AmateurRadio.com

I'm not sure how to even begin this post. Yesterday, the final day of NPOTA was such a good day, there was no time to be sad or mourn its end. If NPOTA was the gift of a great big cake to Amateur Radio in 2016 - then December 31, 2016 will go down as the icing on the cake.  It was definitely one of the best days in Amateur Radio that I have ever had. If it wasn't the best, it was right up there in the Top 10 .... maybe the Top 5.

As stated in my earlier post this week, my intention was to come full circle and to end NPOTA as it began, with activations of both the Washington-Rochambeau Trail (TR23) and Morristown National Historical Park (HP28). The day started sunny and a bit cold as I made my way up to Morristown.  I haven't been up there since last May, and since I take all back roads to get there, I was using my TomTom GPS unit to guide me there. About 1/3 of the way there, the TomTom gave up the ghost.  Rebooting and resetting did no good.  The map screen was nothing but a blank, white screen.  Fortunately, I was able to retrace my steps without getting lost.


I set up in the parking lot and set up my 40 Meter Hamstick on the Jeep roof and the magloop right next to the Jeep. I was intending to start out on 40 Meter CW with the tried and proven Hamstick in order to get the 10 minimum QSOs that are needed for a valid activation; and only then switch over to the magloop for 20 Meters, as I really haven't used it enough to be confident in it as a proven performer.

While we were shooting the breeze, we both noticed a group pf people a little bit over in the same parking lot.  They had set up tables and had some drinks and some food that they were enjoying.  One of the women from the group came up to us and asked what we were doing and was my magloop "Some kind of antenna?"  We explained NPOTA and Amateur Radio and that's when she invited us over to join her friends for a warm drink and to explain to all of them what we were doing. It seems they were a group of Norwegian descendants who usually get together, either on Christmas Eve or New Year's Eve to enjoy some food, drink and fellowship outdoors.  They gave Dave and me a hot cup of Glug, which was a mixture of red wine, almonds and raisins.  While we sipped we gave a good talk about Amateur Radio, NPOTA, the ARRL and the National Parks System as well as a few points about Emergency Communications.  They thanked us and we thanked them and then Dave and I headed back to our cars. He left to get back to Morris Plains, and I packed up to head back home to TR23.

About a 1/2 hour later, I arrived at the Frazee House in Scotch Plains, which is right on the Washington - Roachambeau Trail; and it was the same place I activated the Trail from during the NJQRP Skeeter Hunt.  When I activated TR23 last January, I did it from the entrance to the Ashbrook Golf Course.  It was open yesterday and I didn't want to cause any commotion, so I came back to the Frazee House which is only a couple of minutes farther down the road.


This time I decided to use another arrow from my antenna quiver,  I also brought along my Joplin ARC antenna launcher and I got a line over a tree and made use of the PAR ENDFEDZ 40/20/10.


I ran the coax into the Jeep through a crack in the window and got down to business.  I ran off a bunch of QSOs on 40 Meters and was about to switch over to 20 Meters when I noticed out of the corner of my eye that a vehicle had pulled up next to me.  This time, it wasn't another Radio Amateur. This time, it was a member of the Scotch Plains Police Department.  I guess I called some attention to myself, being the only car there, in an otherwise empty place.   I got out of the car and walked a step or two to his rolled down window. I introduced myself and gave the spiel about NPOTA and how Raritan Road is part of the Washington - Rochambeau Trail, which he knew.  What the Officer didn't know was that the trail is part of the National Parks System and he was very surprised by that. Then he told me about how his grandfather was a Ham, that in fact W2KKG was his call sign.  We talked a bit, shook hands and he went on his way; and I returned to the Jeep for 20 Meters.

20 Meter CW proved to be a disappointment. Even with self spotting, I garnered only about 15 QSOs before the activity petered out, way too soon in my opinion.  I sat there, with KX3 calling CQ, debating whether I should pack it in and go home.  It was getting to be around 2:30 PM EST, and I only wanted to be out until around 3:00 PM as I had a previous commitment at 5:00 PM and I had to get ready for that. Wanting to get a least a few more Qs in the log; so I decided that I would give 20 Meter SSB a shot.  With the deep cycle battery, I could boost the KX3's output to 10 Watts. The PAR was up in a tree about 50 feet up or so, so I figured, "What the heck!".  I didn't even bother to spot myself, I just hooked up the microphone and started calling CQ on 14.340 MHz, figuring that what would be, would be.

