(2) Connect an audio-frequency indicating
device between pin 1 of V1 and ground.
c. Test indications beyond allowable limits will
Use Frequency Meter FR-67/U or it
require realinement or repair of the stage under test. A
equivalent.
complete final test must be repeated following any
repair or alinement.
(3) Turn the DEVIATION control fully
clockwise.
91. Output Tests
(4) Rotate the MODULATION selector to
a. Output Frequency Test.
1000-, 1600-, and 20KC.
(1) Connect an external frequency measuring
(5) The audio-frequency meter should
device to the R. F. OUTPUT jack. Use
indicate 1,000 cps, 1,600 cps, and 20,000
Frequency
Meter
TS-174B/U
or
cps, accurate to - 1 percent.
Frequency Meter TS-175B/U or their
b. Audio-Oscillator Distortion Test.
equivalents.
(1) Connect an audio distortion indicating
(2) Set the FREQ. RANGE-MC selector to
device between pin 1 of V1 and ground.
the 50-100 me position.
Use Spectrum Analyzer TS-723/U or its
(3) Set the MODULATION selector to OFF.
equivalent.
(4) Tune the signal generator to 50 me, 75
(2) Rotate the DEVIATION control to produce
me, and 100 me.
The respective
a full-scale reading on meter M1.
indications at the external frequency
(3) Set the MODULATION selector to 1000-,
meter should be within + 1 percent of the
1600-, and 20KC.
FREQ. IN MEGACYCLES dial setting.
(4) The indication at the distortion meter
b. R f Output Level and Calibration Test.
should not exceed .2 percent distortion at
(1) Connect Barretter bridge model 202B to
each position of the MODULATION
the R. F. OUTPUT jack through a fixed
selector.
attenuator SN2Z394.85. The Barretter
bridge will indicate 50,000 microvolts (uv)
93. Deviation Tests
when the signal generator output is
a. Deviation Multiplier Test.
100,000 uv.
(1) Connect Electronic Multimeter TS-505, U
(2) Set the FREQ. RANGE-MC selector to
to the green lead connecting S1 to C70 or
the 50-100 mc position, and the
to C67.
When measuring unknown
MODUI,ATION selector to OFF.
voltages, select the highest scale to
(3) Tune the signal generator to 50 mc.
protect the meter.
(4) Rotate the OUTPUT control to bring the
(2) Set the MODULATION selector to 1000-.
pointer of OUTPUT meter M2 to center
(3) Set the DEV MULT switch to the X10
scale (SET TO LINE).
position.
(5) The output voltage of the signal generator
(4) Set the DEVIATION control to produce a
must be 100,000 microvolts + 2 db.
full-scale reading at the external
(6) Repeat procedure outlined in (4) and (5)
voltmeter, on any convenient scale.
above at frequencies of-
(5) Set the DEV MULT switch to the X5
(a) 75 and 100 me on the 50- to 100-
position.
me range.
(6) The external voltmeter should indicate 1/2
(b) 100, 150, and 200 me on the 100-
scale +5 percent.
to 200mc range.
(7) Set the DEV MULT switch to the X1
(c) 200, 300, and 400 me on the 200-
position.
to 400mc range. (Use 200-400MC
(8) The external voltmeter should indicate
TRIMMER.)
1/10 full scale +5 percent.
92. Audio-Oscillator Tests
(9) Replace the instrument cover.
a. Audio-Oscillator Frequency Test.
b. RF Deviation Test.
(1) Remove the signal generator instrument
(1) Tune the signal generator to 100 me on
cover.
the 50100 me band.
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