Elenco Electronic Playground 50-in-1 Experiments - Manual (Page 47)

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The forerunner of today’s telephone system was the
telegraph, which was widely used in the latter half of the
19th century. It only had two states – on or off (that is,
transmitting or not transmitting), and could not send the
range of frequencies contain in human voices or music.
A code was developed to send information over long
distances using this system and a sequence of dots and
dashes (short or long transmit bursts). It was named
Morse Code after its inventor. It was also used
extensively in the early days of radio communications,
though it isn’t in wide use today except in amateur radio
(“ham” radio). It is sometimes referred to in Hollywood
movies, especially Westerns. This is the same oscillator circuit that you have been
using. Connect the wires according to the Wiring
Checklist. Press the switch in long and short bursts to
make a sound pattern representing the dots and dashes
shown in the table above. You can use Morse Code and
this circuit to send secret messages to friends in hearing
distance without others knowing what you’re saying. If
the sound bothers others in the room then you may send
Morse Code messages using flashes of light instead.
Use the same circuit as you used in Experiment 13 (The
Electronic Switch) and press the switch in the manner
shown here. During World War II Navy ships sometimes
communicated by flashing Morse Code messages
between ships using searchlights (they did this because
radio transmissions might reveal their presence or
position to the enemy).
EXPERIMENT #29: Morse Code
Wiring Checklist:
o 27-to-56
o 55-to-24
o 19-to-25
o 18-to-43
o 5-to-21
o 6-to-22
o 52-to-23-to-32
o 33-to-42-to-51
o 20-to-26
Schematic
A . _
B _ . . .
C _ . _ .
D _ . .
E .
F . . _ .
G _ _ .
H . . . .
I . .
J . _ _ _
K _ . _
L . _ . .
M _ _
N _ .
O _ _ _
P . _ _ .
Q _ _ . _
R . _ .
S . . .
T _
U . . _
V . . . _
W . _ _
X _ . . _
Y _ . _ _
Z _ _ . .
1 . _ _ _ _
2 . . _ _ _
3 . . . _ _
4 . . . . _
5 . . . . .
6 _ . . . .
7 _ _ . . .
8 _ _ _ . .
9 _ _ _ _ .
0 _ _ _ _ _
Period . _ . _ . _
Comma _ _ . . _ _
Question . . _ _ . .
Morse Code