TM 11-5826-225-35
d. Connect the equipment as shown in figure
p. Slowly rotate the control unit TUNE con-
trol in a clockwise direction. The rotor plates
3-6. A schematic diagram of the tuning ca-
of capacitor Cl should rotate out of mesh with
pacitor test cable is shown in figure 35.
*
the stator plates.
e. Set the control unit range switch to 850
1750.
313. Local Oscillator Alignment
f. Adjust the control unit TUNE control so
a. Connect the equipment as shown in figure
that the hairline of the FREQUENCY indica-
22. It is necessary to connect the audio output
tor bisects the small circle located between
.
meter.
1,400 and 1,500 kc.
b. Loosen the locknuts on resistors R82,
g. Set the control unit switches as follows:
R90, and R131 (fig. 28) on the receiver, and
(1) Function switch to ANT.
adjust each resistor fully clockwise.
(2) BFO-OFF switch to OFF.
c. Adjust R136 fully clockwise (fig. 2-8),
k. Set the test set switches as follows:
a n d then adjust R136 five turns counterclock-
wise.
( 1 ) RECEIVER-CONTROL switch to
RECEIVER.
d. Set the switches on the control unit as
(2) DC POWER switch to ON.
follows :
(1) BFO-OFF switch to BFO.
i. Rock the control unit TUNE control back
(2) Function switch to ANT.
and forth across the small circle on the FRE-
QUENCY dial and adjust it for a null (mini-
e. Set the switches on the test set as follows:
mum ) indication on the vtvm.
(1) DC POWER switch to ON.
j. Manually rotate the shaft which drives
( 2 ) RECEIVER-CONTROL switch to
capacitor Cl (fig. 2-8) until the rotor plates
RECEIVER.
of section ClE (nearest the gear train) are
(3) GONIO DRIVE switch to ON.
fully meshed with the stator plates. The plates
must be exactly meshed, with the tops of the
f . Set the 150 PF-270PF switch on the sense
rotor plates exactly in line with the tops of
antenna adapter to 150 PF.
the stator plates.
g. Set the range switch on the control unit
to 190400, and adjust the TUNE control on
k. Tighten the setscrews (68, fig. 5-16)
on collar (69). Be careful that the split gears
the control unit for 390 kc on the FREQUEN-
on the capacitor shaft do not become un-
CY indicator.
meshed and lose- their spring loading.
h. Set the frequency of the signal generator
CAUTION
to 390 kc, plus or minus 0.1 kc.
After tightening the setscrews (k
i . Modulate the signal generator output 30.
a b o v e ) , do not move the control
percent with 400 cps. Maintain this modulation
TUNE control until the tuning capac-
throughout the procedures.
itor test jig has been removed.
j. Adjust C36 (fig. 216 or 216.1) until a
l. Throw the test set DC POWER switch
zero beat is heard in the headset.
to OFF.
k. Adjust the TUNE control on the control
m. Disconnect the vtvm.
unit for 200 kc on the FREQUENCY indicator,
n . Remove the tuning capacitor test jig
from the equipment setup, and connect P2 of
1. Set the signal generator to 200 kc, plus
or minus 0.1 kc.
the test set directly to J3 of the receiver.
m. Listen for a zero beat in the headset
o. Throw the test set DC POWER switch
to ON.
while adjusting the TUNE control on the con-
3-22 Change 1
Previous Page