Much to my surprise, about 60 QSOs later, the pileup ceased.  With 10 Watts, I had worked all up and down the East Coast, across to California and Washington State and even up into Alberta, Canada. In all, there were only 1 or 2 instances where I had to repeat anything. It was pure bliss!

As it started becoming overcast and dusk started settling in, I packed everything up and headed home. I was in another world, walking in rarefied air. NPOTA turned out to be everything it was chalked up to be; and more.  Thanks to Sean, Norm and all the ARRL staff who worked tirelessly behind the scenes to make NPOTA the success that it was. I have never been more proud to be a Life Member of the ARRL.  Friendships that will last a lifetime; and new memories that will last a lifetime are the direct results of NPOTA. It just doesn't get any better than this.

Later, I was talking with my good friend Bob W3BBO on Skype, as we do just about every Saturday evenming,  I had worked him earlier from HP28 and we talked about our QSO a bit more in depth and about the day in general. Bob stated that, in a way, he felt bad for me.  As he tuned around 20 and 40 Meters, it seemed like it was just wall-to-wall NPOTA. He told me that he was sure I should have been at home boosting up my entities worked total. I told him not to feel bad, as not only had I worked a couple new ones via Park to Park QSOs; but there was nowhere in the world that I would have rather been - handing out QSOs as an Activator on the last and best day of NPOTA.

72 de Larry W2LJ
QRP - When you care to send the very least!

I'm not sure how to even begin this post. Yesterday, the final day of NPOTA was such a good day, there was no time to be sad or mourn its end. If NPOTA was the gift of a great big cake to Amateur Radio in 2016 - then December 31, 2016 will go down as the icing on the cake.  It was definitely one of the best days in Amateur Radio that I have ever had. If it wasn't the best, it was right up there in the Top 10 .... maybe the Top 5.

As stated in my earlier post this week, my intention was to come full circle and to end NPOTA as it began, with activations of both the Washington-Rochambeau Trail (TR23) and Morristown National Historical Park (HP28). The day started sunny and a bit cold as I made my way up to Morristown.  I haven't been up there since last May, and since I take all back roads to get there, I was using my TomTom GPS unit to guide me there. About 1/3 of the way there, the TomTom gave up the ghost.  Rebooting and resetting did no good.  The map screen was nothing but a blank, white screen.  Fortunately, I was able to retrace my steps without getting lost.


I set up in the parking lot and set up my 40 Meter Hamstick on the Jeep roof and the magloop right next to the Jeep. I was intending to start out on 40 Meter CW with the tried and proven Hamstick in order to get the 10 minimum QSOs that are needed for a valid activation; and only then switch over to the magloop for 20 Meters, as I really haven't used it enough to be confident in it as a proven performer.

While we were shooting the breeze, we both noticed a group pf people a little bit over in the same parking lot.  They had set up tables and had some drinks and some food that they were enjoying.  One of the women from the group came up to us and asked what we were doing and was my magloop "Some kind of antenna?"  We explained NPOTA and Amateur Radio and that's when she invited us over to join her friends for a warm drink and to explain to all of them what we were doing. It seems they were a group of Norwegian descendants who usually get together, either on Christmas Eve or New Year's Eve to enjoy some food, drink and fellowship outdoors.  They gave Dave and me a hot cup of Glug, which was a mixture of red wine, almonds and raisins.  While we sipped we gave a good talk about Amateur Radio, NPOTA, the ARRL and the National Parks System as well as a few points about Emergency Communications.  They thanked us and we thanked them and then Dave and I headed back to our cars. He left to get back to Morris Plains, and I packed up to head back home to TR23.

About a 1/2 hour later, I arrived at the Frazee House in Scotch Plains, which is right on the Washington - Roachambeau Trail; and it was the same place I activated the Trail from during the NJQRP Skeeter Hunt.  When I activated TR23 last January, I did it from the entrance to the Ashbrook Golf Course.  It was open yesterday and I didn't want to cause any commotion, so I came back to the Frazee House which is only a couple of minutes farther down the road.


This time I decided to use another arrow from my antenna quiver,  I also brought along my Joplin ARC antenna launcher and I got a line over a tree and made use of the PAR ENDFEDZ 40/20/10.


