TB 11-6625-2747-50
Figure 2. Rear interior view.
b. Adjustments.
maximum deflection on receiver (A7) NULL meter.
(1) Remove TI from case.
(5) Phase lock and level signal source and fine
(2) Adjust R85 (fig. 2) for a pulse width less
tune for an oscilloscope display of 30 mHz 25 kHz
than 0.5 microseconds wide as indicated on the
(difference of local and reference oscillator frequencies).
oscilloscope.(R)
(6) Adjust RF power output of signal source
(3) Adjust PULSE WIDTH control of TI for a 10
utilizing level set attenuator (B2) number 2 for 0.9 ma as
microsecond wide pulse as indicated on the
indicated on CRYSTAL CURRENT meter of receiver.
oscilloscope.
(7) Adjust REFERENCE ATTENUATOR control
(4) Loosen knob setscrews and slip PULSE
of receiver for 0 db as indicated by ATTENUATION-DB
WIDTH control so that 10 is located under panel index
digital readout of receiver.
marker.
Tighten setscrews.
(R) Repeat the
(8) Turn TI MOD SELECTOR switch to OFF.
performance check.
14. Attenuator. a. Performance Check.
(9) Turn POWER LEVEL-OSC. OFF control of
receiver counterclockwise to OSC. OFF.
(1) Connect equipment as shown in figure 3.
CAUTION
(10) Adjust NOISE BALANCE control of receiver
Since
ferrous
materials
may
for zero as indicated on NULL meter.
NOTE
permanently damage magnetic fields
Do not readjust NOISE BALANCE
of the BWO tubes used in the RF
control for the remainder of this
head
assembly,
keep
ferrous
procedure.
materials away from BWO tubes and
use only nonferrous tools when
(11) Turn TI MOD SELECTOR to CW and
working near BWO tubes.
stabilize at frequency and power output as in (2) and (3)
above.
(2) Adjust TI controls for a CW output frequency
(12) Turn POWER LEVEL-OSC OFF control of
of 12.75 kmc.
receiver to POWER LEVEL.
(3) Adjust TI OUTPUT ATTEN DBM control to 0
(13) Adjust level set attenuator number 1 for null
db.
(zero reference) as indicated on NULL meter of receiver.
(4) Adjust controls of signal source (A) for a CW
output frequency of approximately 12.75 kmc. Coarse
8
