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Table 5-3.
Demodulator Circuits Functional Test
ACTION
Connect FSK source to
INPUT 1
Set source output to 0 dBm
Mark Frequency
=
1710 Hz
Space Frequency
=
1770 Hz
Baud Rate
=
50 Baud
Set Demodulator front panel
controls in the following
manner:
Af
=
30 Hz
MARK FREQ/Af
=
57
SPACE FREQ/Af
=
59
POLARITY
=
NOR
MODE
=
NOR
AMH
=
OFF
LOCAL/REMOTE
=
LOCAL
Monitor low level output
Energize Printer
Reduce source output
until errors appear
Return source output
to 0 dBm
Repeat steps six and
seven first with the
MODE switch in MARK
position and then with
the Mode switch in the
SPACE position
Reverse sense on the
FSK source and change
Demodulator POLARITY
switch to REV
5-5
EFFECT
Keying should be presented.
Front panel MARK and SPACE
LED's should indicate keying
Observe copy, should be
correct (source output 0 dBm)
Source output level should be
less than -60 dBm
Observe copy is correct
In both cases source level
should be less than
-55 dBm
Observe copy is correct
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