I ran the coax into the Jeep through a crack in the window and got down to business.  I ran off a bunch of QSOs on 40 Meters and was about to switch over to 20 Meters when I noticed out of the corner of my eye that a vehicle had pulled up next to me.  This time, it wasn't another Radio Amateur. This time, it was a member of the Scotch Plains Police Department.  I guess I called some attention to myself, being the only car there, in an otherwise empty place.   I got out of the car and walked a step or two to his rolled down window. I introduced myself and gave the spiel about NPOTA and how Raritan Road is part of the Washington - Rochambeau Trail, which he knew.  What the Officer didn't know was that the trail is part of the National Parks System and he was very surprised by that. Then he told me about how his grandfather was a Ham, that in fact W2KKG was his call sign.  We talked a bit, shook hands and he went on his way; and I returned to the Jeep for 20 Meters.

20 Meter CW proved to be a disappointment. Even with self spotting, I garnered only about 15 QSOs before the activity petered out, way too soon in my opinion.  I sat there, with KX3 calling CQ, debating whether I should pack it in and go home.  It was getting to be around 2:30 PM EST, and I only wanted to be out until around 3:00 PM as I had a previous commitment at 5:00 PM and I had to get ready for that. Wanting to get a least a few more Qs in the log; so I decided that I would give 20 Meter SSB a shot.  With the deep cycle battery, I could boost the KX3's output to 10 Watts. The PAR was up in a tree about 50 feet up or so, so I figured, "What the heck!".  I didn't even bother to spot myself, I just hooked up the microphone and started calling CQ on 14.340 MHz, figuring that what would be, would be.

Much to my surprise, about 60 QSOs later, the pileup ceased.  With 10 Watts, I had worked all up and down the East Coast, across to California and Washington State and even up into Alberta, Canada. In all, there were only 1 or 2 instances where I had to repeat anything. It was pure bliss!

As it started becoming overcast and dusk started settling in, I packed everything up and headed home. I was in another world, walking in rarefied air. NPOTA turned out to be everything it was chalked up to be; and more.  Thanks to Sean, Norm and all the ARRL staff who worked tirelessly behind the scenes to make NPOTA the success that it was. I have never been more proud to be a Life Member of the ARRL.  Friendships that will last a lifetime; and new memories that will last a lifetime are the direct results of NPOTA. It just doesn't get any better than this.

Later, I was talking with my good friend Bob W3BBO on Skype, as we do just about every Saturday evenming,  I had worked him earlier from HP28 and we talked about our QSO a bit more in depth and about the day in general. Bob stated that, in a way, he felt bad for me.  As he tuned around 20 and 40 Meters, it seemed like it was just wall-to-wall NPOTA. He told me that he was sure I should have been at home boosting up my entities worked total. I told him not to feel bad, as not only had I worked a couple new ones via Park to Park QSOs; but there was nowhere in the world that I would have rather been - handing out QSOs as an Activator on the last and best day of NPOTA.

72 de Larry W2LJ
QRP - When you care to send the very least!

"Going cold turkey" - a phrase familiar to some - unfamiliar to others. Perhaps many of my readers from outside the US have never heard of this American slang term before.  It means to break a habit ...... by stopping.  If you happen to smoke and decide to stop "cold turkey", that means stopping. Period. No gradually smoking less and less until you quit. Nope, you throw away your last pack of cigarettes into the trash can and never smoke again.

I smoked for a very brief period of time (maybe 1/2 a year) when I was in college and to this day, I'll enjoy a cigar at a wedding, if they're being offered; but I never smoked to the point where it became a habit. I can imagine though, for a hard core chain smoker, the thought of going "cold turkey" probably produces cold sweats and chills down the spine.

Thanks to the ARRL, many of us have become addicted to National Parks on the Air.  I say that in a teasing and friendly manner.  But the fact remains that for the past 12 months we have really enjoyed chasing and activating the over 400 National Park System entities.


A lot of folks went in whole hog and seemed to make it their mission to activate as many entities as possible.  Some made it a family affair, taking their spouses and children on a tour of the USA. Some seemed to take a sabbatical from work in order to satisfy their craving.  Some slept in cars, hopping from site to site, alternately activating and then hunting for a spot with WiFi so they could upload their logs to Logbook of the World.  A lot were like me, activating sites that were relatively close to home when chores and family commitments allowed some of that seemingly rare  commodity - free time.  One thing seemed certain, though, whether you were a hard core NPOTA'er or just an occasional dabbler ...... everyone who got involved had a good time.

