Elenco Electronic Playground 50-in-1 Experiments - Manual (Page 53)

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Now it’s time to make your own music. This experiment
will use the (almost) same circuit as the last one, so there
is no schematic or Wiring Checklist. The only difference
is that you will draw a new shape. A Kazoo is a musical
instrument that is like a one-note flute, and you change
the pitch (frequency) of the sound by moving a plunger
up and down inside a tube.
As before, take a pencil (No. 2 lead is best but other types
will also work), SHARPEN IT again, and fill in the shape
you see below. For best results SHARPEN IT again,
place a hard flat surface between this page and the
rest of this booklet while you are drawing, Press hard
(but don’t rip the paper), fill in each several times to be
sure you have a thick, even layer of pencil lead, and try
to avoid going out of the boundaries. Where the shape
is just a line, draw a thick line and go over it several
times. The black ink in this manual is an insulator just
like paper, so you have to write over it with your pencil.
Take one loose wire and touch it to the widest part of this
shape, at the upper left. Take the other loose wire and
touch it just to the right of the first wire. You should hear
a high-pitch sound. How do you think the sound will
change as you slide the second wire to the right? Do it,
slowly sliding all the way around to the end. The sound
changes from high frequency to low frequency, just like a
kazoo. Note: you may get better electrical contact
between the wires and the drawings if you wet the wires
with a few drops of water or saliva. This circuit is nearly the same as for Experiment 27
(Electronic Sound), so you can use the notes you took
there to estimate what the resistance is at various points
along your kazoo.
Be sure to wash your hands after this test, unless you’re
going on to Experiment 36 now.
EXPERIMENT #35: Electronic Kazoo
Shape to be Drawn
Use a SHARP No. 2 pencil, draw on a
hard surface, press hard and fill in
several times for best results.