TM 55-4920-402-13&P
Table 2-2. Strobex Controls and Indicators
Figure &
Index No.
Control/Indicator
Function
2-2-1
MODE 5-position switch
Position A is used to operate the unit in a slave
mode for main rotor tracking and tail rotor
balancing.
Position B is used for main rotor tracking.
It incorporates a locking oscillator that, while
locked to rotor rate by Magnetic Pickup
pulses, causes the Strobex to flash at one-per-
blade rate.
Position C incorporates a free running oscil-
lator to flash the Strobex at a maximum rate
of 1000-per-minute for speed (RPM) measur-
ing.
Position D is also a free running oscillator
that flashes the Strobex at a maximum rate
of 10,000 per minute for tail rotor tracking
and speed (RPM) measurements.
Position E activates a locking oscillator as in
position B, but operates at a flash rate of
10,000 flashes per minute. Primarily used
to track airplane propellers.
2-2-2
RPM dial
Controls the flash rate of the Strobex in all
positions except A.
2-2-3
TRIGGER switch
Turns the +28 vdc power ON and OFF.
2-2-4
FLASH TUBE
In its precision parabolic reflector, produ-
ces a high intensity collimated beam. The
reflective targets on the blade tips or rotor
grips are clearly visible under all outdoor
weather conditions.
2-2-5
28 VDC POWER indicator
Lights when the TRIGGER switch is in the
ON position.
Table 2-3. Tester Cintrols and Indicators
Figure &
Index No.
Control/Indicator
Function
2-3-1
Double Interrupter
Screws on edge of rotor disc serve as inter-
rupters. Double interrupter configuration
is shown. Removal of four screws converts
disc to single interrupter configuration.
2-3-2
RPM switch
Switch for high and low cam rate (RPM).
2-3-3
MOTOR ON switch
Switch for dc to motor.
2-3-4
CAM RATE (RPM) trim pots
Trim pots for precise adjustments of RPM.
2-3-5
Strobe disc
Strobe disc pattern on rotor disc shows a
stopped image, under ordinary fluorescent
room lights, when RPM is accurately adjusted.
2-3
