5-6. Pointer Stops Test
a. Pointer stops shall permit deflection of
The tests outlined in this standard are designed to
horizontal and vertical pointers to end dot without
measure the performance capability of repaired
interference. Pointer shall deflect slightly past end
equipment. Equipment that is to be returned to
dot, or approximately 10% beyond full scale
stock should meet the standards given in these tests.
deflection (para 4-23).
Refer to chapter 4 for test procedures.
b. With an overload current of 750 microam-
5-2. Applicable References
pere applied to either pointer, in either direction,
a. Repair Standards. Applicable procedures of
pointer will deflect to stop. Gradually and evenly
the depot performing this test and the general
reducing current to 130 microampere will cause
standards for repaired electronic equipment given
pointer to leave stop without tapping or vibrating
in TBSIG 355-l, TB SIG 355-2 and TB SIG 355-
the instrument. Break away current shall not be
3 form a part of the requirements for testing this
less than 130 microampere (para 4-23).
5-7. Pointer Clearance Test
b. Modification Work Orders. Perform all
modification work orders applicable to the ID-48A
With current applied to any combination of
before making the tests specified. DA PAM 310-7
mechanisms no pointer will interfere with operation
of any other pointer at any position or deflection.
lists all available modification work orders.
5-8. Sensitivity Tests
5-3. General Test Requirements
a. Horizontal and vertical pointers shall deflect to
The tests indicated in this chapter should be
end dots, either side of center, with 150 ± 7 . 5
conducted at a temperature of approximately
25°C. (77 oF.). The Indicator should be lightly
microampere applied to appropriate pins of
connector J1 (para 4-21).
tapped or vibrated when taking readings except
b. Horizontal and vertical flags shall leave stops
where otherwise stated.
with 125 ± 6.0 microampere applied and shall be
5-4. Terminal Resistance Test
concealed by mask when 250 ± 12.5 microampere
Resistance of each mechanism circuit shall be 1000
are applied (para 4-22).
±30 ohms, measured at connector J1 terminals
5-9. Response Time Test
The time required for the horizontal or vertical
5-5. Balance Test
pointer to reach 90 percent of its deflection
Glide path and localizer pointers shall be aligned
distance, counted from the instant current is ap-
with appropriate row of dots when in normal
plied shall be 1.2 seconds maximum (para 4-24).
vertical mounting position. Rotating Indicator 90°
left and right and to dial-upward positions shall not
cause pointers to indicate off dot furthest from
pointer (para 4-17).