Lesson 2/Learning Event 5
NOTE:
The first parameter (-8 dB to +20 dB) listed is for non-
secure voice circuits such as ringdown and telephone where
the frequency spectrum tested is from 0.4 kHz to 2.8 kHz.
The second parameter (-7 dB to +12 dB) listed is for voice
circuits such as facsimile and DC, where the DC is
converted
to
tone
on
a
single
channel
basis
for
transmission over radio systems.
The frequency spectrum
tested for this type circuit is from 0.6 kHz to 2.4 kHz.
Notice that the parameters are tighter for the single
channel digital circuits.
Step 3.
Under the V1 column move down to the next test
listed, which is Maximum Envelope Delay Test.
This test is not performed on a circuit assigned
a V1 parameter code, because there is not any
parameters listed in the column.
Step 4.
Move down the column to the next test listed,
which is Maximum Net Loss Variation. This test
will be performed on V1 circuits because it has
parameters listed in the column.
d. There is a total of 24 tests listed in DCAC 300-175-9 Extract, table
2, of which 16 are performed on voice circuits assigned V1 parameter codes.
Continue the procedure used in the above example to determine which of the
remaining tests must be performed on the circuit and the test parameters.
Also the same procedure is used to determine which test will be performed on
any voice circuit listed in table 1 and their parameters.
e. DCAC 300-175-9 Extract, Enclosure 1, tables 3 and 4 contain the
required information needed to determine the parameters for voice circuits
assigned X and Z parameter codes. The same procedure used in the example,
also applies to these tables.
f. Circuit conditioning is normally performed to satisfy the circuit
requirements, and nothing further.
Exceeding this requirement takes
additional time and perhaps additional equipment, as well as more frequent
routine checks of circuit parameters.
Since requirements for AUTOSEVOCOM
are more stringent than for any other type of service, circuits conditioned
to those requirements
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