Students Analyze HAB-2’s Flight Data – Nashua Area Radio Society

The HAB team members in NARS have created a five-session curriculum to teach physics, atmospheric science, and radio technology that we use as part of our HABlaunches. The last session is the most fun of all – analyzing the telemetry data from our HAB’s flight to see what the students can learn from it.

Source: Students Analyze HAB-2’s Flight Data – Nashua Area Radio Society

We got together with the students who did our HAB-2 launch this week to analyze the data from the flight and to preview some of the videos that HAB-2 captured during its flight. You can read more about what we learned from the flight data on the Nashua Area Radio Society website via the link above

Fred, AB1OC

HAB-2 Sets Altitude Record! – Nashua Area Radio Society

We flew our High-Altitude Balloon for the second time this past weekend. Our second High-Altitude Balloon Flight (HAB-2) was part of a STEM learning project that we did with STEM club students at Bishop-Guertin High School in Nashua, NH. The students did all of the flight prep and launched HAB-2 at approximately 11 am ET from a school in Winchester, NH. Parents, teachers and local students joined us for the launch as did several members of our HAB team.

Source: HAB-2 Sets Altitude Record! – Nashua Area Radio Society

Our students prepared, launched, and tracked HAB-2 this past weekend. Their HAB made it to almost 118,000 ft! You can read more about the launch and the flight on the Nashua Area Radio Society’s website via the link above.

Fred, AB1OC

HAB-2 Launch This Saturday – How To Track Our High-Altitude Balloon

Source: HAB-2 Launch This Saturday – How To Track Our High-Altitude Balloon

The Nashua Area Radio Society is planning to launch another High-Altitude Balloon (HAB) this coming Saturday, October 28th at 15:00z (11 am Eastern Time) from Winchester, NH USA. Our Balloon will carry a 2m APRS transmitter operating on 144.390 MHz and will be using the call sign N1FD-11. You can also track our HAB via the Internet using aprsi.fi. We expect our HAB’s flight to last about 2 1/2 hours and reach an altitude of over 105,000 ft. The balloon will also be carrying two video cameras to capture near-space video during the flight.

Our HAB launch is part of a STEM learning project with local High School students here in New Hampshire. You can read more about our project and see a video from our previous HAB launch and flight on our website here. We hope that you’ll track our HAB!

 

Fred, AB1OC

High-Altitude Balloon Launch and Tracking

Our HAB at the Edge of Space (GoPro Capture)

Our HAB at the Edge of Space (GoPro Capture)

We made it to the edge of space! The image above was taken from our HAB at an altitude of over 90,000 ft!

After many months of work, raising funds to finance the project, teaching STEM sessions in local High Schools, and an open-house to test the Balloon Platform and to learn about Amateur Radio; our High-Altitude Balloon Project (HAB) Team finally got the chance to launch and track our Balloon. We launched our Balloon from the Elementary School in Winchester, NH.

Setting Up Our Gear

Setting Up Our Gear

Students, Teachers and Club Members came out to be part of the launch and to track our HAB. The first step was to move all of our gear to the center of the athletic fields at the school and organize all of our equipment.

Assembled Flight Platform

Assembled Flight Platform

Next, we attached the GoPro video cameras, satellite tracker and the battery pack for the Flight Computer and 2M APRS transmitter to the flight platform. We used an APRS capable HT to confirm that the flight computer and APRS transmitter were working.

Rigging the Flight Line

Rigging the Flight Line

We rigged the 40 ft. flight line which connected the HAB’s flight platform, recovery parachute and the balloon.

Balloon Inflation

Balloon Inflation

And then came the inflation of the balloon from the Helium tank. The winds were gusting to about 12 mph at this point which made inflating the balloon a little tricky. When filled, the balloon was about 6 ft. in diameter on the ground.

Launch!

Launch!

With both GoPro cameras running on the flight platform, we were ready to launch. A 10 second countdown and the balloon was up and away!

Tracking the HAB

Tracking the HAB

We watched the balloon from the ground as it soared off into the clouds. The 2M APRS tracking system worked perfectly and we spent the next several hours at the launch site, at lunch, and in our cars tracking the HAB on aprs.fi.

HAB’s Flight Path On APRS.fi

HAB’s Flight Path On APRS.fi

Our HAB’s flight path took it across Massachusetts where it reached a maximum altitude of 91,700 ft. above sea level (ASL).

Looking Upward at the Balloon (Near Burst)

Looking Upward at the Balloon (Near Burst)

The balloon reached a diameter of approximately 30 ft before it burst. After the balloon burst, the parachute deployed and the payload descended to a landing in the northeast corner of Rhode Island.

