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ALIGNMENT
NOTE:
Use
an isolation transformer placed between the
power
line
and the
receiver to avoid hum and electrical
shocks.
If an isolation transformer is not available, con¬
nect the low side of the signal generator to B- through a . 1
mf capacitor.
1.
Connect a low range output meter across speaker voice
coil.
2.
Connect the low side of the signal generator through a
. I mf capacitor to B-.
3.
Set the signal generator for 400 cycle, 30% modulation.
4.
Turn the receiver volume control to maximum.
5.
Use a small fibre screwdriver for aligning the EF trans¬
formers.
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 1 for adjustment locations and the following
chart for procedure.
ALIGNMENT
CHART
DUMMY
GENERATOR
GENERATOR
GANG
ADJUST
STEP
ANTENNA
CONNECTION
FREQUENCY
SETTING
(See Fig. 1)
REMARKS
GNMENT
l.
. 1 mf
Grid of conv.
455 Kc
Fully
1, 2, 3 & 4
Adjust for maximum.
(pin 7,
12BE6)
open
(IF cores)
RF AL IGNMENT
2.
. I mf
Grid of conv.
1620 Kc
Fully
5 (Osc)
Adjust for maximum.
(pin 7,
12BE6)
open
3.
_
Radiation loop*
1400 Kc
Tune for
6 & 7(RF &
Adjust for maximum.
max
Ant trim)
^Connect generator output across 5" diameter, 5 turn loop and couple inductively to receiver loop.
Keep loops at least
12" apart.
©
TOP
©
BOT.
IF 455KC
DET. NO.698632313-0
FIGURE 1.
TUBE & TRIMMER LOCATIONS
3
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