LESSON 2
RADIO TRANSMISSION AND RECEPTION
SCOPE.....................................Signal
frequencies;
principles
of
and
transmission
lines;
modulation;
AM,
FH,
and
SSB
transmitting
and
receiving
systems;
frequency synthesizers, discriminators,
limiters, and detectors.
CREDIT HOURS..............................2
TEXT ASSIGNMENT...........................Attached Memorandum, para 2-1 thru 2-6
MATERIALS REQUIRED........................None
SUGGESTIONS...............................None
LESSON OBJECTIVES
When you have completed this lesson, you should:
1.
Know the extent of the AF and RF ranges.
2.
Know the various types of modulation.
3.
Know the
purposes
of
limiters,
discriminators,
and
frequency
synthesizers.
4.
Know how RF waves are radiated.
5.
Know the radiating characteristics of half- and quarter-wave antennas.
6.
Know the uses for the four most common types of transmission lines.
ATTACHED MEMORANDUM
Section I.
RADIO WAVE PROPAGATION
2-1.
SIGNAL FREQUENCIES
(Hz) to many megahertz (MHz), can be considered in two broad groups: AF and RF.
a. Audio Frequencies. The AF range includes frequencies that can be heard by
the human ear. The range of audible frequencies is approximately 16 to 16,000 Hz.
The higher the frequency, the higher the pitch of the sound. Audio frequencies are
used in electronic equipments that produce sound for the human ear, such as radios,
tape recorders, record players, television, and
309 L2
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