HAB at Recovery Site in Rhode Island

HAB at Recovery Site in Rhode Island

A combination of the APRS transmitter data and the on-board sounder allowed the landing location to be pinpointed and the flight platform recovered with help from a local resident.

The on-board GoPro video cameras captured some awesome video during our HAB’s ascent! All of the media captured by everyone who participated in the launch as well as the APRS data allowed us to produce the video above. Turn up your speakers and give it a play in full-screen mode to enjoy the experience what we shared!

By the time we had launched, school was at an end so we will have to wait until the fall to work with the students and teachers who were part of our STEM project to analyze the data from the flight. All in all, our HAB project has been an amazing experience for all involved. We are planning another HAB STEM experience and launch with additional schools in the fall.

We want to especially thank all of our donors whose generous contributions made this project possible.

Fred, AB1OC

 

An Amazing Amatuer Radio STEM Project – High-Altitude Balloon

Image Taken From Our High-Altitude Balloon at over 90,000 ft

Image Taken From Our High-Altitude Balloon at over 90,000 ft

Members of the Nashua Area Radio Club launched a High-Altitude Balloon (HAB) to the edge of space and back this past weekend. Our HAB carried a 2m APRS Transmitter and sent position and atmospheric telemetry to the ground during its flight. Our HAB was tracked by many folks using aprsi.fi during its flight via the N1FD-11 call sign.

You can see an amazing video of the flight include footage taken during our launch and from the balloon while in flight above.

Our HAB launch was part of a STEM learning project that our club did in partnership with several High Schools here in New Hampshire. You can read more about the project and our STEM work on our club’s Blog here.

Enjoy!

Fred, AB1OC
President, Nashua Area Radio Club

A Portable Satellite Station Part 2 – 2.0 Station Goals and Antenna System

M2 Antenna Systems LEO Pack On Display at Dayton 2016

M2 Antenna Systems LEO Pack on Display at Dayton 2016

We came upon the M2 Antenna Systems booth while walking around the exhibit halls at Dayton last year. M2 had one of their LEO Pack satellite antenna systems on display there. This got us thinking about building a new, more capable version of our portable satellite station. The LEO Pack is a relatively lightweight circularly polarized antenna system for working satellites using the 2 m and 70 cm bands. It turns out that AMSAT members can purchase the LEO Pack at a discount. Starting with the LEO Pack in mind, I began to lay out some goals for a new, 2.0 Portable Satellite Station:

  • Be capable of working all active Amateur LEO Satellites including those using linear transponders and digital modes
  • Be portable and manageable enough to be set up in an hour or less
  • Be simple enough to operate so that HAMs who are new to satellites can make all types of satellite contacts with a relatively short learning curve
  • Be manageable to transport and store
  • Utilize computer controlled antenna tracking to aim the antennas
  • Utilize computer control to manage radio VFOs to compensate for doppler shift
  • Be easy to transport and store
Computer Controlled Satellite Station Via MacDoppler

Computer Controlled Satellite Station via MacDoppler Software

We decided to take a computer controlled approach for both antenna aiming and Transceiver VFO management to meet our goal of making the station simple to operate for new satellite operators. After some research on the available options, we choose MacDoppler from Dog Park Software Ltd. for this purpose. MacDoppler runs under Mac OS/X and works well on our MacBook Air laptop computer which is very portable. This program also has broad support for many different rotator and transceiver platforms and is very easy to understand and use. Finally, the program features high-quality graphics which should make the station more interesting to folks with limited or no experience operating through Amateur Satellites.

With the satellite tracking software chosen, we made selections for the other major components in the 2.0 Portable Satellite Station as follows:

I will explain these choices in more detail as our article series proceeds.

Glen Martin Roof Tower

Glen Martin 4.5′ Roof Tower

Our solution to making the antenna system portable is built around a Glen Martin 4.5′ Roof Tower. This short tower is a high-quality piece made of extruded aluminum parts. The tower is very sturdy when assembled and is light in weight. We added a pair of extended “feet” to the tower which are fabricated from 36″ x 2″ x 1 /4″ strap steel. This gives the tower a firm base to sit on and allows us to use sandbags to weight it down (more on this later).

Our chosen Yaesu G-500 AZ/EL Rotator is a relatively inexpensive Azimuth/Elevation rotator which is suitable for light-weight satellite antennas such as those in the LEO Pack. This rotator can be installed as a single unit on the top of a tower or separated using a mast. We choose the latter approach as it is mechanically more robust and helps to keep the center of gravity for our portable antenna system low for improved stability.

