Elenco Basic Electronic Experiments - Manual (Page 54)

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EXPERIMENT #37: ELECTRONIC KAZOO
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 29 (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 38 now.
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.