Outdoor Adventure USA

APRS was created for realtime tactical coordinating and scene reporting of everything in the area. This includes reporting of location of various assets.

APRS is very applicable for members of this group, especially as it relates to position reporting.

This it just an introduction of APRS and I will put together a little more as I have time.

The APRS setup that I run in my rig is the Kenwood TM-D700 and a Garmin GPSMap. The Kenwood TM-D700 has a built in Terminal Node Controller or TNC that allows for digital communications via audio tones transmitted over the air.

When coupled with a gps receiver it allows for the automatic transmission of position information to other APRS stations in the area. It also allows for text communications between stations for coordinating locations, station capabilities, names, needs or any other type of information you want.

Currently I am working on building an APRS package that I can use on another vehicle that I can monitor in my own.

It consists of a Yaesu FT-7800 and the new Kantronics MT-1200 Digital communicator. It feature s a built-in GPS and the ability to easily add a computer for keyboard to keyboard communications. It features smart beaconing, compressed Mic-e Protocols that make efficient use of the radio frequency. I will add some more information in the coming days.

Awesome...I've been waiting to learn more about APRS and how to set it up in the vehicle...looking forward to reading more about it from you...

Thanks for starting this thread, and including a description of why APRS would be used.
In your next installment, can you include some real world examples of APRS in action? I'm looking forward to learning more.

Imagine driving into a new area, what resources are available to you. APRS beacons may be used to provide repeater information, hamfest information. A mobile station can transmit the frequency it is monitoring, as well as its status. Telemetry beacons are also possible to answer questions like . . . What is the temperature? or battery level? of a remote station, How cold is your refrigerator?

There is a protocol known as APRS Voice alert. This is where individual users enable CTCSS decode capability on their receiver when you find a nearby station you can try contacting them on the APRS digital frequency by encoding a 100 HZ tone that would open squelch on the receiver and allow your voice to pass. Doing so enables the use of your APRS station as both a digital packet station as well as a voice station for local tactical communications.

APRS can also be used for weather reports and even severe weather warnings. APRS has been used for radio direction finding as well. It has been used to contact astronauts in the space shuttle, track runners, scientific balloons, and dog sled races.

When using the APRS system please pay close attention to path settings and beacon rates. APRS is a very popular mode of operation especially in the Southern California Area.

The capacity of the APRS network is nearly always saturated, it is much better in more remote areas, but in congested urban areas please give some thought to the settings you use.

Many new users attempt to create detailed tracks that absolutely kill the network, I have even seen some try a 1 second beacon rate. That is just not good use of the system. It is much better to give a general view of the area's situation, not a detailed position report. You can get a real nice plot of where you are if you use a nice conservative beacon rate.

Other thing to consider are the status display, be sure to indicate how you can be contacted, that is the beauty of APRS. Be aware of the emergency status beacon, that is not something to test. It has the capability to garner a helping hand but it is not something to be abused.

APRS Software and Websites
http://www.googleaprs.com/

http://findu.com/ or centered on SoCal http://aprs.fi/?addr=DM13&mt=m&z=8&timerange=3600

http://www.ui-view.org/

http://www.tapr.org/~kh2z/aprsplus/ For use with older versions of Delorme Street Atlas Version 9 or earlier.

http://aprs.org/

http://wa8lmf.net/aprs/index.htm

http://www.kantronics.com/modems.html

http://www.byonics.com/

http://www.argentdata.com:80/products/aprs.html

OK here are some basic instructions for monitoring the APRS network on the cheap. . .

This software configuration may not be as fully compliant and feature rich as some of the more mainstream software available, it believe it does serve as a good introduction to in the field reception of APRS Data.

This solution will allow you to receive and display APRS data with a minimal cost outlay and no building of interfacing other than an audio cable from your radio speaker output to the line in or microphone input on your computer sound card.

The software can be downloaded for free form the following website http://www.sv2agw.com/downloads/default.htm

This software is for Microsoft Windows Based machines. There are two software packages you will want to download. The first is AGWPE this serves the same function as a piece of hardware known as a Terminal Node Controller or TNC. This serves as a way to convert sounds transmitted over the radio into data useful for data communications.

