On Target mirrors, how to make them,
and how to use them
Making On Target mirrors
- On Target mirrors actually consist of two mirrors
which are glued or taped together. Typically, the reflecting mirror is
larger than the sighting mirror which is attached to it. The larger
reflective surface is used to direct sunlight to your target, and the
sighting mirror is used to helping with aiming the beam of light.
- Some On Target participants like to use plexi-mirror
rather than glass mirror. I personally have not had good luck with
plexi-mirror. The silver plating of plexi-mirror does not scratch off
cleanly as it does with glass mirror. I have also found the thinner
plexi-mirror to be somewhat flimsy and sometimes not perfectly flat. The
big advantage of plexi-mirror is that it is much lighter than glass, and
thus more readily transportable to mountain tops. Also, it does not crack
or break as does glass mirror.
- To make an On Target mirror, you must scratch or
remove the paint and metallic film from a small circular area of each
mirror. I like to use a circle template, a very sharp pin, and an exacto
knife to remove the film. Once you have scraped as much of the film off as
possible, you can then use a pencil eraser to remove the last remnants of
the film. You then glue or tape the two mirrors together with the two
holes perfectly aligned.
- The larger the mirror, the greater the reflective
surface and the farther you can send your signal. Plans and designs for
larger mirrors will be available at the Kickoff Workshop on mirror-making.
Building and using a large mirror on the mountain-top is one of the most
fun and challenging aspects of On Target. Are you up to the challenge?
- Here are some great links that deal with
mirror-making (thanks to Richard Fowell for these links):
a. Here is a link to a mirror design
for a 2 foot-by-2 foot mirror from the Mesa Varsity Scounts
http://ontarget.mesavarsity.org/resources/Wham-Bam-Biggee.pdf
b. Here is a link that shows
designs for both a 2x2 foot and 3x3 foot mirror:
http://ontarget.mesavarsity.org/resources/OT%20Prog%20Feature.pdf
c. The Mesa Varsity scouts On
Target website has other great ideas:
http://ontarget.mesavarsity.org/resources/
d. Here is a link (KB7UZO’s
website) that shows front and back photos of a 2x2 foot mirror in action at
http://blog.ashcraft.ws/?p=33
(double-click on the photos to
see the full size)
Aiming On Target mirrors
- Using
an On Target mirror is fairly easy, though it appears somewhat difficult
at first. Practice will soon have you aiming your mirror like a
professional.
- Aiming
the mirror requires that you do two things at the same time. The first
thing to do is locate your target while looking through the hole in the
mirror. The large reflective surface should be facing the target and the
smaller sighting mirror should be facing your face.
- With
the mirror facing in the general direction of the sun and having spotted
your target through the hole, look in the small sighting mirror and find a
small dot of light. You will usually see this dot of light somewhere on
your face, your collar, or your shirt.
- Now
comes the tricky part. While looking at the dot of light and
simultaneously looking at the target through the hole, slowly adjust the
angle of the mirror so that the "dot" approaches the hole. By
crossing the dot back and forth over the hole you will be sending your
beam to your target.
- An
easy way to check yourself for accuracy is to aim at a license plate, a
reflective street sign, or a reflector that you place yourself. As you
bring the dot, the hole, and the target into line, these reflective
surfaces will really light up.
- A
3" or 4" mirror will send a noticeable signal for 15 to 20
miles, but larger mirrors will be necessary if you want to make longer
contacts. The smaller sighting mirrors are taped or glued on the corners
of larger mirrors to assist in aiming.
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