TM11-5895-846-14
e. Release the latches on the slide rails and
remove the upconverter from the rack.
f. Replace the upconverter by performing steps a
through e above in reverse order.
Section IX. MAINTENANCE OF ELECTRONIC FREQUENCY CONVERTER CV-3200/TSC
correct voltage indications are observed with A2
5-28. Scope
disconnected, A2 module is short-circuiting power
a. This section covers instructions and procedures
for testing and fault isolation, adjustment, and removal
Proceed to (4) below if incorrect observation is observed.
and replacement of the CV-3200/TSC frequency
(4) Disconnect drawer harness P4 at A3
converter, commonly called SHF downconverter drawer.
module connector J5 and repeat steps (1) and (2) above.
The test procedures are based on the use of built-in-test
If correct voltage indications are observed with A3
equipment and equipment available in the terminal. No
disconnected, A3 module is short-circuiting PS1.
additional support or test equipment is required.
to (5) below if incorrect observation is observed.
(5) Disconnect and remove A1 frequency
downconverter adjustments, modules, and other
(1) and (2) above. If correct voltage indications ate
within the frequency synthesizer module. Refer to
observed with synthesizer removed, synthesizer is short-
circuiting PS1. Test the frequency synthesizer. Refer to
frequency synthesizer submodules, and to paragraph 5-
module. Proceed to (6) below if incorrect observations
33 for the replacement of the downconverter drawer.
persist.
WARNING
DANGEROUS VOLTAGES EXIST IN
with a working power supply from upconverter drawer.
THE EQUIPMENT. Do not attempt
Note that upconverter and downconverter drawer power
any removal or replacement unless
supplies are identical and may be exchanged. Repeat
the equipment is in a nonoperating
steps (1) and (2) above with upconverter power supply
condition and all power circuit
connected to downconverter harness, P1 and P2. If
breakers on the power distribution
correct readings are observed, downconverter power
panel are in the OFF position.
supply PS1 (just replaced), is faulty and shall be tested
5-29. Testing and Fault Isolation
separately.
Also if the upconverter power supply
a. Testing the Downconverter.
indicates incorrect readings, the downconverter drawer
(1) Place the POWER circuit breaker to the
harness is short-circuiting the power supply and shall be
ON position and observe that the associated POWER
tested separately.
indicator is illuminated.
(7) Place the MONITOR switch to the SYNTH
(2) Place the MONITOR switch to each of the
position and the SYNTH MON switch to the 0 ERR
following positions and observe the MONITOR meter for
position. Check status of OUT OF LOCK indicator.
a correct indication.
If an incorrect indication is
(8) IT OUT OF LOCK indicator is illuminated,
observed, proceed to step (3) below. If a correct
adjust the FREQ TUNE control to the frequency setting
indication is observed at all positions, proceed to step (7)
on the FREQ SELECT MHz switches setting. As the
below.
correct frequency is reached, the OUT OF LOCK
Position
Indication
indicator should extinguish. If the indicator will not
+24 V X1
22 to 26
extinguish, proceed to step (14 below.
+ 15 V X 0.5
28 to 32
NOTE
- 15 V X 0.5
28 to 32
Care should be taken to ensure that
+6 V X 0.2
28 to 32
the OUT OF LOCK indicator is
-6 V X 0.2
28 to 32
extinguished when the FREQ TUNE
(3) Disconnect drawer harness P3 at A2
control is reading the same frequency
module connector J5 and repeat steps (1) and (2) above.
as that indicated by the FREQ
If
SELECT MHz switches.
(9) Check status of indicator bulbs for RCVR
FAULT, OUT OF LOCK, 1 MHz LOP, and 1 kHz LOOP
FAULT lights by pressing in light housing.
5-46