So it is with mixed emotions that I anticipate the end of NPOTA 2016.  I will always have fond memories of my activations, and of how I incorporated NPOTA into the 2016 NJQRP Skeeter Hunt, and of the many hours I spent behind the key (and microphone) as a chaser. I think I spent more time behind the microphone this year than in all my 38 years of Amateur Radio combined.

I will also fondly remember the friendships that have formed with many activators and fellow chasers on the air and through the NPOTA page on Facebook.  Call signs have become names and faces instead of just random letter/number combinations.  In a few instances, Hams that I have known for years and have only worked via Morse Code have now become familiar voices! And when was the last time a fellow Ham gave you cookies or a pizza for working them? Chalk up those innovative ideas for fellowship to NPOTA!

For many, NPOTA became an opportunity for us to rethink how we thought about Amateur Radio. A lot of us had to shed all previous notions and start thinking outside the box. For many it was the first time they ever operated outside the home Shack other than Field Day. NPOTA became a fantastic opportunity to learn about what works and what doesn't.  Many of us became more in tune with our equipment, using it in ways we never had before, expanding our capabilities and experiences. It was an opportunity for many to build and experiment with new antenna systems, new power systems, new ways of doing things that were previously taken for granted. For many of us, it also became a school for learning (real fast!) how to improvise when piece of equipment was forgotten; or how to make quick (and sometimes not so pretty) repairs when something would break or malfunction.  Through it all, we became better Amateur Radio Operators because of it; and there's no amount of money you can place on that.

It will be very hard for all NPOTA'ers when 23:59:59 UTC rolls around on December 31st and it's all gone; and we're all going "cold turkey". As far as this particular event is concerned, microphones and keys will go silent and we'll only have the sweet memories of the past 12 months to comfort us. It will seem strange not to turn on the rig and twiddle the dial looking for that new entity to work - looking for familiar call signs that we could count on to be activating some new place of historical significance.

So many thanks go out.  To Sean Kutzko KX9X and Norm Fusaro W3IZ from the League, who did a magnificent job tending and managing the NPOTA program. To the ARRL for sponsoring the event and making the resources available that  are necessary to run something of this magnitude.  Web space and server space don't grow on trees, so the next time you're ready to grouse about "What does the ARRL do for me?" ....... well, here's a good example.


Thanks to the many before mentioned activators, who provided me with so many moments of fun as well as so many moments of anticipation, and yes, even some moments of frustration.  Many thanks to the chasers who worked me (and will work me tomorrow during my two, final activations). Without all you fine folks, this NPOTA concept would have been just that - a concept.  You all breathed life into what may well go down in history as the most fondly remembered activity the ARRL ever sponsored.

Lastly, so many thanks to the National Park System and its employees. You have been the most kind and gracious hosts to all of us these past twelve months. You not only were knowledgeable and competent guides, you also became good friends.  We are in your debt for your generous hospitality.

72 de W2LJ
QRP - When you care to send the very least!

"Going cold turkey" - a phrase familiar to some - unfamiliar to others. Perhaps many of my readers from outside the US have never heard of this American slang term before.  It means to break a habit ...... by stopping.  If you happen to smoke and decide to stop "cold turkey", that means stopping. Period. No gradually smoking less and less until you quit. Nope, you throw away your last pack of cigarettes into the trash can and never smoke again.

I smoked for a very brief period of time (maybe 1/2 a year) when I was in college and to this day, I'll enjoy a cigar at a wedding, if they're being offered; but I never smoked to the point where it became a habit. I can imagine though, for a hard core chain smoker, the thought of going "cold turkey" probably produces cold sweats and chills down the spine.

Thanks to the ARRL, many of us have become addicted to National Parks on the Air.  I say that in a teasing and friendly manner.  But the fact remains that for the past 12 months we have really enjoyed chasing and activating the over 400 National Park System entities.


A lot of folks went in whole hog and seemed to make it their mission to activate as many entities as possible.  Some made it a family affair, taking their spouses and children on a tour of the USA. Some seemed to take a sabbatical from work in order to satisfy their craving.  Some slept in cars, hopping from site to site, alternately activating and then hunting for a spot with WiFi so they could upload their logs to Logbook of the World.  A lot were like me, activating sites that were relatively close to home when chores and family commitments allowed some of that seemingly rare  commodity - free time.  One thing seemed certain, though, whether you were a hard core NPOTA'er or just an occasional dabbler ...... everyone who got involved had a good time.

