TM 11-5840-281-35/1
(31) On Intermediate Frequency Amplifier
EL TARGET control maximum ccw, and STC switch
AM-3338/TPN-8, disconnect oscilloscope vertical input
OFF.
test prod from DET 5 testponint TP3607 and connect to
(3) Test equipment connected as shown in
DET 6 testpoint TP3608.
c. Procedures
(32) On radar test set, rotate OUTPUT
ATTEN. control ccw until pulse on oscilloscope equals
amplitude in (17) above.
NOTE
(33) On radar test set, record OUTPUT
When in precision scan (SCAN MODE switch
ATTEN. control dial setting. Setting should be 10 (-+2)
placed to NORM, 35EL, or 60 AZ), elevation
db more than setting recorded in (30) above.
Antenna AS-1291/ TPN-8 and azimuth Antenna
(34) On Intermediate Frequency Amplifier
AS-1292/ TPN-8 may be positioned by hand by
AM3338/TPN-8, disconnect oscilloscope vertical input
rotating knurled end of elevation Antenna Drive
test prod from DET 6 testpoint TP3608 and connect to
TG-114/TPN-8 drive motor shaft (located under
DET 7 testpoint TP3609.
cover on right side of elevation Antenna Drive
(35) On radar test set, rotate OUTPUT
TG-114/ TPN-8, as viewed from front of Radar
ATTEN. control to increase attenuation until pulse on
Receiver-Transmitter RT 818/TPN-18).
oscilloscope equals amplitude in (17) above. OUTPUT
ATTEN. control dial setting should be 10 (+2) db more
(1) Position azimuth Antenna AS-1292/
than setting recorded in (33) above.
TPN-8 by hand to any scan angle no greater than 12
(36) Disconnect radar test set and oscillo-
degrees (on either side of 0-degree), as indicated on
sopce.
azimuth scan protractor.
(37) Remove waveguide-to-coaxial adapter
(2) On vtvm, place RANGE switch to 10V
from elevation difference channel rotary coupler and
and SELECTOR switch to (-).
reconnect elevation difference channel wave- guide to
(3) On Remote Switching Control C-6989/
rotary coupler.
TPN-18, rotate MAX SENS control R4079 fully cw.
Observe vtvm indicates approximately -0.1 volt.
NOTE
(4) Rotate MAX SENS control ccw until
vtvm indication just starts to go more negative but does
Do not replace covers on Radar Receiver-
not go more negative. Disconnect vtvm.
Transmitter RT-818/TPN-18 until alignments and
(5) Calibrate radar test set for 0 dbm at 1.0-
adjustments are completed.
mw powr output level as described in (a) through (p)
below.
(a) Place POWER switch to ON and
3-35. Sensitivity Time Control Alignment
allow 10 minutes for warmup.
(b) Place rf power switch to POWER
SET.
a. Test Equipment Required.
(c) Set RF TUNING control to
(1) Multimeter ME-26A/ U(vtvm).
approximate operating frequency.
(2) Oscilloscope AN/USM-140B (oscillo-
(d) Place function switch to OFF.
scope.
(e) Adjust ZERO SET control for
(3) Radar Test Set AN/UPM-6 (radar test
ZERO SET indication on power meter.
set).
(f) Place function switch to INT FM.
b. Equipment Conditions and Connections.
(g) Rotate FM AMPLITUDE control
(1) Radar Set AN/TPN-18 turned on and
fully cw (100).
front and rear covers removed from Radar Receiver-
(h) Set ADD TO PWR METER control
Transmitter RT-818/TPN-18.
to 0 IDB (PWR SET).
(2) On master Control-Indicator C-6988/
(i) Rotate OUTPUT ATTEN. control
TPN-18 and Pulse Generator O-1333/TPN-18, SCAN
fully cw.
MODE switch placed to NORM, SCAN switch OFF, IF
GAIN-AZ
control
maximum
cw,
3-44
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