High Altitude Balloon Tracker WSPR APRS

As the sun rises on the West Coast, AG6NS-11 nears Solar Noon two-thirds of the way through it's Transatlantic Crossing at the start of it's 4th day of being a High Altitude Balloon.

The 20 meter WSPR transmission, only being powered by a small solar panel, is being heard from Alaska to Australia!

Plans were made to launch the first RP2040 based 20 meter WSPR beacon transmitter for Saturday morning 8am on April 22nd 2023. The test flight of Kazu's latest design given the call sign designation AG6NS-11. We had chosen the primary launch site in Hayward California where we had previously done our first latex floater launch

Freshly flashed board, it blinks, ship it! Additional components to come for APRS.

• 07:59 soldering antenna to balloon payload (in the trunk)
• 08:09 positioning for launch in the park
• 08:10 power test with solar panel angled directly to sun
• 08:11 un-spooling/de-tangling antenna wires
• 08:12 initial float of balloon
• 08:14 verifying WSPR signal transmission
• 08:17 launch attempt 1
• 08:20 reposition for launch
• 08:21 launch attempt 2
• 08:23 launch attempt 3 (success)
• 09:12 first WSPR spot reported from CM87wp (S.W. of launch)
• 11:36 new grid square spot CM86xw (off the coast of Santa Cruz)
• 16:22 last spot for the day CM95ws (between Monterey & Bakersfield)
• 21:25-21:46 moonlight ping? DM05co

Tracking the first day of flight via APRS.fi relayed from LU7AA.org and WSPRnet.org

K6RGG listening to whispers, tuned to the 20 meter band.

Kazu started assembly of boards and was preparing for a launch. There was just one critical component missing, a GNSS/GPS receiver. I had a stash of these still on hand from W6MRR's AVR based boards and we made plans for a rendezvous at the return of the Electronics Flea Market

This event is a long standing Silicon Valley tradition that has mostly been on hiatus for the last several years. If you've never found yourself in an empty parking lot well before dawn, as HAMs from all over come out of the woodwork to bond over coffee, donuts and the age old question of how many more of these things that I don't particularly need (right now) do I actually absolutely have to have? Kazu debated this with me for a few in our particular case of modules. I think they have 5 or 6 boards to build, and settled on 7 or 8 modules as a good number to have on hand.

This is the log jam of sellers still being processed at dawn as things started to get going around 6am in the main lot. Some people were already there at 4am, ahhhem, so I hear.

One of the many bags of mystery to be found, pro-tip, the good stuff is often at the bottom. As it turns out I have a feeling will be seeing a lot more of these.

Space grade high quality solar panels manufactured in Japan. Likely destined for use on a commercial satellite, and never even opened. They have been carefully looked after and stored for a weeee while, aged like a fine spirit. Among the undoubtedly long and prestigious chain of custody holders was Anchor Electronics the last standing brick and mortar provider of fine vintage, new and weird components.

I got a look at some of Kazu's latest handy work, a v0.2 tracker that's been under test.

After a thorough trip up and down and all around the fine wares on offer, it was time to call it a day and explore the wonders that I had acquired from a WWII era "Pipsqueak" to a doughnut shaped solar panel array. My pocket was a few grams lighter of cash and GPS modules bound for the sky, and replaced with pounds of new to me gear.

We had an excellent gathering of exceptional Amateur Radio Operators talking about various projects from Martin's thoughts on elevation control, to current assembly and testing of AVR based PCB's and experiments with new solar panel configurations.

General Agenda

• New Tracker/Kazu
• Solar Array/David, Beau, Rikke
• Manufacturing Trackers/Beau
• Controllable Altitude Balloon/Martin, David
• Lightweight Crossband Repeater/Martin
• Chabot Space and Science Center/Martin
• Calaveras County Public Schools/David
• Drone Rules Explained/Robert

Continuing on from our first experimental floater launch last year, the focus shifts to 2023 and the development of a totally new design! This was posted earlier at https://sf-hab.org/2022/10/29/new-trackers-underway/

Kazu AG6NS and W6MRR have been working on a couple of trackers. One is a dual band 2/20 m APRS/WSPR with other modes coming. It is based on an ATMega1284 processor, which is a 328 (used currently) with more memory and and running at 10 MHz, the safe limit for 3.3 V operation. Kazu has come up with code for it and a revised PCB is being worked on. The other is a Raspberry Pi Pico based tracker. This is a longer range project. It will use the same Si5351 based modulator and filters for 2/20 m. The Picos are attractive as they have a dual core ARM Cortex-M0+ @133MHz which is far more powerful than the ATMegas. The RP2040 chip has instructions for DIYing a board. However, the Raspberry Pi Pico as is, was the easiest path to start working on a design. Due to the chip shortage, it may end up using through hole components for the output filters.

We are looking at a lot of fun things that can be done – SSTV data and cam, voice ID over VHF, crossband repeaters, and latex floaters.

The ongoing work and interest continues with Kazu's coding and PCB development to use a RP2040.

While this is the start of a new hackaday.io project, you might have caught wind of some of our balloons at the last Supercon