Yaesu G-5500 Elevation Rotator

Yaesu G-5500 Elevation Rotator

Separating the Yaesu AZ/EL rotator requires a short mast and a thrust bearing to be used. The mast was made from an 1-3/4″ O.D. piece of EMT tubing from our local hardware store. The thrust bearing is a Yaesu GS-065 unit. Both of these pieces fit nicely in the Glen Martin Tower. The thrust bearing provides support for the LEO Pack and G-500 elevation rotator and greatly reduces stress on the azimuth rotator. We also added a Yaesu GA-300 Shock Absorber Mount to the azimuth rotator. This part provides shock isolation for and reduces strain on the azimuth rotator during the frequent starts and stops which occur during satellite tracking.

LMR-400 Feed-lines And Antenna Connection Jumpers

LMR-400UF Feed-lines and Antenna Connection Jumpers

We decided to use LMR-400 UltraFlex coax throughout our antenna system. LMR-400UF coax provides a good balance between size, flexibility, and loss for our application. To keep feed-line losses reasonable, we choose to limit the total length of the coax from the transceiver output to the antenna feed point to 50′. This results in a loss of about 1.3 dB on the 70 cm band. The result is that our planned IC-9100 Transceiver which has a maximum output of 75W on 70 cm will deliver a little more than 50W maximum at the feed point of the 70 cm yagi. This should be more than enough power to meet our station goals. Allowing a total of 15′ for antenna rotator loops and transceiver connections, we settled upon 35′ for the length of our coax feed-lines between the tower and the station control point.

Portable Tower Cable Connections and Base Straps

Portable Tower Cable Connections and Base Straps

We added some custom fabricated plates to the tower to act as a bulkhead for feed line and control cable connections and to mount our low-noise preamplifiers. The control connections for the rotators and preamps were made using 6-pin Weatherpack connectors and rotator control cable from DXEngineering. The control cables are also 35′ long to match the length of our coax feed lines. This length should allow the tower and the control point to be separated by a reasonable distance in portable setups.

Low-Noise Preamplifiers From Advanced Receiver Research

Low-Noise Preamplifiers from Advanced Receiver Research

We added tower-mounted Low-Noise Preamplifiers from Advanced Receiver Research to improve the receive sensitivity and noise figure for our satellite antenna system. Two preamps are used – one each for the 2 m and one for 70 cm antennas. While these units can be RF switched, we decided to include the preamp control lead in our control cable to allow for control of the preamp switching via sequencers. This was done to provide an extra measure of protection for the preamps.

Levels And Compass For Tower Setup

Levels and Compass for Tower Setup

We added a compass and pair of bubble levels to the tower assembly to make it easier to orient and level it during setup. This picture above also shows the Yaesu shock absorbing mount for the azimuth rotator.

Weight Bags To Anchor Portable Tower

Weight Bags to Anchor Portable Tower

Finally, we added a set of weight bags to securely anchor the tower when it is set up in a portable environment. These bags are filled with crushed stone and fasten to the legs of the Glen Martin tower with velcro straps.

LEO Pack Antenna Parts

LEO Pack Antenna Parts

With the tower and rotator elements complete, we turned our attention to the assembly of the M2 LEO Pack. The LEO pack consists of two circularly polarized yagis for the 2m and 70 cm bands. The 2m Yagi is an M2 Systems 2MCP8A which has 8 elements (4 horizontal and 4 vertical) and provides 9.2 dBic of forward gain. The 70 cm Yagi is an M2 Systems 436CP16 with 16 elements (8 horizontal and 8 vertical) and provides 13.3 dBic of forward gain. Both Yagi’s are meant to be rear mounted on an 8.5′ aluminum cross boom which is included in the LEO Pack. The picture above shows all of the parts for the two antennas before assembly. It took us about a 1/2 day to assemble and test the antennas and both produced the specified SWR performance when assembled and test in clear surroundings.

Assembled LEO Pack On Portable Tower

Assembled LEO Pack on Portable Tower

The picture above shows the assembled LEO pack on the portable tower. We attached a short 28″ piece of mast material to the cross boom as a counterweight to provide better overall balance and to minimize strain on the elevation rotator. The antennas and the two outer sections of the mast can be easily removed to transport the antenna system.

