TM11-5895-846-14
(6) Connect one end of the step attenuator to
attenuator between the 700 MHz modem and the 700
the loose end of the c/kt test cable. Adjust the attenuator
MHz IF IN connector.
(23) Place the IF IN switch into the 700 MHz
(7) Connect the 700 MHz modem drive cable
position, Locate R2 on the 70/700 MHz module A2 and
to the other end of step attenuator.
adjust R2 to just turn on the FAULT lamp. If the
(8) Place the upconverter MONITOR switch to
UPCONV FAULT lamp is already lit, adjust R2 until the
the IPA OUT position.
lamp goes out and then readjust R2 to turn on the
FAULT UPCONV lamp.
on module A5 and gain control R17 on module A2.
(24) Remove the test cable and attenuator and
(10) Loosen the front panel captive screw and
reconnect the modem cables to the corresponding IF
slowly extend the upconverter from the rack just enough
Input connectors. On the SHF filter/detector module A5,
to gain access to the switch and control. Check that the
place the APC switch to ON position. Close the
modem and amplifier/mixer cables are not under undue
upconverter drawer, tighten the four front panel captive
strain.
screws, dress the modem and mixer/amplifier cables into
(11) On the associated transmit modem, check
the cable trough, and close all cable access covers, and
that the XMT function switch is not in the OFF position
tighten the captive screws. On the front panel, connect
and that the ac power is on.
the 5 MHz cable to the 5 MHz OUT connector.
c. System Using Only 700 MHz Modem. Repeat
(12) On the SHF filter/detector module A5,
steps b(1) through (16) and steps b(24) and (25).
place the APC switch to the OFF position.
(13) On the 70/700 MHz upconverter module
d. System Using Only 70 MHz Modem.
A2, adjust gain control R17 for an indication of 25 on the
(1) Connect the test cable and attenuator to
monitor meter.
the 70 MHz IF IN connector. Turn the IF IN switch to the
(14) On the front panel, remove the c/kt test
70 MHz position.
cable and step attenuator and connect the modem drive
(2) Connect the 70 MHz modem drive cable to
cable directly to the 700 MHz IF IN connector.
the step attenuator (set at 5 dB).
(15) On module A5, place the APC switch to
NOTE
the ON position.
On the associated transmit modem,
(16) On module A5, adjust the IPA Out APC
check that the XMIT function switch
is not in the OFF position and that the
monitor meter. Place the MONITOR switch to the 700
ac power is on.
MHz position and adjust R16 on the A2 module for a
(3) On the SHF filter/detector module A5,
reading of 25. Return the MONITOR switch to the IPA
place and hold the APC switch to the test position.
OUT position.
(4) On the 70/700 MHz upconverter module
(17) Connect the test cable and attenuator to
A2, adjust the gain control R6 for an indication of 25 on
the 70 MHz IF IN connector. Turn the IF IN switch to the
the MONITOR meter.
70 MHz position.
(5) On the SHF filter/detector module A5,
(18) Connect the 70 MHz modem drive cable to
adjust fault control R5 to just turn on the upconverter
the step attenuator (set at 5 dB).
NOTE
adjust R5 until the lamp goes out, and then readjust R5
On the associated transmit modem,
to just turn on the FAULT lamp.
check that the XMIT function switch
(6) Release the APC switch from the test
is not in the OFF position and that the
position on the SHF filter/detector module A5, and place
AC power is on.
the APC switch in the OFF position.
(19) On the SHF filter/detector module A5,
(7) On the 70/700 MHz upconverter module
place the APC switch to the OFF position.
A2, adjust the gain control R17 for a reading of 25 on the
(20) On the 70/700 MHz upconverter module
MONITOR meter.
A2, adjust gain control R6 for an indication of 25 on the
(8) Remove the test cable and step attenuator
MONITOR meter.
from the 70 MHz IF IN and reconnect the modem cable
(21) On the SHF filter/detector module A5,
to the corresponding IF input connector.
adjust fault control R5 to just turn on the upconverter
(9) On the SHF filter/detector module A5,
place the APC switch to the ON position.
adjust R5 until the lamp goes out and then readjust R5 to
(10) On module A5, adjust the IPA OUT APC
just turn on the FAULT lamp.
(22) Remove the test cable and step attenuator
monitor meter.
from the 70 MHz IF IN and reinsert the cable and
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