TM 11-5835-241-13&P
demagnetization.
(7) Disconnect the demagnetizer from the power source.
(8) Replace the head cover on the recorder.
c. PLAY EQUALIZATION AND AZIMUTH ADJUSTMENT.
Alignment test tapes are required to perform equalization
and azimuth adjustment (table 1-2).
A running narrative on the tape
tells what test tone frequencies are being played and their level.
In order to hear the narrative and test tones, a high impedance audio
l mplifier with a speaker must be connected to the output jack of the
distortion analyzer.
The distortion analyzer is used in the vtvm
mode.
De-magnetize the head in accordance with paragraph b above
before performing this procedure.
(1) Remove protective cover from the play-record head by
removing two screws, lockwashers, and flat washers.
(2) Place the 3.75 ips test tape on the supply reel disk
and an empty reel on the takeup reel disk.
(3) Thread the tape and start it on the empty reel.
(4) Connect distortion analyzer, terminated in an 8-ohm
Connect
non-inductive resistor, to the EXTENSION SPEAKER jack.
oscilloscope and audio amplifier to distortion l nalyzer output.
(S) Depress POWER ON switch and set SPEED control to UP
3.75 ips position.
(6) Depress PLAY switch.
(7) Listen for 500 Hz reference level tone on the test
tape and adjust PLAY LEVEL control for 1.0V as indicated on the
This is the reference level.
distortion analyzer meter.
(8) Listen for the next tone (7500 Hz) and adjust head
azimuth adj screw for maximum indication on distortion analyzer.
(9) Listen for next tone (5000 Hz) and adjust 3.75
5-4
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