decoder is between my ears, no batteries needed ;-) I'll get to it again eventually, but will not rely on digital modes...

Title: Re: HF APRS
Post by: Quietguy on October 08, 2016, 06:58:14 PM
APRS is a convenient protocol to send any kind of short data packets - short "text" messages, battery/system voltage, ambient temperature, equipment temperature, river/lake levels... a custom interface can be built which sends alarm system status of a remote site.  It will tell you when the tripwire on the trail leading to your cabin is tripped and it will monitor the status of your gates.  All it takes is a little DIY and you can get away from the range limitations of unlicensed wireless devices.

Backpack survivalism is not in the cards for some of us, so a little extra infrastructure can be worth the time and effort.  It becomes a force multiplier for those of us who, because of age or infirmity, can no longer throw the ruck over the shoulders and march off into the sunset.  EMDV.  (Everyone's Mileage Does Vary)

Title: Re: HF APRS
Post by: gil on October 08, 2016, 07:18:06 PM
Interesting.. Especially if the message can be stored upon reception and read later. It does seem a bit complicated, but for someone bugged-in, I can see the utility now.. This is why it's good to read about such things here! Glad I learned something new about my hobby today :-) I suspect the Arduino board can be of some use for interfacing alarms and radios here?

BTW backpack survivalism isn't in the cards for most anyone anyway. Not for long in any case.. Most people who consider it an option have never tried anything remotely close to it and have no idea how hard it is, especially finding enough food.. Most bug out bags are way too heavy and their owners not in shape.. Better have a large family or very good friends to settle in with..

Title: Re: HF APRS
Post by: Quietguy on October 08, 2016, 08:58:40 PM
Interesting.. Especially if the message can be stored upon reception and read later.

Yes - it's just data; APRS allows a limited amount of free-form text.  The radio/TNC feeds what it hears into a computer as ASCII text and what you do with it on the computer is up to you and the program you run.  People are using Raspberry Pis and RTL-SDRs to process APRS data using Linux software.  I have been involved in an application where we used a 2m radio, Kantronics TNC and Windows laptop to process specific APRS data and upload it to a web server for plotting.  The laptop sits there 24/7 running a cron job where it throws away the stuff we don't want and uploads the stuff we do want to a hosted server.  PHP scripts on the web server process the data for plotting on demand.  We already had the equipment but I'm thinking about replacing it with a RTL-SDR/RPi combo just to free up the "real" radio, TNC and laptop for other use.  It seems kind of a waste to keep a perfectly good 2m mobile sitting there doing 24/7 receiver duty.

Lots of potential, but some creative DIY interfacing may be required for non-standard applications.