So it is with mixed emotions that I anticipate the end of NPOTA 2016.  I will always have fond memories of my activations, and of how I incorporated NPOTA into the 2016 NJQRP Skeeter Hunt, and of the many hours I spent behind the key (and microphone) as a chaser. I think I spent more time behind the microphone this year than in all my 38 years of Amateur Radio combined.

I will also fondly remember the friendships that have formed with many activators and fellow chasers on the air and through the NPOTA page on Facebook.  Call signs have become names and faces instead of just random letter/number combinations.  In a few instances, Hams that I have known for years and have only worked via Morse Code have now become familiar voices! And when was the last time a fellow Ham gave you cookies or a pizza for working them? Chalk up those innovative ideas for fellowship to NPOTA!

For many, NPOTA became an opportunity for us to rethink how we thought about Amateur Radio. A lot of us had to shed all previous notions and start thinking outside the box. For many it was the first time they ever operated outside the home Shack other than Field Day. NPOTA became a fantastic opportunity to learn about what works and what doesn't.  Many of us became more in tune with our equipment, using it in ways we never had before, expanding our capabilities and experiences. It was an opportunity for many to build and experiment with new antenna systems, new power systems, new ways of doing things that were previously taken for granted. For many of us, it also became a school for learning (real fast!) how to improvise when piece of equipment was forgotten; or how to make quick (and sometimes not so pretty) repairs when something would break or malfunction.  Through it all, we became better Amateur Radio Operators because of it; and there's no amount of money you can place on that.

It will be very hard for all NPOTA'ers when 23:59:59 UTC rolls around on December 31st and it's all gone; and we're all going "cold turkey". As far as this particular event is concerned, microphones and keys will go silent and we'll only have the sweet memories of the past 12 months to comfort us. It will seem strange not to turn on the rig and twiddle the dial looking for that new entity to work - looking for familiar call signs that we could count on to be activating some new place of historical significance.

So many thanks go out.  To Sean Kutzko KX9X and Norm Fusaro W3IZ from the League, who did a magnificent job tending and managing the NPOTA program. To the ARRL for sponsoring the event and making the resources available that  are necessary to run something of this magnitude.  Web space and server space don't grow on trees, so the next time you're ready to grouse about "What does the ARRL do for me?" ....... well, here's a good example.


Thanks to the many before mentioned activators, who provided me with so many moments of fun as well as so many moments of anticipation, and yes, even some moments of frustration.  Many thanks to the chasers who worked me (and will work me tomorrow during my two, final activations). Without all you fine folks, this NPOTA concept would have been just that - a concept.  You all breathed life into what may well go down in history as the most fondly remembered activity the ARRL ever sponsored.

Lastly, so many thanks to the National Park System and its employees. You have been the most kind and gracious hosts to all of us these past twelve months. You not only were knowledgeable and competent guides, you also became good friends.  We are in your debt for your generous hospitality.

72 de W2LJ
QRP - When you care to send the very least!

Due to the restrictions on airborne amateur radio operation in the UK High Altitude Balloon (HAB) enthusiasts have been forced to utilise licence exempt low power devices in novel ways to make radio trackers for their payloads. I have written plenty on this blog about my HAB tracking, the UKHAS distributed listener network and my own flights.

Until recently the preferred method was to use RTTY transmissions, however the advent of the IoT (Internet Of Things) has seen manufacturers of radio modules develop devices to increase both the range and reliability of communication between 'connected' embedded devices.

One such development are LoRa devices, primarily for devices to connect to a global wide-area network LoRaWAN, more information can be found at the LoRa Alliance in addition there are some open hobbyist networks such as The Things Network using these devices.

Using chirp spread-spectrum modulation these LoRa devices are marketed as being capable of robust, interference and fade resistant communication over longer distances and higher data rates.

The UK HAB community has begun experimenting with these devices and one of their keen proponents is Dave Akerman (M0RPI). Dave has developed both payload software for the "Pi In The Sky" PITS tracker along with Anthony Stirk (M0UPU) and gateway software in collaboration with Robert Harrison M0RJX. The 'gateway' is the necessary receiver element to upload the data to the tracking system. (all software is on the PITS Github page)

Dave gave an informative presentation on LoRa at the UKHAS 2016 Conference which is now available online (starts around 3 minutes in)


I had intended to fly a LoRa transmitter on my 2015 Hamfest balloon but it stopped working at the eleventh hour and hadn't done anything else with LoRa till recently.