Go to the website above and download the AGWPE package as indicated in the image below. Install the program and then you will need to create a port. Right Click on the AGWPE icon in your taskbar. then click Properties. click on new port and set up the port like the image below. The important parts are the TNC Type is "soundcard" and the TNC Control Commands are "Single Port." While not necessarily critical you should label the port description as 144.390 as this is the primary frequency for APRS traffic in California. The Comm port will vary on your computer and is only important if you want to go forward and build or purchase an interface. After you set up your properties, the software will prompt you to restart the software when you do so you will notice a new icon next to the AGWPE icon. that is your new virtual TNC.

You will now need to setup the audio cable from your radio to your computer this can be accomplished with a very inexpensive male to male 1/8" stereo audio cable from your radio to your computer. Ideally you want to connect this to your line in input but you may also connect it to the Mic in. In both cases leave the audio control at minimum on your radio until ready to set up the audio levels in the next step.

look at your audio properties for your soundcard recording options ensure the input you have connected your radio to has been selected and not muted. It you used your microphone input ensure the mic boost is not enabled, that may be in the advanced tab or option button for you mic recording input. Tune you radio to 144.39 and turn up your volume on the radio just a little bit.

Right click on the AGWPE icon and select the Soundcard tuning aid Click on sine wave. You want the signal to go about half way between the center line of the top blue field and no more. you can adjust either the audio output on the radio or the slider accessed by the "set volume" button. in any case you do not want to set anything to maximum. Use the combination of audio output from the radio and sound card adjustment sliders to obtain the midway reading on the sine wave display as shown here. This may be a little low, but it is generally better to be a bit low than too high.

Close the dialog box once your levels have been set.

You are now receiving packet data. . . but now you need something to use to display the data. This is where the next Software package you will need.

Again this package is not as full featured and standards compliant as some of the others, but it is an easy to setup to see if APRS is for you.

Again we will go to [url]http://www.sv2agw.com/downloads/default.htm/url]and this time we will download the AGW Tracker installation Package shown here. Install the package and after setup is complete, open the AGWTracker from your start menu. Click on the monitor tab and see if you are receiving packets. If you have followed the directions here you should be.

Here is the cool part, in AGWTracker click on file, open, open google map or open yahoo map you can get a Map that will display the stations you are receiving via the radio. With this setup you will be able to receive messages, bulletins and alerts that may be present on the APRS network. You will however not be able to send anything to network until you buy or build a transmit interface. I hope to cover that aspect in a future post.

Hector:

That's some great info. I am about finished setting up the APRS for my rig and I know that there are at least 2-3 others who will be doing the Parashant who also want to get on board.

What do you think about setting a date in the near future to get together for everyone who wants to set this up, to help fine tune and tweak our systems. With enough lead time, there should be ample opportunities to discuss what is needed and to buy whatever is necessary.

One note about operating the TM-D700 or a couple other APRS-on-Ham (I recall the Alinco DR-120 w/option) rigs is the absence of a absolute time synchronization capability (example - send every 3 minutes after 0:42 seconds into the hour) found on Kantronics standalone units, and somewhat supported on the TinyTrac devices provided by Byonics. This feature allows some event coordinators that use APRS to 'time-slot' the activity so that every sending unit has a clear window. If your only use is for uncoordinated (non-event) situations, the TM-D700 is a nice all-in-one rig for the purpose.

Also, it is fairly easy to access the APRS-IS Servers for information to use in your own software programs. When doing so, its best to use filtered access as the pipe of data for worldwide APRS data will flood you out really fast. There is lots of it shooting around the world.

We just need to coordinate a date, the next few weeks hold a few dates, Sundays may work, or possibly Fridays.

hmfigueroa wrote:We just need to coordinate a date, the next few weeks hold a few dates, Sundays may work, or possibly Fridays.

Hector:

speaking for my self, I have ordered equipment that will not arrive for about 3 weeks (so they say). If we get together before it arrives, I would still like to attend and ask questions and see what other have set up. There are so many questions that need to be answered in order to make sure that it is set up properly.