Eggfinders and tracking beacons: Part 1
The Thrifty Rocketeer continues...
As we come to the end of the year, I was reflecting upon the loss of my Red Nova rocket into a pond two months ago .
When I started in this hobby about five years ago, I heard tales of people searching for their missing rocket, loosing it in the brush, in the trees or in ponds. The horror tales of this scared me enough to try two things.
First, I started writing a contact number of the inside shoulder of all my low power rockets so that "If found, call XXX-XXXX for reward". Now, I had never determined what the reward was going to be, but I figured if someone turned up an errant rocket, the nosecone would be a focus of attention, and I might just get a phone call.
Coincidentally, last night I was flipping through a Tripoli club's web-page and found a sub-category of Lost and Found rockets. The most recent entry was for a 39mm rocket (or remnants) found, without any ID or further description. They said the casing was in really good shape, though the rocket itself was disintegrated.
This started me thinking about how and why people might get their rocket back, years after they were lost.
The second thought was to place a tracking beeper inside the nosecone or payload section to generate a beep every few seconds. Now, I wasn't clear at first if this was an audible beep that you would hear as you walked the fields nearby. But it occurs that it was electronic so that a hand-held receiver would hear the signal and lead you by signal strength, to the area or field when the rocket came down.
I started a search for a Ham Tracker on a few websites, and soon came up with a simple kit that transmitted within the HAM Radio band. That was good for me, cause I am a licensed Ham operator who has more than a few HTs to play with. XFM1 tracker at jerry_baumeister@msn.com
I have the skills to assemble the small kit, so I ordered the XFM1 for about $15 and it arrived around Christmas from "Jerry's". It's a small printed circuit board with two matching one foot long hook-up wires that act as an antenna. The unit is powered by two Li-ion watch batteries held in place by a twisted paper clip spring. There's a computer chip, and about a dozen other parts... resistors, capacitors, and what not... easily assembled and soldered in a half an hour.
Be aware that the small size of the circuit requires that GREAT CARE be taken to prevent solder bridges when soldering
I paid the slight premium for the kit version, rather than the pre-assembled one, and asked for the option to have my call-sign programmed into the CW tone that is transmitted once every 30 seconds. If not programmed to something different, the default is the Morris code for "XFM1" on the same frequency.... 147.455 Mhz. The range of this little transmitter is low, under a mile at 5 feet above ground.... farther if you're much higher in the air with no obstructions. (assuming it's hung up in a tree or something)
Of course, you also need not only a receiver for that frequency, but also an antenna tuned to it as well. The Thrifty Rocketeer will discuss construction of a cheap Yaggi antenna next time.
As we come to the end of the year, I was reflecting upon the loss of my Red Nova rocket into a pond two months ago .
When I started in this hobby about five years ago, I heard tales of people searching for their missing rocket, loosing it in the brush, in the trees or in ponds. The horror tales of this scared me enough to try two things.
First, I started writing a contact number of the inside shoulder of all my low power rockets so that "If found, call XXX-XXXX for reward". Now, I had never determined what the reward was going to be, but I figured if someone turned up an errant rocket, the nosecone would be a focus of attention, and I might just get a phone call.
Coincidentally, last night I was flipping through a Tripoli club's web-page and found a sub-category of Lost and Found rockets. The most recent entry was for a 39mm rocket (or remnants) found, without any ID or further description. They said the casing was in really good shape, though the rocket itself was disintegrated.
This started me thinking about how and why people might get their rocket back, years after they were lost.
The second thought was to place a tracking beeper inside the nosecone or payload section to generate a beep every few seconds. Now, I wasn't clear at first if this was an audible beep that you would hear as you walked the fields nearby. But it occurs that it was electronic so that a hand-held receiver would hear the signal and lead you by signal strength, to the area or field when the rocket came down.
I started a search for a Ham Tracker on a few websites, and soon came up with a simple kit that transmitted within the HAM Radio band. That was good for me, cause I am a licensed Ham operator who has more than a few HTs to play with. XFM1 tracker at jerry_baumeister@msn.com
I have the skills to assemble the small kit, so I ordered the XFM1 for about $15 and it arrived around Christmas from "Jerry's". It's a small printed circuit board with two matching one foot long hook-up wires that act as an antenna. The unit is powered by two Li-ion watch batteries held in place by a twisted paper clip spring. There's a computer chip, and about a dozen other parts... resistors, capacitors, and what not... easily assembled and soldered in a half an hour.
Be aware that the small size of the circuit requires that GREAT CARE be taken to prevent solder bridges when soldering
I paid the slight premium for the kit version, rather than the pre-assembled one, and asked for the option to have my call-sign programmed into the CW tone that is transmitted once every 30 seconds. If not programmed to something different, the default is the Morris code for "XFM1" on the same frequency.... 147.455 Mhz. The range of this little transmitter is low, under a mile at 5 feet above ground.... farther if you're much higher in the air with no obstructions. (assuming it's hung up in a tree or something)
Of course, you also need not only a receiver for that frequency, but also an antenna tuned to it as well. The Thrifty Rocketeer will discuss construction of a cheap Yaggi antenna next time.
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