If you ever wanted to be a disc jockey, this is your
chance. This AM radio station lets you actually send
your voice through the air. You built an AM radio
transmitter in the last project, but it could send only
a single tone or a series of dots and dashes.
When you finish the wiring, turn on your AM radio
receiver and tune it to a weak station or silent
setting on the dial. Now, begin to talk into the
speaker while adjusting the tuning capacitor, until
you hear your voice on the air. This transmitter can
only send signals a few feet, so place your AM radio
close to the kit.
Transistor Q1 amplifies the audio frequency signal.
The amplified signal controls the amplitude of the
RF oscillator signal. The tuning capacitor and
antenna coil tune the RF signal to the setting on
your AM radio dial and send it through the antenna.
Transistor Q2 helps control the amplitude of the RF
signal. The NPN transistor is a part of the RF
oscillator and provides the primary amplification of
the RF signal (before the AF (audio frequency)
signal modulates it).
Notes:
EXPERIMENT #113: AM RADIO STATION
-134-
Wiring Sequence:
o
1-29
o
2-30
o
3-111
o
5-7-90-42-119
o
6-12-47-ANT
o
8-11-99
o
40-112-94
o
41-43-93-78
o
77-44-131
o
45-79
o
89-100-46
o
48-80
o
121-122
o
124-132
Schematic
Содержание EP-130
Страница 11: ... 11 I ENTERTAINMENT CIRCUITS ...
Страница 26: ... 26 II BASIC SEMICONDUCTOR AND COMPONENTS CIRCUITS ...
Страница 36: ... 36 III LED DIGITAL DISPLAY CIRCUITS ...
Страница 41: ... 41 IV A TOUR THROUGH DIGITAL CIRCUITS ...
Страница 49: ... 49 V MORE ADVENTURES WITH DIGITAL CIRCUITS ...
Страница 64: ... 64 VI THE WORLD OF TRANSISTOR TRANSISTOR LOGIC ...
Страница 77: ... 77 VII APPLICATION CIRCUITS BASED ON THE OSCILLATOR ...
Страница 88: ... 88 VIII BASIC OPERATIONAL AMPLIFIER CIRCUITS ...
Страница 116: ... 116 IX MORE ADVENTURES WITH OPERATIONAL AMPLIFIERS ...
Страница 129: ... 129 X COMMUNICATION CIRCUITS ...
Страница 136: ... 136 XI TESTING AND MEASURING CIRCUITS ...