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Sometimes it can be very
difficult to find a rocket once it has landed on the ground. It depends on
the type of ground cover and whether you have a good idea or no idea at
all where it came down. I have found the items shown below to be
very helpful. |
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A good pair of binoculars
is extremely handy. These are especially useful because they contain
a built-in compass that can be read while you are looking through them.
Cross hairs allow a precision compass heading to the landing site to be
obtained. They also have a built-in scale that allows the distance
to an object to be estimated.
These binoculars are made
by Nikon. They are marine grade waterproof 7x50 and are available
from Global Mart
as item #7443. |
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These binoculars are 7X
magnification and have
multicoated optics that produce an exceptionally bright clear image. Field of view: 367' at 1,000 yards. They
have a
rubber-armored,
shockproof metal body construction. They are waterproof, and fog proof.
This makes them dust proof for use out at a typical launch site. It
also makes it easy to clean the dust off by rinsing them in water.
These binoc's can also be mounted on a tripod. Size: 7.1" x 8.0".
Weight: 42.7 ounces. Exit Pupil: 7.1mm.
One
draw back to these particular binoculars is that they are the individual
focus type. Each eyepiece must be individually focused.
Global Mart
also offers a plastic body version that has a more convenient central
focus mechanism. It is item #7441 and is also made by Nikon and also
has the built-in compass. |
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Instead of walking a
compass heading to a landing site, it is often even more helpful and more
accurate to have
someone "talk" you along a line of sight to the observed landing location by using
a pair of two-way walkie-talkie style radios.
This is a T6250 two-way
radio from Motorola. It can communicate on both the GMRS and FRS
frequency bands. It transmits at 1W on the GMRS channels and 0.5W on the
FRS channels. It can also tune into the NOAA weather service
broadcasts.
Information about Motorola two-way radios. |
Click here
to visit the Garmin eTrex web site.
View eTrex Owner's
manual (PDF document). |
This is a relatively
inexpensive GPS receiver that can also be used to travel to a predefined
spot. It can be especially handy when you can not travel in a straight
line to the observed landing site. Or when you can not be seen by an
observer to talk you to the landing location.
The best way I have found
to use this particular unit is to first get a compass heading with the
binoculars. Then set this unit to navigate to the spot where I was
standing when I took the compass reading. The landing site is then
on a bearing of 180 plus the compass reading. I can then head toward
the landing site and if I have to deviate I can easily get back onto the
proper line by moving back to the calculated bearing. This unit will also
display the distance from the original spot so I can easily tell how far
out I am.
There are also more
expensive GPS units from
Garmin
that have more convenient navigation features than this one. I found
this one for $99 at an Office Depot but they can also be found almost
anywhere that GPS units are sold. |
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The ultimate tool for
locating rockets is a radio beacon. The pictures below show a unit
from Jim Walston Retrieval Systems. (725 Cooper Lake Rd., S.E., Smyrna,
GA, 30082, 707/434-4905). Another source for small
transmitters and sensitive receivers is at
Wildlife
Materials.
A small transmitter is
placed in the rocket. A receiver is then used along with a
directional antenna to hunt down the transmitter once the rocket has
landed. This unit has a range of at least 1-2 miles when the
rocket is on the ground, although it does depend on how the antenna is
orientated. It has a much longer range while the rocket is in the
air. Perhaps as far as 10-20 miles, but I have never needed to
confirm that. |
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This shows the
Walston
transmitter and three Eveready #392 button watch batteries ready to be
installed. This small transmitter has a braided flexible wire 19"
long that serves as an antenna. The transmitter is so small that is
can be easily fit into virtually any high power rocket and even most low
power model rockets. The transmitter only weighs 7 grams. |
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The three watch batteries
are installed. I have never tested exactly how long these batteries will
last. I know it is at least 2-3 days, but I always use a fresh set
when attending a new launch. This transmitter operates at 216.095 MHz. |
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This is the
TRX-3S receiver
from Walston. It runs on eight AAA batteries. It has three channels
and weighs just under one pound. It connects to a directional
antenna (not shown) with a simple BNC cable. The signal strength is
displayed on an LED bar graph and is also made audible with a built-in
speaker. The transmitter sends out a short beep about once every 1-2
seconds. The beep gets louder as the directional antenna is pointed
more toward the transmitter. |
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I have used this unit to
find rockets that went completely out of sight. Even though I had no
idea where it came down, it was very simple to find it with this unit.
It was especially handy at the LDRS-18 launch site in Argonia Kansas
because the winds there were taking rockets into the nearby Milo fields.
The Milo was shoulder height and made finding rockets without a
transmitter extremely difficult. Although the Walston system is not cheap,
it has paid for itself many times over by recovering rockets that would
otherwise have been lost. The other obvious advantage is that it
allows for a quicker recovery without a long time consuming search.
This leaves more time for flying more rockets during a launch day.
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Tips and Tricks for using a
Walston System |
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Sue
McMurray is a very experienced, expert Walston user. She posted an
excellent article about using the system to the rec.models.rockets news
group on Sept 28, 1999. Her writing is entertaining and extremely
informative. She describes a number of very clever techniques.
Click here to view Sue's words of wisdom. (PDF document) |
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