LESSON 4
EQUALIZATION
SCOPE ............................. Equalizing telephone circuits to improve
amplitude-frequency
relationships
and
to
minimize envelope delay.
CREDIT HOURS ...................... 1
TEXT ASSIGNMENT ................... Attached Memorandum, para 4-1 thru 4-6
MATERIALS REQUIRED................ None
SUGGESTIONS ....................... None
LESSON OBJECTIVES
When you have completed this lesson, you should:
1.
Be aware of the importance of equalization of a telephone line.
2.
Know that amplitude-frequency distortion of a telephone line affect voice
quality and may also affect data signals.
3.
Know that envelope delay causes distortion of data signals, but has little
effect on voice quality.
4.
Know that equalization inserts corrective networks to compensate for line
characteristics.
5.
Know that equalization is always accomplished at the receiving end of a
line.
6.
Be able to analyze characteristics of circuits presented on graphs of
amplitude-frequency and envelope-delay response curves.
7.
Be able to determine delay values needed to compensate for envelope delay.
8.
Be able to determine amplifier gain to compensate for line and equalizer
loss.
ATTACHED MEMORANDUM
4-1. IMPORTANCE OF EQUALIZATION
All operations involving circuit conditioning use equalizers. These units
are designed to equalize the amplitude-frequency response of a telephone
circuit.
Best quality of voice or sound reproduction is achieved when the
response of a circuit is constant over the entire spectrum of frequencies being
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