Category Archives: Portable Field Ops
Greg, N4KGL and I worked on a joint project to build and launch an APRS rocket payload. We finally got to launch it yesterday after a small delay due to field availability. It included the Mobilinkd bluetooth adapter, Baofeng Uv-5r HT and a eBay special android smartphone (appropriately from “Boost”).
Our goals were to:
- Have a successful launch and recover (of course!)
- Use APRS for tracking using stock Ham radio equipment and smartphone
- Use the on-board smartphone sensors to record audio and accelerometer data
- Map ground track using My Tracks for further analysis
- Laptop with a RTL-SDR dongle and USB GPS
- SDR# tuned to the APRS frequency 144.390
- APRSIS32, VNCViewer, UZ7HO SoundModem Software TNC
- VB-Cable Virtual Audio capture
- Linksys Router with DD-WRT and Homebrew antenna
Note: You can view the Google Doc prepared for this flight with more detail.
The ground station was connected via 802.11g while the rocket was sitting on the launcher. I was able to control the phone screen through VNC and start the audio recording, Sensor logger, APRS and My tracks while it was sitting on the pad waiting for launch. That capability was instrumental in starting and checking all the services prior to launch.
Field conditions were excellent, although it was a little windy at times and very hot. Greg prepared the rocket while I prepared the ground station and prepped the payload. Greg decided to try out a new rocket motor that he had never used before. It was a disposable J425R-14A high powered rocket motor. It performed flawlessly from start to finish and sounded awesome!
I was quite surprised in how the phone GPS performed. It lost GPS fix during the accent phase but quickly reacquired lock after chute deployment. I chose My Tracks to do the GPS logging because of the logging rate and it integrates well with other GPS software. I am sure there is something better/faster but this seemed to work well for this launch.
- Audio File from inside the rocket
- Comma Delimited File of Accelerometer Data
- Google Earth File from “My Tracks”
- GPX file of flight
Please visit Greg’s post for more pictures and info.
Video of Launch: The second half of the video is of smartphone audio synchronized with video, very cool!
I recently had the privilege to attend a SEARS (SouthEast Alabama Rocket Society) rocket launch this past Saturday, October 15, 2011 with Greg, N4KGL and Sonny, KK4CVV. It was a blast (pardon the pun). A great bunch of folks just out doing what they love and enjoying every minute of it. Ok, what does the have to do with Ham Radio? Greg Lane, N4KGL mounted a 20m Beacon inside a high power rocket to launch it over 1500 feet in anticipation that other QRP’ers were listening.
Greg prepared the RMS rocket motor, put in fresh batteries, packed the chute and put it on the launching rail. The proposed time to launch was at 1700 UTC. Everything was on schedule until the operational check of the beacon. With Greg’s portable Hamstick dipole raised and listening on the beacon frequency of 14.060 Mhz just a steady tone was heard. I assisted him in posting to www.qrpspots.com to notify of the five minute delay in launch time to troubleshoot the beacon problem. Greg quickly went out to the launch pad and fixed the issue. Beacon was loud and clear.
Ready to launch. 5..4..3..2..1 … We have lift off! Great launch! Listening carefully.. No Beacon.
Uh, Houston, we have a problem. Post flight recovery revealed that the forces acting on the rocket ripped the beacon from the antenna and parachute part of the tube. The beacon transmitter free fell to earth while the other parts of the rocket came down nice and slow by parachute. Thankfully Greg found all the pieces with the help of his Grandson. Despite the failure it was a great launch and a great day. I am sure Greg will go back to the drawing board to make the beacon fly another day… Enjoy the video. 73
Visit www.N4KGL.info for more information.
What a nice day to venture out and do some field operations. I decided to get out and enjoy the HOT summer day with some operating from a Park that is way off the beaten path. This probably is not a park that anybody will be visiting anytime soon.
I happened to be looking at some Florida parks on Google Maps and found this little Park, what I didn’t realize was how forgotten the Park really was. As I am sure you have guessed by now it is the LLoyd Hall Park. I have no idea what the real story behind it is. My adventure started off by following Google Maps Nav on my Droid, it lead me straight to a road that had a gate on it. I doubled-back and it told me to go north on E. Callaway drive. I figured I have gone this far, might as well complete the journey. I trucked on past East Callaway and onto a small dirt road, I thought to myself, “this should be fun, good thing I have a 4×4”. So on I went, Google Nav did some rerouting and was putting me on the path to my destination. It was a seemingly long trip, I could only do 15-25 Mph because it was so rough. That is probably why I didn’t see any speed limit signs, they knew you didn’t need them. After dodging big potholes and small ponds I finally made it. Nothing really indicated it was a park at all, there was just an old bread truck, an outhouse, a strange looking tinned roof building and a covered picnic table. Frankly it was kind of spooky.
As I was starting to setup, I heard a crack of thunder off in the distance. Then another, this time even closer. It was time to put everything back in the truck and see if it passes. After about 40 minutes the storm had passed and I could finish the setup. I was impressed with the band conditions and how well the dipole was doing. In the tradition of portable ops I decided to do all my contacts with QRP. The mode I chose was PSK31 on 20 meters. I was surprised how well the setup worked, I was able to get good DX: Spain, Cuba, and Puerto Rico. I landed a few US stations too, in NV and TX. It was a lot of fun, I look forward to operating in another far out place…