The launch was a test of two new electronic items, a home made g-switch and an FRS radio transmitter. The rocket was my standard 3.25" diameter PVC body tube, with the electronics module, X-form parachute and the T-2 motor. The motor was loaded with a light propellant load to limit maximum altitude. Two timers were used in redundant mode with two separate deployment charges.
The launch detect g-switch was being tested as an alternative/backup for the pull wire launch detection I have used in the past to initiate my timers. The FRS radio is intended to give some basic data during the flight and to help in recovering the rocket after landing.
Launch conditions were fairly good, wind about 7 to 15 mph and blowing in the direction I wanted the rocket to drift, it was partly to mostly cloudy, but the ceiling was above my apogee. The motor had been loaded the night before, and the timers and electronics set and checked at the same time. Once my van was loaded and the checklist gone through, Bill and I proceeded to the launch site. Bill set up the launch pad and controller while I prepped the rocket for flight. The FRS radio was turned on and set to transmit, the deployment charges were installed and the timers were turned on. The rocket was assembled and the motor and igniter installed in the rocket.
I used two video cameras, one I hand held to capture the entire flight, the other was set in the back of my van pointed at the launch pad. The second camera captures audio better, so I set one of my FRS radios near the second camera to record the audio portion of the flight.
5,4,3,2,1, launch!
Here's the launch from the camera in my van.
Here's the launch from the hand held camera.
Click Here for a video of the launch. (New video loaded 5.27.04; I downloaded new software to convert my avi videos to mpeg 1 format. Hopefully this will result in better quality and a format everyone has codec for.)This is from the camera in the van, while it only shows the liftoff, the interesting part is listening to the audio.
It was a perfect launch, quick off the pad and straight as an arrow. I had another FRS radio clipped to my pocket, so I was listening for the piezo buzzer indicating the timers had been started by the g-switch. A few seconds after liftoff, as the noise from the launch subsided, I could hear the the FRS radio transmitting the piezo buzzer tone, indicating the g-switch had worked. After a few seconds more, I could hear the deployment charges going off, first one, then a second later the other. The the sounds of the parachute deploying were next.
As we watched the perfect parachute deployment, the radio continued to transmit the piezo tone as the rocket drifted slowly back to the earth. Just before landing, the rocket went behind a small hill and the radio signal was lost. We loaded up the launch controller and started driving to the area we thought the rocket would be, as soon as we crested the small hill the signal was reaquired. We quickly spotted the rocket about 200 yards from the road, a good 1/2 mile from the launch site. The parachute is a little big for this rocket, and really comes down slowly, that's the reason it was so far from the launch site.
I tried the body shield method of signal location, and it seemed to work fairly well. With the receiver in front of my chest, I would turn around 360 degrees, the signal would be its weakest when my back faced the transmitter, indicating the location of the rocket. I hope to soon have a antenna to make direction finding even easier.
We recovered the rocket with no damage, and once back to my van the electronics were turned off and checked for signs of damage. All was well.
Lt-38 was a complete success. Both the g-switch and the FRS were proven to work well.