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October 6th Meeting will not be held
During the last meeting the membership voted to replace the Christmas Dinner with an October picnic. Similarly to the way we replace the second meeting with the Christmas Dinner, the picnic will replace the first meeting. More information will soon be emailed and posted.

Some fun with APRS

I've been using the recent downtime to finally start finishing some of the many projects laying around the shack as well as taking time to go over the manuals for my rigs. I picked up an FT1D a few years back when we started to purchase the Fusion machines but have never had the chance to use many of it's features. One of the things that pulled me towards that radio at the time was the integrated APRS. One project that I've been wanting to hack on for a few years now is integrating a simple text messaging service such as that offered by APRS with a POCSAG pager converted for amature use, something like DAPNET, and eventually tie it in with a VoIP system similar to that offered by the Hamshack Hotline, likely using apt_rpt/ Allstar.

 

While this may sound ambitious to some thankfully most of the pieces are already done in some form by the international amature community, they just need to be tied together and adapted for local use. With this in mind the APRS aspect seems like the best place to start. Unfortunately even though Maryland and the mid-Atlantic states have some of the higest traffic density in the world, almost all of that is east of the Blue Ridge. Access to the larger network from my HT was going to require something more than just a plug and play effort.

 

I started by building a recieve only iGate using a RaspberryPi0W and RTL-SDR dongle using this guide. This approach allowed me to start learning the APRS functions on my HT without worrying about QRM from an improperly configured digi. After a week or so of running that I started to put together a digipeater/ iGate using Direwolf and Xastir as a client. For a radio I'm using a Yaesu FT-2900R with one of the Arduino TNC's by N3YGE and W8RGB that we built as a club project a few years ago. After inital testing with a dummy load I'm currently running the set-up through a chinesium mag-mount on my grill, again to try and keep potential QRM to a minimum as I work out the bugs in my configuration.

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With this simple system in place I again started the process of testing and monitoring which brings me to the point of this post. On Sunday morning I glanced at my Xastir screen and noticed a couple of ballons launching to the west from the Allegheny Front. Looking at the status message showed that they were from the University of Maryland Near Space Balloon Payload Program. According to their website they typically do three or four flights per semester. This is what I initally saw in the shack.

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Pretty cool. I had seen another balloon cross my display the day before but when I went outside to try to eyeball it the sky was uncooperative. Heading outside again on Sunday I couldn't have asked for better conditions and managed to catch a good view of the ballons as they crossed the valley. They're above 40,000' and my lens isn't the best but if you zoom in you can see the payloads.

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This is about where they were in their flight when I saw them outside.

 

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A few more screenshots of their flight as viewed from Xastir.Screenshot from 2020-08-30 09-39-21.png

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and finally a cap from aprs.fi which also shows the chase and recovery vehicles, they could be heard on simplex as they passed through

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This was one of the most interesting expierences I've had so far in the short time since I've been licensed and it didn't take a lot of money or equipment to enjoy. I've since switched to using YAAC as my primary client as the performance is much better for most maps. I'm also looking at APRX for some of my needs. Both Direwolf and APRX are well documented and are so far a pleasure to work with. Direwolf also includes support for APRStt which, once configured, should allow anyone with DTMF to interact with the network.