Project:
A video/audio transmitting balloon with a remote controlled 180 degree pan/tilt video camera attached to a 35mm still camera with remote triggering.
Designer(s):
N8UDK
Description:
If you have already read the "ATV High Power rocket projects of 1992 and 1993" page you'll remember that every summer my friends and I travel to the tip of the upper peninsula of Michigan for a week of neat outdoor activities. For my 1994 summer project I designed something that would produce more than just two minutes of aerial video the rocket projects provided me years before. I built an ATV platform that floated a thousand feet above us, was left tethered all day, and had the ability to take 35mm pictures on command (for example when we launched a 70 foot rocket, but that's another story!) A small video camera was attached to the bottom of the 35mm camera. I could move the attached cameras remotely from the ground and watch what they were viewing. When the time came I then signaled the 35mm camera to take a picture. In addition to the video being received, I also received audio via a microphone on the platform which allowed me to confirm the 35mm camera took the picture (i.e. I heard the film advance.)
Some Technical Information:
The payload consists of a one watt PC Electronics transmitter (439.25 MHz out) attached to an horizontal dipole antenna. The 35mm camera and Chinon b/w video camera are installed into a custom made cradle. The cradle is mechanically attached to two Futaba servos allowing the cameras to pan and tilt. For additional strength and less stress on the pan servo I attached the top assembly and bottom assembly with a ball baring ring from a lazy-susan. To improve the rotational range to 180 degrees I programmed the Counterfeit Stamp computer to scale the outputs of the Futaba RC receiver. The Counterfeit Stamp computer also monitored the ground radio controller "landing gear" switch. When I flipped the switch the Counterfeit stamp activated a mini servo that pushed the shutter button on the 35mm camera. Why use a mini servo to push the shutter button and not hook a few wires internally to the 35mm camera? Simple, it is my wife's camera! For reception I used a custom built crossed dipole antenna with ground plane which attached to a P.C. Electronics down converter. The output of the down converter (on channel 3) feed my VCR and TV.
The platform tethering (attaching to the ground) hardware was simple yet effective. Attached to the video platform were three eye-screws forming a triangle. Kevlar line was attached to each of the eye-screws. My three assistants, using special kite spindles and gloves, simultaneously let out about 1,500 feet of line then tied them off to kite anchors that were pre-screwed into the ground. Their work was done until the end of the day! The platform was very stable. It never drifted and spun only slightly.
Hardware:
Hardware Sources:
Conclusion:
The ATV balloon platform served its' purpose well. Once tethered my friends and I were able to enjoy a spectacular view all day. I video taped hours of the rock solid P5 picture. It was really neat seeing small model rockets take off and land below the balloon. And most amazing, the dozens of incredible 35mm pictures of what I wanted, when I wanted, from 1200 feet above. When does the fun ever end?
- Chris Oesterling N8UDK
Fig 1.0 - "The Video platform"
Fig 2.0 - "Received transmission from the video platform as my friends spell GT"
