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.
- AGWPE link
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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.
- Properties for port 1
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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
- tune aid
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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.
- Audio Level
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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.
- tracker install package
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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.
- MOnitor
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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.
- google map view
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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.
