GCARC Ballooning Adventure
Balloon Launch Postponed Until Early July 2024
Editor's Note : "The balloon launch has been postponed because a potential opportunity has arisen to have the lifting gas and related supplies donated to the Foundation and the school, and we need time to explore that option. Because of Field Day and other June activities the launch won't take place until early July. This will also give us more time for testing and configuration."
"For anyone interested in tracking the balloons already floating around the world check out the link below. In particular, the W8BI-12 balloon was launched at the Dayton Hamvention and has travelled east and was last tracked off the coast of Japan. It's carrying an APRS tracker that will only report when within range of APRS internet gateways, which are not numerous in many parts of the world. Our balloons will carry a WSPR tracker on 20 meters which should give us many more reports and allow more consistent tracking.
We'll use software to link those WSPR reports to https://amateur.sondehub.org and aprs.fi. The Monday night TechNet session on June 10 will cover the various balloon tracking options, both by radio and internet."
73 de Jon WB2MNF - May 29, 2024
"For anyone interested in tracking the balloons already floating around the world check out the link below. In particular, the W8BI-12 balloon was launched at the Dayton Hamvention and has travelled east and was last tracked off the coast of Japan. It's carrying an APRS tracker that will only report when within range of APRS internet gateways, which are not numerous in many parts of the world. Our balloons will carry a WSPR tracker on 20 meters which should give us many more reports and allow more consistent tracking.
We'll use software to link those WSPR reports to https://amateur.sondehub.org and aprs.fi. The Monday night TechNet session on June 10 will cover the various balloon tracking options, both by radio and internet."
73 de Jon WB2MNF - May 29, 2024
Editor’s Note : “The balloon team had targeted this Saturday June 1st to launch the WSPR balloon but we're still in the process of sourcing the hydrogen lift gas and it's unlikely that we'll have everything together by Saturday. We'll announce when we're ready to launch it - hopefully by June 8th.”
73 de Jon WB2MNF - May 28, 2024
73 de Jon WB2MNF - May 28, 2024
The GCARC’s Ballooning Adventure Begins On Saturday, June 1, 2024!
By Jon Pearce, WB2MNF
By Jon Pearce, WB2MNF
As if our Club didn't already have a full plate of activities, we'll be launching a balloon on June 1st that we hope will circumnavigate the earth sending back WSPR messages on 20 meters! Here's how that will work.
Several months ago the Club was contacted by Club member Joseph Lee N2BNJ, who's also a school board member of the Upper Deerfield Township Schools. Joe was asking if the Club would be interested in developing a STEM program possibly featuring Amateur Radio for students in the Woodruff Middle School. Since supporting Amateur Radio education is an important goal of every group, we immediately jumped on board and started discussions as to the type of activities that might be interesting to students at that level. After evaluating several options, launching and following a circumnavigating balloon carrying an Amateur Radio transmitter was determined to be the best option. |
This will demonstrate ham radio and provide a multitude of educational opportunities for kids in many related scientific areas.
These activities will begin in the fall, but it was obvious to our team that our first balloon launch couldn't be the large public event that would occur with the school, and that we had to assure ourselves that we had the skills and materials needed to create a successful launch. So a group of Club members started researching websites, watching videos, and slowly building a knowledge base on balloon launching, focusing on learning the best practices of other groups who have had successful ballooning activities.
The Balloon
After evaluating a number of products we selected the SBS-13 balloon (Figure 1) made by Scientific Balloon Solutions (https://www.scientificballoonsolutions.com). This balloon is used by several successful groups and appears to be the current choice of successful Amateur Radio balloonists. The balloon gets partially filled with hydrogen or helium (we're using hydrogen because of its lower cost and greater lift characteristics) until the lift generated by the balloon is approximately 7 grams greater than the weight of the payload. This is measured by attaching the balloon to a weight on a gram scale and slowly inflating the balloon until it lifts the weight by the necessary amount. The bottom of the balloon is then heat sealed, connected to the payload, and launched.
The Payload
The payload of circumnavigating balloons includes a transmitter, solar cells, and one or more antennas. Virtually all circumnavigating balloons utilize the WSPR protocol on HF frequencies because of its ability to be decoded at low signal levels over long distances. In addition, some groups have also included an APRS transmitter for greater location definition over populated areas, but we chose not to do this on our first launch because of the significantly increased cost of those units.
These activities will begin in the fall, but it was obvious to our team that our first balloon launch couldn't be the large public event that would occur with the school, and that we had to assure ourselves that we had the skills and materials needed to create a successful launch. So a group of Club members started researching websites, watching videos, and slowly building a knowledge base on balloon launching, focusing on learning the best practices of other groups who have had successful ballooning activities.
The Balloon
After evaluating a number of products we selected the SBS-13 balloon (Figure 1) made by Scientific Balloon Solutions (https://www.scientificballoonsolutions.com). This balloon is used by several successful groups and appears to be the current choice of successful Amateur Radio balloonists. The balloon gets partially filled with hydrogen or helium (we're using hydrogen because of its lower cost and greater lift characteristics) until the lift generated by the balloon is approximately 7 grams greater than the weight of the payload. This is measured by attaching the balloon to a weight on a gram scale and slowly inflating the balloon until it lifts the weight by the necessary amount. The bottom of the balloon is then heat sealed, connected to the payload, and launched.
