TB 11-6625-2974-30
(5) Check the MT PRESENT indicator. It should be
(2) Connect oscilloscope to A5A4-J7. Adjust A5A4-
off.
R9 to obtain a pulse width of 1100 50 nS for
(6)
If the MT PRESENT indicator is working
the negative-going TTL pulses on oscilloscope.
properly, the performance standard is met. If the
(3) Set STE PRIME POWER AC and DC switches
standard can not be met, the ECCM module may
to OFF.
be faulty (refer to TM 11-6625-2974-13 for
(4) Remove extender card and reinstall ECCM
maintenance procedures).
module in card cage.
c. ECCM Pulse Performance Check.
4-7. Power Supply Al Calibration
(1) To prepare the signal generator, connect the
a.
+5 Vdc (A) Performance Check.
oscilloscope input to the signal generator output
(1) Connect cable W12 (P/O accessory kit) between
using coaxial cable and a 100-ohm termination.
J4 of PSM INTERFACES group and J6 of RTU
(2) Adjust signal generator to obtain the display
INTERFACES group on front panel.
shown in B, figure 4-9.
(2) Set STE PRIME POWER AC and DC switches
(3) Disconnect
oscilloscope
and
100-ohm
to ON. Set RTU PSM PWR POWER switch to
termination. Connect output of signal generator
ON.
Set RTU PSM PWR DC SOURCE
directly to front panel RTU INTERFACES BMT
switch to INT.
connector (fig. 4-1).
NOTE
(4) Connect oscilloscope probe to A5A4-J9 (fig.4-
All test jacks used in this paragraph are
10). Set trigger to internal.
in the PSM INTERFACES group on the
(5) Observe oscilloscope. The negative-going TTL
front panel (fig. 4-1).
pulses should have a pulse width of 500 + 50
(3) Connect DVM to +5 VDC(A) red (+) and gray (-)
nS.
jacks.
(6) Connect oscilloscope to A5A4-J7. Leave trigger
(4) Observe DVM. Reading should be +5.0 0.. If
set to internal.
the performance standard is met, go to
(7) Observe oscilloscope. The negative-going TTL
subparagraph c (below) for the next
pulses should have a pulse width of 1100 +
performance check. If not, go to subparagraph b
50nS.
(below) for adjustment.
(8) If the performance standards in steps (5) and (7)
b. +5 Vdc (A) Adjustment.
are met, perform step (9).
If
either
(1) Set STE PRIME POWER AC and DC switches
standard is not met, go to subparagraph d
to OFF.
(below) for adjustment.
(2) Remove power supply Al (refer to TM 11- 6625-
2974-13).
(9) Set STE PRIME POWER AC and DC switches
(3) Loosen 16 captive screws (fig.4-11) and remove
to OFF.
power supply cover.
(10) Remove extender card and reinstall ECCM
(4) Reconnect A3P9 to A1J1 on power supply
module in card cage.
(disconnected in step (2).
d.
ECCM Pulse Adjustment.
(5) Set STE PRIME POWER AC and DC switches
(1) Connect oscilloscope to A5A4-J9. Adjust A5A4-
to ON.
R8 (fig. 4-10) to obtain a pulse width of 500
50 nS for the negative-going TTL pulses on
oscilloscope.
4-13