Spurred on by the conference presentation and the fact more and more flights are carrying LoRa I invested in one of the Raspberry Pi expansion boards sold by Uputronics and built up another prototype tracker with a working LoRa module.

I have done talks at various radio clubs and societies and demonstrated it working but hadn't actually received a 'real flight' as opportunities have been scarce due to the weather. However in the few weeks I have tracked a couple of flights receiving both telemetry and image data, getting a couple of complete images from the imaginatively named 'SPACE' flight.


Dave Akerman also flew a flight experimenting with multiple payloads using Time-division multiplexing (TDM). It had 10 small of "AVRLoRaNut" trackers (of Anthony M0UPU's design) all set to the same frequency (434.450MHz) and same transmission mode. The trackers took turns to transmit, with each one allocated a particular transmission slot in a 20-second cycle. The cycle was GPS-timed but, if any tracker lost GPS lock then it derived timing from the transmissions from the other trackers (the LoRa devices are also receivers) All 10 trackers were suspended from the same balloon. This was in preparation for the 'Operation Outward' re-enactment next year (Steve Randall gave a presentation on it in the above conference video starts 1 hour 16 mins in)

I successfully received telemetry despite the flight not being local and constantly heading away from me as can be seen in the screen shots.


Always a busy man Dave also flew a flight with an experimental camera setup. The SSDV images this time came from a Nikon compact camera, connected to the Raspberry Pi via USB, and using gphoto2 software to take and transfer images to the Pi where they were stored, resized and converted to SSDV format for transmission. These were large images with a high quality SSDV setting so lots of packets per image, approx 1400 per image in testing. 

This flight was using a 868MHz LoRa device, rather than the usual 434MHz due to the IR2030 restriction on bandwidth and duty cycle. Dave was using his Turbo-X or Mode 4 setting which is as fast as LoRa will go within IR2030 bandwidth restrictions (approx 8 packets / 2k bytes per second)

I hastily ordered a 868MHz device and soldered it in the spare slot on my gateway and built a collinear for 868MHz similar to the one I built for ADB-S reception (see video here).


You can see it lashed up just below the dual-band collinear - not ideal mounting and it wasn't tested in anyway, built blind!  The less than optimal setup at UHF, the insane data rate and the distance (>100miles) were going to make reception difficult, so I was pleased I did manage to receive telemetry and image packets.

 
Most of the current LoRa development in the HAB community has tended to be on the Raspberry Pi due to the use with SSDV and the easy availability of cameras and ready built kit. LoRa is of course available on the Arduino platform and I had purchased a couple of 'Dragino' shields (pictured below) with a LoRa device on.


Dave has done some work on a AVR tracker software and a simple Arduino 'Serial' LoRa receiver. The receiver connects to a host PC appearing as a serial port and by running some gateway software the receiver can be configured via the serial link and received data is sent back to the gateway to be uploaded to the Habitat tracking system and SSDV system - the software can be seen here during the 'Operation Outward' test flight.


This gateway software is written in Pascal using Delphi and is not as functional as the Raspberry Pi Gateway software. Dave has made the source code available but I am not au fait at all with Delphi however I installed the free development IDE and intended to get in and make modifications but it seems to require a non-free(?) library for the serial comms so ditched the idea.

Instead I have spent the last few days developing a C# .NET version using Microsoft Visual Studio (the community version is free) and also have been modifying the Arduino code in the receiver to add functionality, such as storing the SSDV images locally.

It is still a work in progress but I have made a video showing the current state


Anyway as Cilla Black would say it's been a Lorra Lorra Laughs!

Due to the restrictions on airborne amateur radio operation in the UK High Altitude Balloon (HAB) enthusiasts have been forced to utilise licence exempt low power devices in novel ways to make radio trackers for their payloads. I have written plenty on this blog about my HAB tracking, the UKHAS distributed listener network and my own flights.

Until recently the preferred method was to use RTTY transmissions, however the advent of the IoT (Internet Of Things) has seen manufacturers of radio modules develop devices to increase both the range and reliability of communication between 'connected' embedded devices.

One such development are LoRa devices, primarily for devices to connect to a global wide-area network LoRaWAN, more information can be found at the LoRa Alliance in addition there are some open hobbyist networks such as The Things Network using these devices.

