APRS at N7TCF

APRS at N7TCF

The N7TCF APRS/Weather beacon began operating in January of 2003.
Tune to the North American APRS frequency of 144.390

APRS in Phoenix, Arizona

This map shows stations and routes in metropolitan Phoenix . Red lines are 'heard direct' stations, Green are digipeated by W7MOT and Yellow digipeated by KD7DR. If the map extended to the west, it would show the W7MOT-3 routes, a mountaintop digipeater. It appears the west side of the city has little activity. My station is in the center and with W7MOT, so strong, I don't digipeat any traffic.

The station was off the air first half 2004, while we tiled the floor. All the cables, desks and hardware had to be disassembled, then reassembled. The tile is done, the station is slowly getting rebuilt. The weather station functioned most of the time though.

Here is the configurations at present:

Software:

UI View32 by Roger Barker, G4IDE. This Windows program is very flexible and full of options, running on Microsoft Windows 95, NT or XP . It operates the TNC in KISS mode or works with the AGWPE software TNC. You import maps as bmp, jpg or gif. Stations are displayed on the map and clicking on the station's icon pops up a window with the station's speed and bearing, beacon text or weather data. The program's feature are too vast for this web page. Roger passed away this summer, 2004, his programs are a fine legacy.

Hardware:

The antenna is a Larsen 5/8 ground-plane, mounted at 20 feet on my roof. The Ringo Ranger II, used until September 2004, was detuning frequently. I haven't noticed any difference in coverage between the two antennas.

Transceiver is an Icom 228A, 2m FM mobile rig. I had to retire the IC-260 as it quit transmitting again (it saw a lot of mobile use.). The newer radio doesn't reset to 145.000 MHz after a power failure! It runs 25 watts or 5 on low power.

The TNC is an old AEA PK-232. UI-View operates the TNC in "kiss-mode", so any TNC could do the job. I bought this one at a swapmeet for $25. I had used an AEA PK-96, which worked very nicely, and an old MFJ 1278, which mangled callsigns and position data.

The TNC feeds data to the weather station computer. UI View is beaconing my weather data, collected by the AAG 1-Wire Weather Station. The weather station and UI-View run on a dual Pentium III-600 with 768MB of ram, the operating system is Windows 2000. This computer also runs a few other UI-View add-ins, MySQL database and the Abyss Web Server. The previous machine was a PII-333 with 256MB of ram. It worked fine, screen updates were sometimes slow, but managed all the tasks fast enough. I found the dual PIII motherboard at a swapmeet of course.

UI-View makes configuring APRS very simple. I strongly recommend it. UI-View can beacon using TCP/IP thru an internet connection without even a radio. It also is server, relaying APRS traffic to my other computers over the home LAN.

The mobile half of my APRS operation is still (going on 2 years) under construction. I have a Tiny Trak beacon controller, Motorola Oncore GPS module and a Radio Shack HTX-202 waiting to be integrated into a beacon. The Tiny Trak is very tiny, along with the Oncore GPS, occupies as much space a Walkman tape player. This is a transmit-only system, needing no TNC or laptop computer. Tiny Trak is having some audio distortion problems, keeping it on the bench.

Your comments, questions or suggestions are welcome. email to N7TCF

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Last edited 10/23/2004