02-11-2012, 06:02 PM
Analog Communications
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Limited Warranty and Disclaimer
This CD-ROM software has been designed to assure correct
operation when used in the manner and within the limits
described in this Instructor's Guide. As a highly advanced
software product, it is quite complex; thus, it is possible that if
it is used in hardware configurations with characteristics other
than those specified in this Instructor's Guide or in
environments with nonspecified, unusual, or extensive other
software products, problems may be encountered by a user. In
such cases, Lab-Volt will make reasonable efforts to assist the
user to properly operate the CD-ROM but without
guaranteeing its proper performance in any hardware or
software environment other than as described in this
Instructor's Guide.
This CD-ROM software is warranted to conform to the
descriptions of its functions and performance as outlined in
this Instructor's Guide. Upon proper notification and within a
period of one year from the date of installation and/or
customer acceptance, Lab-Volt, at its sole and exclusive
option, will remedy any nonconformity or replace any
defective compact disc free of charge. Any substantial
revisions of this product, made for purposes of correcting
software deficiencies within the warranty period, will be
made available, also on a licensed basis, to registered owners
free of charge. Warranty support for this product is limited, in
all cases, to software errors. Errors caused by hardware
malfunctions or the use of nonspecified hardware or other
software are not covered.
Introduction
This Student Workbook provides a unit-by-unit outline of the Fault Assisted Circuits for
Electronics Training (F.A.C.E.T.) curriculum.
The following information is included together with space to take notes as you move through the
curriculum.
♦ The unit objective
♦ Unit fundamentals
♦ A list of new terms and words for the unit
♦ Equipment required for the unit
♦ The exercise objectives
♦ Exercise discussion
♦ Exercise notes
The Appendix includes safety information.
NEW TERMS AND WORDS
audio - signals that a person can hear.
electromagnetic waves - the radiant energy produced by oscillation of an electric charge.
intelligence signal - any signal that contains information; it is also called the message signal.
message signal - any signal that contains information; it is also called the intelligence signal.
Audio Frequency (AF) - frequencies that a person can hear. AF signals range from about 20 Hz
to 20 kHz.
Radio Frequency (RF) - the transmission frequency of electromagnetic (radio) signals. RF
frequencies are from about 300 kHz to the 1,000,000 kHz range.
carrier signal - a single, high-frequency signal that can be modulated by a message signal and
transmitted.
Modulation - the process of combining the message signal with the carrier signal that causes the
message signal to vary a characteristic of the carrier signal.
demodulation - the process of recovering or detecting the message signal from the modulated
carrier frequency.
DISCUSSION
• Analog signals are continuous; they vary in amplitude, frequency, and/or phase.
• Digital signals are discontinuous; they are either high (logic 1) or low (logic 0).
• Message signals (information) have low frequencies from 20 Hz to 20 kHz.
• Carrier signals have frequencies from 10 kHz to 1000GHz.
• Modulation is where the message signal changes a characteristic (amplitude, frequency or
phase) of the carrier signal so that the message can be transmitted at the higher carrier
frequency.
• Radio signals are transmitted by conduction through a wire or radiated through space.
• In the receiver, demodulation is the process of recovering the message signal from the
modulated carrier signal.
• Bandwidth of an AM signal is the difference between the highest and the lowest frequency
on each side of the carrier