APRS-IS vs. GPS

Yesterday I put APRS-IS to the test in the mountains on the San Juan Trail, located a few miles way from Ortega Highway 74. In this area there are no digipeaters close enough for RF transmissions, so I tested the SPRINT cellular network to see if I could be tracked in real time (KM6ZPO). I set my ARPS.fi app to send my location every minute whenever cellular data service was available. I was traveling by mountain bike at an average speed of 4.9 MPH over varied terrain, sometimes in canyons.

As you can see in the results …

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APRS: It Works, But It’s Not Reliable

When I first heard about APRS, I had hoped I could use it to replace tracking I already get from my SPOT device. I began my learning curve by testing several APRS apps:

At first, I tried connecting my phones using a purpose-built cable for my Baofeng radio. After trying all of the above software, nothing was working. Using a second radio tuned to the national frequency for APRS (144.390), I could hear my transmissions, but nothing was getting through to the APRS tracking sites like aprs.fi

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First SSTV Image Capture

I finally did it!  I captured this image from the International Space Station using a Yaesu FT-60 radio with a Diamond SRH77CA whip antenna.  I used SSTV for iOS to decode and save the captured audio. 

Check out the video below to see the process in action!

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My First Simplex Contact – In the Middle of the Mojave Desert

Yesterday I went on a little adventure out in the California desert.  I was equipped with a Baofeng UV-5R and a cell phone loaded with APRS.fi software.  Our first destination was the Hole-in-the -Wall  Rings Trail.   Shortly after exiting the 40 highway, I lost cell service, but fortunately before that I was already looking for people transmitting their location via APRS.  I found one!

My contact, K6ORJ, was wise enough to put his simplex calling frequency 146.520 in the comments of his APRS beacon.  I didn’t find him in the campground, but later that day I heard him …

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