2m Circularly Polarized Yagi Feed Point

2m Circularly Polarized Yagi Feed Point

The LEO Pack yagis achieve circular polarization via a matching network which drives the vertical and horizontal sections of the antennas with a 90-degree phase shift. The phase shift (and a final 50-ohm match) is achieved using 1/4 wave delay lines made of coax cables. We configured our antennas for right-hand circular polarization. The choice between right and left-hand circular polarization is not a critical one in our LEO satellite application as most LEO satellites are not circularly polarized. The advantage of circular polarization in our application is the minimization of spin fading effects.

Green Heron RT-21 Az/El Rotator Controller

Green Heron RT-21 AZ/EL Rotator Controller

The final step in the construction of our antenna system was to add the rotator controller and test the computer aiming system. We have had very good results using Green Heron Engineering rotator controllers in our home station so we selected their RT-21 AZ/EL rotator controller for this application. The RT-21 AZ/EL rotator controller is really two rotator controllers in a single box. The rotator control parameters such as minimum and maximum rotator speed, ramp, offset, over travel and others can be independently set for each rotator.

Rotator Test Using MacDoppler

Rotator Test Using MacDoppler

The RT-21 AZ/EL Rotator Controller connects to our computer via a pair of USB cables. We run Green Heron’s GH Tracker software on our MacBook Air laptop to manage the computer side of the rotator controller and to provide a UDP protocol interface to the MacDoppler tracking software. The picture above shows the test setup used to verify the computer controlled antenna pointing system.

Mixed OS/X and Windows Software Environment

Mixed OS/X and Windows Software Environment

One challenge associated with selecting a Mac OS/X platform for computer control is what to do about the inevitable need to run Windows software as part of the system. In addition to the GH Tracker software, the WaveNode WN-2 Wattmeter and digital modem software for satellite/ISS APRS and other applications require a Windows run-time environment. To solve this problem, we use a virtual machine environment implemented using VMware Fusion and Windows 10 64-bit on our MacBook Air Laptop along with Mac OS/X. Using the Unity feature of VMware Fusion allows us to run windows apps such as GH Tracker as if they were native Mac OS/X apps. The picture above shows an example of this.

Rotator Controller and Software Configuration

Rotator Controller and Software Configuration

With the antennas removed from the cross boom, we tested the operation of the computer controlled tracking system. The Yaesu G-5500 AZ/EL Rotator have some limits as to its pointing accuracy and backlash performance.  Experimentation with the combination of the RT-21 AZ/EL rotator controller, GH Tracker and MacDoppler setups was required to achieve smooth overall operation. We finally settled on a strategy of “lead the duck” tracking. The idea here is to set up the rotators so that they over-travel by a degree or so when the computer adjusts them and couple this with a relatively wide 2-3 degree tracking resolution. This maximizes the overall accuracy of the pointing system and minimizes the tendency towards constant start-stop operation of the rotators during satellite tracking. Our current configuration for all of the elements involved in the tracking system is shown above.

With the antenna system complete and tested, we can move onto the next step in our project – the construction of a computer controlled transceiver system. We will cover this element in the next part in this series. Other articles in the series include:

You may also be interested in the satellite station at our home QTH. You can read more about that here.

Fred, AB1OC

A STEM Learning Project for Young People

High Altitude Balloon At The Edge Of Space

High Altitude Balloon At The Edge Of Space

As some of you may already know, Anita and I have been working with our local Radio Club on a project to promote STEM learning and interest in Amateur Radio among young people in our area. The idea is to work with kids grades 7-12 to plan, build, launch and recover a High-Altitude Balloon carrying Amateur Radio. Our balloon should be able to reach an altitude of about 100,000 ft before it bursts and the payload returns to earth via a parachute system. The payload will include a computer, GPS and a 2 meter APRS transmitter to record the balloon’s flight track, atmospheric data and altitude throughout the flight. The balloon will also carry a video camera and will capture a video record of the entire flight. You can learn more about our project here.

Project Team Members Will Analyze and Report On Scientific Data

Project Team Members Will Analyze and Report On Scientific Data

We are working with local schools to put together a team of young people to plan and execute our project. This will include designing the on-board science experiments, analyzing the data collected and providing a presentation about what was learned to fellow students and others who are interested.

You can learn more about our project and view a video that shows what our balloon flight will be like on our Club website. This project is part of our Club’s on-going program to promote interest in Amateur Radio among young people. The folks at HAMNation recently featured a video which included some information about our club’s activities for young people as well.

We are working to raise the necessary funds to enable the project to be completed during the current school year. We have setup a GoFundMe page to facilitate the fund raising aspect of our project. We know that we have many readers around the world who follow our blog and it would be wonderful if some of our readers could help us by contributing to funding our project.

Anita and I will continue to post information about our project here.

Best and 73,

Fred (AB1OC)