Using chirp spread-spectrum modulation these LoRa devices are marketed as being capable of robust, interference and fade resistant communication over longer distances and higher data rates.

The UK HAB community has begun experimenting with these devices and one of their keen proponents is Dave Akerman (M0RPI). Dave has developed both payload software for the "Pi In The Sky" PITS tracker along with Anthony Stirk (M0UPU) and gateway software in collaboration with Robert Harrison M0RJX. The 'gateway' is the necessary receiver element to upload the data to the tracking system. (all software is on the PITS Github page)

Dave gave an informative presentation on LoRa at the UKHAS 2016 Conference which is now available online (starts around 3 minutes in)


I had intended to fly a LoRa transmitter on my 2015 Hamfest balloon but it stopped working at the eleventh hour and hadn't done anything else with LoRa till recently.

Spurred on by the conference presentation and the fact more and more flights are carrying LoRa I invested in one of the Raspberry Pi expansion boards sold by Uputronics and built up another prototype tracker with a working LoRa module.

I have done talks at various radio clubs and societies and demonstrated it working but hadn't actually received a 'real flight' as opportunities have been scarce due to the weather. However in the few weeks I have tracked a couple of flights receiving both telemetry and image data, getting a couple of complete images from the imaginatively named 'SPACE' flight.


Dave Akerman also flew a flight experimenting with multiple payloads using Time-division multiplexing (TDM). It had 10 small of "AVRLoRaNut" trackers (of Anthony M0UPU's design) all set to the same frequency (434.450MHz) and same transmission mode. The trackers took turns to transmit, with each one allocated a particular transmission slot in a 20-second cycle. The cycle was GPS-timed but, if any tracker lost GPS lock then it derived timing from the transmissions from the other trackers (the LoRa devices are also receivers) All 10 trackers were suspended from the same balloon. This was in preparation for the 'Operation Outward' re-enactment next year (Steve Randall gave a presentation on it in the above conference video starts 1 hour 16 mins in)

I successfully received telemetry despite the flight not being local and constantly heading away from me as can be seen in the screen shots.


Always a busy man Dave also flew a flight with an experimental camera setup. The SSDV images this time came from a Nikon compact camera, connected to the Raspberry Pi via USB, and using gphoto2 software to take and transfer images to the Pi where they were stored, resized and converted to SSDV format for transmission. These were large images with a high quality SSDV setting so lots of packets per image, approx 1400 per image in testing. 

This flight was using a 868MHz LoRa device, rather than the usual 434MHz due to the IR2030 restriction on bandwidth and duty cycle. Dave was using his Turbo-X or Mode 4 setting which is as fast as LoRa will go within IR2030 bandwidth restrictions (approx 8 packets / 2k bytes per second)

I hastily ordered a 868MHz device and soldered it in the spare slot on my gateway and built a collinear for 868MHz similar to the one I built for ADB-S reception (see video here).


You can see it lashed up just below the dual-band collinear - not ideal mounting and it wasn't tested in anyway, built blind!  The less than optimal setup at UHF, the insane data rate and the distance (>100miles) were going to make reception difficult, so I was pleased I did manage to receive telemetry and image packets.

 
Most of the current LoRa development in the HAB community has tended to be on the Raspberry Pi due to the use with SSDV and the easy availability of cameras and ready built kit. LoRa is of course available on the Arduino platform and I had purchased a couple of 'Dragino' shields (pictured below) with a LoRa device on.


Dave has done some work on a AVR tracker software and a simple Arduino 'Serial' LoRa receiver. The receiver connects to a host PC appearing as a serial port and by running some gateway software the receiver can be configured via the serial link and received data is sent back to the gateway to be uploaded to the Habitat tracking system and SSDV system - the software can be seen here during the 'Operation Outward' test flight.


This gateway software is written in Pascal using Delphi and is not as functional as the Raspberry Pi Gateway software. Dave has made the source code available but I am not au fait at all with Delphi however I installed the free development IDE and intended to get in and make modifications but it seems to require a non-free(?) library for the serial comms so ditched the idea.

Instead I have spent the last few days developing a C# .NET version using Microsoft Visual Studio (the community version is free) and also have been modifying the Arduino code in the receiver to add functionality, such as storing the SSDV images locally.

It is still a work in progress but I have made a video showing the current state


Anyway as Cilla Black would say it's been a Lorra Lorra Laughs!