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The Amateur Amateur Fills-In

07/26/2010

By Gary Hoffman, KB0H
ARRL Contributing Editor

My efforts to set up an APRS station (Automatic Packet Reporting System) had come to a standstill. I had installed a program called UI-View32. It was pretty slick, with volumes of data in its Help file, but there were still plenty of parts of it that I didn’t understand. It was time to find an Elmer.

I won’t go into the serendipitous events that led me to contact Rick, W0PC, but I’m very glad that I did. We exchanged a few e-mails, each of which helped me get a little further into UI-View, but Rick thought it would be best if we talked by phone. I agreed.

Before I called Rick, I started writing down the questions that I wanted to ask him. It rapidly became a ludicrously long list, so I figured I’d better stick to questions that would help me get my APRS fill-in station going. They were technical questions, of course, but I did have one philosophical question: What were my responsibilities as the operator of an APRS fill-in station?

After playing a little phone-tag one morning, Rick and I finally managed to get together. Like many Amateur Radio operators, Rick was very friendly and wanted to help. He’d had a lot of experience with APRS in general, and UI-View specifically. And like every other ham, he had some good stories to tell. It was fun, but I was at work and doing this on company time, so I decided to steer the conversation back to my “short” list of questions.

Pöpcørn

Ha! I think Rick and I talked away half the morning. Everything he said was golden. He sat in front of his own UI-View station and went through the entire setup procedure for me. He described and explained each item, and I scribbled it all down as quickly as I could. Question after question was being answered, even before I asked them. Poorly understood concepts were finally beginning to make sense to me.

In my last column, I said that I wanted to set up a digipeater (a digital packet repeater). At that time, I thought I needed a computer and some program like UI-View32. I now know that it’s possible to make a digipeater from just a transceiver and a clever TNC (terminal node controller). Doing it with UI-View is more fun, though, as you can interact with it a lot more easily.

And with Rick’s help, I was able to get UI-View32 to do exactly that.

Now that was cool. I watched my station on aprs.fi and got a warm, fuzzy feeling every time that APRS packets went through my station. I felt connected, part of the great APRS universe.

Bohemian Rhapsody

Okay, that kept me entertained for an afternoon, but soon I was ready to move on to the IGate feature; an IGate is a station that feeds APRS packets into the Internet. At first I wasn’t sure where they went, but it quickly became apparent that there is a complex network of servers moving, sorting, storing and making these data available to whomever wants to look at them. These servers may even send data back to an IGate for local transmission.

Rick explained how to properly configure my station to be an IGate. But before I did so, I had to ask him that philosophical question: What are my responsibilities?

It was sort of a multi-part question. I wanted to know things like: Was I obligated to keep my station running 24 hours a day, 7 days a week? (The answer is no, and I have seen a number of digis and IGates randomly appear and disappear from the map.) Did I need any kind of authority, certification, background check or whatever to send data from my simple station to the APRS servers? (No. I was given a server access code when I registered with UI-View. Registering was necessary in order to get an activation code to make UI-View32 work. It appeared to be a formality, since there was no charge to download the software.)

So, what were my responsibilities?

Common sense and good practice, it appeared. There was no application, no initiation, no secret handshake. There were guidelines, of course, but they seemed reasonable and easy to follow. Other than that, I was on my own.

I went ahead and activated my UI-View32 IGate feature.

My computer didn’t crash. My CPU didn’t get tied up. My DSL line didn’t freeze. My disk didn’t go clackity-clackity-clack. Running my station as an IGate seemed to have very little impact at all. In fact, UI-View32 in general was a fairly benign process on my computer. It was easy to put it in the background, run other things, and practically forget that it was there.

Okay, I had accomplished my goals. I’d set up a digipeater and an IGate. What next?

A lot of things, actually. This had been a fun experiment, but as with many things that I had tried, I was interested in using APRS in emergency communications. Brian, KC0BS, had already let me know that such applications existed and I was curious to see if I might be able to implement some of them.

Stand by Me

The first step was… well, there were so many directions that I could go that I actually took multiple first steps. One was to put together a field digipeater. That was easy enough. All I had to do was duplicate on my laptop everything I’d done on my shack’s computer. Using the field station as an IGate might be problematic, but the other functions would still be useful. That immediately led to another project, which was to install movable, zoomable maps on the system.

Ah. That turned out to be a problem. Many of us have gotten used to browsing various Web sites and finding that they have easily-manipulated Google maps. UI-View32 didn’t have anything that. It was possible to find static maps -- ones that didn’t move or zoom -- and superimpose them on the UI-View screen. But to have features like those on Google Maps it was necessary to buy a commercial product called Precision Mapping Streets and Traveler. Purchasing the mapping software turned out to be a lot harder than installing it, but I finally got past that vexing incident and soon had flexible maps for UI-View.

I now had a fully functional APRS digipeater and IGate. Two, actually. One resided in the more solid, less portable items that rarely leave my shack. The other was in my field equipment, which I actually used during Field Day. Shortly after that, I took it with me on an Independence Day mini-vacation. It worked great.

Smiley-face summary: The more I investigate APRS, the more neat things I find. I’ve sent and received a lot of messages through it. I’ve used it to send email via Winlink. I’ve discovered that there is a lot more APRS traffic around St Louis than I had ever imagined. And I’m very much looking forward to delving into APRS’s uses as an emergency communications tool.

Frowny-face summary: I need to put up an antenna dedicated to my home APRS station, and that means squeezing (grunting, groaning) into the attic crawl-space to run more feedline. Also, the expensive, top-of-the-line internal TNC card that I bought turned out to have come from the bottom-of-the-heap. And why, oh why does my shack’s digipeater suddenly cease functioning at random times during the night? 

So, what’s my final assessment? Positive, I’d say. Any time that you try to connect a computer to a transceiver, you’re going to encounter some maddening difficulties. But if you persevere (and survive), you’ll have a lot of fun with APRS.

Editor’s note: ARRL member Gary Hoffman, KB0H, lives in Florissant, Missouri. He’s been a ham since 1995. Hoffman says his column’s name -- “The Amateur Amateur” -- suggests the explorations of a rank amateur, not those of an experienced or knowledgeable ham. His wife, Nancy, is N0NJ. Hoffman has a ham-related Web page. Readers are invited to contact the author via e-mail.



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