FJ Cruisers of Northern California

APRS

So I've have started to get heavy into APRS (Automatic Packet Reporting System) after a lull of about 12 years I started to get intrigued by this particular mode of operation again as equipment costs have come down and the fact people are using google maps now to do tracking online in real time.

APRS at a high level can provide real time information such a messaging, bulletins, position tracking, weather information. It integrates the Global Positioning System(GPS) with packet radio which allows for real time tracking. Sure your saying my smart phone can do all this and in most cases your correct, but your cell phone would not be doing this if it wasn't for APRS and packet radio which lead the way to this. Look at it this way in a disaster which network is going to work HAM radio or the cellphone / PSTN networks.

One of the uses of APRS that really intrigues me is incorporating it on trail runs. How cool would it be to have a number of Rigs outfitted with a APRS transmitter and we could see where people are in real time. It would make it easier for the lead rig and the tail-gunner to keep an eye on each other, or see is someone made a wrong turn. If someone breaks down it would show right where they are at so it would be easier to dispatch help to them. When convoying to a trail run you could see where people are on the highway on the way to or from event. This is just scratching the surface of what can be done.

APRS has a fairly low cost barrier. Almost any 2 meter radio can be used. So a older handheld or mobile radio can be picked up used for sometime under 100 bucks. A TNC (Terminal Node Controller) can be picked up for build yourself for 33 bucks like the TinyTrak 3 from Byonics, and most of us already own GPS unites that can output NMEA-183 if not you can get GPS pucks from about 60 bucks.

Or you can get radios that are specifically built this purpose but it can come at a premium cost but you just add GPS and you good to go. Only Yaesu makes a specific GPS module for their radios all the others you need to add your own.

Mobile APRS ready radios

Kenwood TM-700D
Kenwood TM-710D
Yeasu FT-350 (GPS module optional)
Alinco DR-135

Handheld APRS ready radios

Yeasu VX-8r (GPS module optional)
Yeasu VX-8DR (GPS module optional)
Yeasu VX-8GR (GPS module Installed)
Kenwood TH-D7 (there are a few different variations)
Kenwood TH-D72(future)

APRS Trackers - Require a radio and GPS

Byonics TinyTrak 3
Byonics TinyTrak 4 (I'm currently testing this one)
Argent Data Systems - OpenTracker+
Argent Data Systems - Tracker 2

APRS Trackers Radio intergraded just add GPS.

Byonics - MicroTrak RTG
Byonics - MicroTrak AIO GPS is embeded (As easy as it gets)

This list is nowhere near complete just the top models I've researched thus far.

Cables-

Now here is where it gets interesting and potentially expensive. It's very easy to build cables as well as to buy them. Building cables just takes a little understanding of reading the schematics how your going to connect to your radio. Are you using a dedicated data port or do you need to connect into your mic jack and external speaker?

Yeasu for example sells a mini DIN 6 cable with one connector and loose pig tails (CT-39) for around 12 bucks or you can pick up a male to male mini DIN 6pin extension cable at most electronics stores for about 5 bucks and cut it in half and have 2 cables. You can easily tone the cable. Use a continuity meter and test the continuity from pin to pigtale wire. When looking at the connector. make sure the plastic key inside is up. Going clockwise you have pins 6,4,2,1,3,5

The other key to making cables a good soldering iron with a clean pencil tip.

Software-

Most of the software is Windows based, but cheap Windows laptops are easy to come by these days.

The one piece of software I'm looking into is Overland Navagator by Spatical Minds. Craig the developer is a Overlander based in the Northwest and also a HAM operator has been developing this intreguing piece of software. He has added in some basic APRS functions to his 2.0 version and I really hope he continues to add additional features such as APRS messaging in the future.

I will be adding more to this post about operations at a later date.

But if you want to see it work now APRS.fi or openaprs.net are great places to see the realtime use in Northern California and the world. You can find me at KD6WJX-7 (my VX-8r) and KD6WJX-9 ( my FJ)

Replies to This Discussion

Permalink Reply by opg4759 on October 17, 2010 at 4:30pm

most people own dual band HTs or mobiles. You are one of the freaks that doesn't.

But overall yes we will be running 440 for most repeater comms and we will running something in the VHF band for 2 meter for simplex. I'm still working on that proposal. SInce 146.52 is the National calling frequency and it's best not to tie it up. I'm doing research on other groups to see what frequencies they use, but I'm leaning toward 146.550.

I will start another thread on this once I get a little more research done.

Permalink Reply by Sonof40 on October 17, 2010 at 4:38pm

Okay. I am thinking only in terms of trail run use. So 2M simplex would be used for that?

Permalink Reply by gringo on October 22, 2010 at 6:45am

Spent another day trying wiring configs between the radio and tracker II. In certain configs, I can get the tracker to short the transmit signal back to the radio, so there is indeed electrical signals between the 2 devices. I think I may have exhausted all possible combinations of PTT,Audio In/Out, & Ground

I've been away for a week (work), but I'll try to spend some more time this weekend to get it working

Permalink Reply by manoweb on October 17, 2010 at 9:23pm

Software:
Xastir for Linux; among other things, text messaging is extremely convenient. Available in Ubuntu in the software list

Permalink Reply by opg4759 on October 17, 2010 at 9:36pm

I would love to run xstair but I can for the life of me compile maps to work with it. I've tried compiling it for my mac and ubuntu, even their pre-complied virtual machine and the maps will not load.

Permalink Reply by manoweb on October 18, 2010 at 1:39pm

Strange; back in the pre-google maps era, when aerial maps where not free or easily available, I made a little website where I put some maps stolen and re-adapted from a government thing:

http://www.manoweb.com/alesan/mappe/
That stuff was made in the early 2000s. Try to download the jpg and the geo stuff, they work with xastir for sure. Of course those maps are for the Italian territory, but they should be good for a test.