TM 11-5840-281-35/1
(3) Test equipment connected as shown in
NOTE
c. Procedure.
Do not make further adjustments with CHANNEL A
(1) Calibrate radar test set for 0 dbm at 1.0
SENSITIVITY or CHANNEL A SENSITIVITY VER-
mw power output level as follows:
NIER controls. They are adjusted for 0.2 volt-per
(a) Place POWER switch to ON and
centimeter deflection, using 10:1 voltage divider
allow 10 minutes for warmup.
vertical input test prod.
(b) Place rf power switch to POWER
SET.
(8) On master Control-Indicator C-6988/
(c) Set RF TUNING control to
TPN-18, place TRANSMITTER switch to NAR- ROW but
approximate operating frequency.
not through NARROW to HV ON. Observe that HV ON
(d) Place function switch to OFF.
indicator is extinguished.
(e) Adjust ZERO SET control for
(9) On Intermediate Frequency Amplifier
ZERO SET indication on power meter.
AM3339/TPN-8, adjust WIDE BAND IF GAIN ADJ R336
(f) Place function switch to INT FM.
until noise amplitude displayed (above baseline) on
(g) Rotate FM AMPLITUDE control
oscilloscope is 1 cm (0.2 volt).
fully cw (100).
(10) On master Control-Indicator C-6988/
(h) Set ADD TO PWR. METER
TPN-18, place TRANSMITTER switch to OFF then to
control to 0 DB (PWR SET).
WIDE but not through WIDE to HV ON.
(i) Rotate OUTPUT ATTEN. control
Observe that HV ON indicator is extinguished.
fully cw.
(11) On Intermediate Frequency Amplifier
(j) Adjust RF TRIMMER until indication is
AM-3339/TPN-8, adjust NARROW BAND IF GAIN ADJ
obtained on power meter.
R326 until noise amplitude displayed on oscilloscope is 1
(k) Place function switch to CW.
cm (0.2 volt).
(I) Adjust RF TRIMMER and
(12) Disconnect oscilloscope.
REFLECTOR controls for maximum indication on power
meter. Maintain power meter indication below half-scale
NOTE
by adjusting OUTPUT ATTEN. control ccw.
(m) Adjust OUTPUT ATTEN. control
Do not replace covers on Radar Receiver-
until power meter indiiates 0 dbm (PWR SET).
Transmitter RT-818/TPN-18 until alignments and
(n) Rotate OUTPUT ATTEN. control
adjustments are completed.
cursor until cursor index mark aligns with red mark
(PWR SET) on OUTPUT ATTEN. control dial.
3-33. Video Amplifier Alignment
(o) Alternately place function switch to
OFF and CW. Power meter indication should be ZERO
a. Test Equipment Required.
SET in OFF, and 0 DBM (PWR SET) in CW. If
(1) Oscilloscope AN/USM-140B (oscillo-
necessary, readjust ZERO SET control (in OFF position)
scope).
and OUTPUT ATTEN. control and cursor (in CW
(2) Radar Test Set AN/UPM-6 (radar test
position) as required.
set).
b. Equipment Conditions and Connections.
NOTE
(1) Radar Set AN/TPN-18 turned on and
front and rear covers of Radar Receiver-Transmitter RT-
The radar test set calibration must be checked
818/TPN-18 removed for access to controls.
by performing steps (k) through (o) above, if
(2) On master Control-Indicator C-6988/
frequency of radar test set is changed after initial
TPN-18 and Pulse Generator O-1333/TPN-18, place
SCAN MODE switch to SEARCH, SCAN switch OFF,
TRANSMITTER switch placed to OFF, then to WIDE, HV
(2) On radar test set, place controls to
ON indicator extinguished, STC switch OFF, FTC switch
positions indicated in (a) through (e) below.
OFF, and IF GAIN-AZ control fully cw.
3-40
Previous Page