The Payload
The payload of circumnavigating balloons includes a transmitter, solar cells, and one or more antennas. Virtually all circumnavigating balloons utilize the WSPR protocol on HF frequencies because of its ability to be decoded at low signal levels over long distances. In addition, some groups have also included an APRS transmitter for greater location definition over populated areas, but we chose not to do this on our first launch because of the significantly increased cost of those units.
The transmitter (Figures 2 & 3) that we selected is made by ZachTek (https://www.zachtek.com) and comes as a mostly assembled PC board with two super capacitors that need to be soldered onto the circuit board. It's programmed through a serial connection which is then removed before flight. Power is obtained from 2 solar cells mounted at angles on the board to create maximum illumination from sunlight.
The whole device is tiny and virtually weightless - the transmitter itself weighs less than 9 grams and the solar cells weigh about the equivalent of a sheet of paper. Mike Thompson KG4JYA assembled and programmed both of these, and we'll hang them outside of the Clubhouse for testing until the launch date.
The whole device is tiny and virtually weightless - the transmitter itself weighs less than 9 grams and the solar cells weigh about the equivalent of a sheet of paper. Mike Thompson KG4JYA assembled and programmed both of these, and we'll hang them outside of the Clubhouse for testing until the launch date.
The payload is hung from the balloon from a 17 foot length of fishing line and also a 17 foot length of enameled #36 wire that forms the top half of a vertical 20m dipole. Below the transmitter is another 17 foot length of wire completing the lower half of the dipole. Figure 4 shows this configuration for one of W5KUB's launches although we're not using the APRS transmitter that he is including. Although the transmitter only runs about 20 milliwatts it can still be heard at great distances. Mike set it up at a location in Michigan and was received as far away as Florida, and with the balloons riding at about 45,000 feet the coverage area should be significantly better. Some balloonists have been reporting that they were able to follow their balloons on the radio virtually in real time. |
Tracking (Reference Figures 5, 6, 7, and 8)
There are several methods of tracking the satellite, some involving actual radio reception while others utilize the worldwide WSPR receiving network with some supplemental work done to get the data onto various websites. Direct reception of WSPR signals is done using the standard WSJT program in WSPR mode (Figure 5), and listening on 14.095.600 MHz, the standard WSPR frequency. WSPR transmissions are two minutes in length, but an additional 2 minutes is needed to send the last two digits of the six digit grid square, so it takes 4 minutes to gather all of the information from one transmission. Hams with decent 20m receiving antennas may be able to track this balloon themselves.
For those without radios and to access the worldwide WSPR receiving network at the https://www.wsprnet.org/drupal/wsprnet/spots website receives and tracks WSPR reception (Figure 7) throughout the world. It displays it in tabular and map formats and also allows database queries. Figure 6 shows Mike testing the transmitter connected to a dummy load while receiving at the Clubhouse HF station.
Finally, the https://sondehub.org website (Figure 8) is specifically designed for balloon tracking, displaying only WSPR signals from balloons.
Next Steps
At the time of this writing we have all of the components assembled other than the lifting gas, which is still in process. We have materials for two complete balloons and will be launching them individually with the second’s schedule predicated on the success of the first. Weather conditions for a launch must be dry with winds less than 10 mph.
If everything works out we’ll attempt to launch on Saturday, June 1, 2024 around noontime.
Check the GCARC e-mail reflector for announcements.
There are several methods of tracking the satellite, some involving actual radio reception while others utilize the worldwide WSPR receiving network with some supplemental work done to get the data onto various websites. Direct reception of WSPR signals is done using the standard WSJT program in WSPR mode (Figure 5), and listening on 14.095.600 MHz, the standard WSPR frequency. WSPR transmissions are two minutes in length, but an additional 2 minutes is needed to send the last two digits of the six digit grid square, so it takes 4 minutes to gather all of the information from one transmission. Hams with decent 20m receiving antennas may be able to track this balloon themselves.
For those without radios and to access the worldwide WSPR receiving network at the https://www.wsprnet.org/drupal/wsprnet/spots website receives and tracks WSPR reception (Figure 7) throughout the world. It displays it in tabular and map formats and also allows database queries. Figure 6 shows Mike testing the transmitter connected to a dummy load while receiving at the Clubhouse HF station.
Finally, the https://sondehub.org website (Figure 8) is specifically designed for balloon tracking, displaying only WSPR signals from balloons.
Next Steps
At the time of this writing we have all of the components assembled other than the lifting gas, which is still in process. We have materials for two complete balloons and will be launching them individually with the second’s schedule predicated on the success of the first. Weather conditions for a launch must be dry with winds less than 10 mph.
If everything works out we’ll attempt to launch on Saturday, June 1, 2024 around noontime.
Check the GCARC e-mail reflector for announcements.