D.F.’ing, anyone?
Sunday morning, Aug. 26, I had a call from Ron, K3NXF about a guy from Austin asking for help in locating a lost rocket. He had done a Google search on Kerrville, Ham and radio and found our Club web site. It seems the guy, Dave Hein, KE5LOL, had lost his rocket after a flight Saturday. It was launched on the Meek Ranch on Alfred Petsch road off highway 16 in Gillespie County. Unfortunately, Dave had the wrong frequency programmed into his receiver and didn’t hear the rocket, which goes up to 3000 ft. and parachutes down. So I called his cel-phone number and found out about where it might be, a description of the possible signal, and the frequency, 434.25 F.M.
I thought about getting out my old Handi-Finder D. F. unit, but it had been 15 years or so since I had used it. See: <http://www.handi-finder.com/> So I decided to just drive out to the location and listen on the car’s TM-D700 dual bander. Sure enough I could hear the beeping weakly on a short stretch of Alfred Petsch road about a mile North of highway 16. It would beep for a minute or so and then send KE5LOL in Morse code. I could also hear it very weakly on a very short stretch of highway 16 between Henke’s station and Kott road. So it seemed like it might be in the big grassy pasture between Alfred Petsch road and highway 16. I phoned Dave and gave him the news, and he indicated he would probably come out from Austin and look for it.
Later I had an e-mail from Dave thanking the Club and explaining what happened. See below.
I was actually able to find the documentation for the Handi-Finder, but it had a modification which was not shown. A Google search led me to find the modification which enables uni-directional reception. See: <http://members.aol.com/homingin/hfinderfix.html>
The Handi-Finder is set up for about 150 MHz, so it might not have been much help on 434 MHz. The intermittent transmissions would have made it difficult also. I’ll have to try it out on a steady signal to get the feel for how it works. The 162.45 MHz weather station should be a good one, since I can see the tower from here, if that’s really where it is.
From David Hein
I would like to thank the Hill Country Amateur Radio Club for helping me with my rocket Sunday morning. I launched it at a club launch at Meek Ranch on Saturday, but I was unable to receive a signal from the tracking transmitter in the rocket. Early Sunday morning I realized that I had set my receiver for the wrong frequency - 434.025 instead of 434.25. I discovered that an extra zero makes a big difference!
The transmitter contains a small battery, and I was unsure if it was still transmitting. I would like to thank your club for finding somebody to verify that it was indeed still transmitting. I live in Austin, and it’s a three hour round trip to go to the launch site and back. I probably wouldn’t have gone back to search for my rocket if I was unsure if it was still transmitting.
I located my rocket after searching for about an hour. It landed about 1,000 from the launch pad. This was actually quite close considering that the rocket went up to an altitude of 3,000 feet and descended under a parachute for about three and a half minutes. The rocket is only three feet long and 1.25 inches wide, so it’s almost impossible to find without a radio transmitter. If you are interested, you can get more information about the rocket at <http://home.swbell.net/davehein/ModX/mini29.html> .
Thanks again,
Dave Hein
KE5LOL
I did a Google search on the terms Kerrville, HAM and radio. The second link on the list was for your club. The rocket was about a half mile up Alfred Petsch Road, and about 1,000 feet to the east in the pasture. It was laying on the west side of a terrace hill, which means that the signal was blocked to the east. It took me about 20 minutes to get within 100 feet of it, and then I meandered around for 40 minutes trying to localize it. The terrace hill would block the signal as I walked around, which confused me for a while. The grass is a couple of feet tall so I had to be right next to it to see it.
I have thought about getting a GPS tracker. The transmitter I use is from Big Red Bee, and they also make a GPS tracker. It cost $300 versus $95 for the transmitter I'm currently using. There are certainly advantages to using a GPS tracker.
Dave
73, Harvey
K5HV
