point. During this test, the pointer of the voltmeter in the
(2) TEST PROCEDURE.
tester shall fall at 115 volts plus or minus 5 volts. The
(a) Turn switch no.
1 to the "FLUX
frequency of the 115 volt ( 5 volts) current shall be 400
VALVE CHECK" position; switch no.
3 to the
cycles (16 cycles), as indicated by the frequency meter
"CALIBRATE" position, and bring the Adj. stop of switch
no.
4 to bear on the knob in its extreme
of this tester. The phase rotation shall be ABC as
counterclockwise position.
indicated by the green panel light. If the red light comes
(b) Turn switch no. 4 until the pointer of
on, the phase rotation is wrong. Also in conjunction with
the milliammeter deflects to 150 volts. Return switch no.
phase rotation, the "A" leg of the three phase current
4 to the "OFF" position leaving Adj. stop in the position
should always be grounded, should the system have a
established by the knob setting where it shall remain for
ground. To check this, turn switch no. 1 to "GROUND
the remainder of this test.
CHECK" position, connect Test Lead no. 50A7513 to the
(c) To check the exciter coil of the
ground test jack and connect the other end of this lead to
transmitter, turn switch no. 3 to the "EXCITER" position
the aircraft structure. The green light shall not light.
and turn switch no. 4 against the stop. The pointer of
Should the green light come on, then "A" leg is not
the milliammeter shall fall within the portion of the scale
grounded. Disregard the red light as it has no bearing on
arc marked "EXCITER."
this test.
(d) Return switch no. 4 to the "OFF"
b. SLAVE CHECK. The following procedure shall
position and turn switch no. 3 to the "A" position. In this
be followed in checking the slaving of the J-2 Compass.
position, one secondary coil of the Flux Valve will be
(1) LEAD CONNECTIONS.
checked. The pointer of the milliammeter shall fall within
(a) Connect lead 47B7488 to the 10-pin
the portion of the scale arc marked "A-B-C.'
receptacle in the tester and the receptacle end of this
(e) The procedure referenced in the
shall be connected to the 10-pin plug of lead 47D7493.
previous paragraph shall be repeated for positions B and
(b) Disconnect the planes' 17-pin plug
C of switch no. 3 to check other secondary coils of the
from the type S-3( ) Directional Gyro receptacle and
transmitter. Any openings or shorts in the transmitter will
connect the 17-pin plug of lead 47D7493 to the type S-3(
cause substantial changes in the meter readings and the
) Directional Gyro. Connect the planes' 17-pin plug to
pointer will fall outside of the crosshatched area.
17-pin plug of lead 47D7493.
4-7.
FIELD CHECKING THE SLAVED GYRO
(2) TEST PROCEDURE.
MAGNETIC COMPASS TYPE 1-2.
(a) With the compass not running, switch
a. POWER CHECK. The following procedure shall
no. 1 of the tester shall be turned to the "SLAVE
be followed in checking the power supplied to the
CHECK" position and switch no. 2 to the `0" position.
amplifier under test.
The letters "L" and 'R" of switch no. 2 have reference to
(1) LEAD CONNECTIONS.
slaving of the indicator clockwise and counterclockwise
(a) Connect lead 47B7489 to the 4-pin
rotation only when the ship is in a North heading. When
receptacle In the tester and the receptacle end of this
the ship is in any other position, the letters "L" and "R"
lead shall be connected to the 4-pin plug of lead
shall be used as reference accordingly. "R" designates
47B7492.
planes' direction of turn; therefore, the compass rotates
(b) Connect lead 47B7488 to the 10-pin
counterclockwise while "L" position rotates compass
receptacle in the tester and the receptacle end of this
clockwise.
shall be connected to the 10-pin plug of lead 47B7492.
(b) Turn on ship's power and observe the
(c) Disconnect the planes' 14-pin plug
fast slaving. Turn switch no. 2 to the "L" or the "R"
from the A2 amplifier receptacle and connect the 14-pin
position to test for fast slaving clockwise position and
plug of lead 47B7492 to this amplifier receptacle.
counter clockwise rotation. After fast slaving completes
Connect the planes' plug to 14-pin plug of lead 47B7492.
its cycle, the gyro shall precess at a rate of not less than
(2) TEST PROCEDURE.
1-1/2 degrees nor more than 6 degrees per minute.
(a) Turn switch no. 1 of the tester to
Switch no. 2 shall then be returned to "O". The gyro
'POWER CHECK' position; switch no. 5 to the '28 v D-C'
shall precess back to null. Turn switch no. 2 to "R"
position, and turn on the ship's power. After the rotor of
position. The gyro shall precess to right at a rate of not
the indicator has come up to speed, a reading of the
less than 1-1/2 degrees nor more than 6 degrees per
voltmeter shall be taken. It shall be 28 volts plus or
minute. Switch no. 2 shall be returned to "O" position.
minus 2 volts.
The gyro shall precess back to null.
(b) Switch no. 5 shall be rotated to the
c. FLUX VALVE CHECK. The following procedure
three phases of the 115 volt, 400 cycle current, AB, BC,
shall be followed in testing continuity of the Flux Valve.
and AC respectively, and a reading of the voltmeter
(1) LEAD CONNECTIONS. Lead connections
taken at each
are same as those specified in paragraph 4-7, a, (1)
except for connections to the amplifier. Disconnect the
14-pin plug from the amplifier.
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