Advertisement
SERVICE NOTES
TO REMOVE CHASSIS FROM CABINET:
1.
Remove the control knobs,
pointer knob and pointer;
these parts pull off.
2.
Remove
the two split plugs which hold the top of the
loop panel to the cabinet.
3. Remove the two chassis mounting screws, accessible
through the slots in the loop panel and slide the chas¬
sis from the cabinet.
ALIGNMENT
NOTE:
It is recommended that an isolation transformer be
placed between the power line and the receiver to avoid hum
and
electrical
shocks.
If
an isolation transformer is not
available, connect the low side df the signal generator
to E-
through a . 1 mf capacitor.
1.
Connect alow range output meter across the speaker
voice coil.
2.
Connect the low side of the signal generator to B-.
3.
Set the signal generator for 400 cycle,
30% modula¬
tion.
4.
Turn the receiver volume control to maximum.
5.
Use
a
small
fibre
screwdriver for aligning the IF
and diode transformers.
6.
As
stages
are
brought
into alignment,
reduce the
signal generator output to a level which produces less
than
. 40
volts
(. 05 watt)
across
the
voice coil to
avoid overloading the receiver.
7.
See Figure 2 for adjustment locations and the follow¬
ing chart for procedure.
ALIGNMENT
CHART
STEP
DUMMY
ANTENNA
GENERATOR
CONNECTION
GENERATOR
FREQUENCY
BAND
SWITCH
GANG
SET TO
ADJUST
REMARKS
IF
ALIGNMENT
1
.
1 mf
Rear stator of
tuning capaci¬
tor
SW BAND RF ALIGNMENT
2
.
400
ohms
SW Ant termi¬
nal
BC BAND RF ALIGNMENT
3.
4.
. 1 mf
None
Rear stator of
tuning capaci¬
tor
Radiation loop*
455 Kc
1 8. 1 me
1620 Kc
1400 Kc
SW
BC
BC
Gang
opened
Fully
opened
Fully
opened
Tune
for
maximum
1,
2,
3 &
4
5 & 6
Adjust for maximum.
Adjust for maximum.
Adjust for maximum.
Adjust for maximum.
* Connect generator output to 5" diameter,
3 turn loop and couple to receiver loop.
Keep loops at least 12" apart.
S.W.
B.C. LOOP
2
Advertisement
