Who Calibrates Bird Slugs?
Well, time flies when you are getting old. After I wrote the last note, I
remembered that the article on home made directional wattmeters was in the
80's. I vaguely recall it was October 1983.
Today, I have all sorts of sophisticated test equipment, but still enjoy
rolling my own and calibrating it with simple equipment. Recently some of
my friends needed to measure the patterns of antennas. Although I have a
couple commercial field strength meters, I constucted a simple one then used
the signal generator to calibrate it. Once you have a calibrated standard,
you can build frequency compensated voltage dividers to allow you to measure
rf voltage with a fairly high precision.
I teach survival classes and you need to learn to use what you have. I once
demonstrated to a class that you could navigate with an old tennis shoe -
and be as accurate as with any small handheld compass - although not nearly
as quickly or as conveniently. And, I was in a map reading workshop where
we were reading a number of bearings using the pocket compass. I left my
compass in my pocket to see how I could do taking about 10 bearings with no
compass at all. I tied for first place. By simply dividing into
quadrants - by hand - you can get amazing accuracy. And, most of the people
in the class got at least one wrong answer by not thinking and using the
reciprocal.
But, I am amazed that when I learn something new it is often from some new
and inexperienced person who approached things from a different perspective
than I did.
73, Colin K7FM
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