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Emerson Radio
Proper adjustment of the H O R IZ O N T A L and
V E R T IC A L L IN E A R IT Y controls, and the SIZE
controls should result in test patterns in which the
circles are round and the wedges are linear and equal.
The test pattern circles should be concentric with the
curved sides of the mask.
Figure 5-4— Rear Deflection Adjustments,
*For chassis not equipped with wobble plate and
centering lever.
6.
ALIGNMENT TEST EQUIPMENT — Proper
servicing and alignment of Chassis 120110B and 120-
113B requires the equipment indicated.
a.
SW EEP G E N E R A T O R :
1) Frequency ranges of 18 to 30 MC., 50 to 90
MC., and 170 to 225 MC.
. 2) Sweep width variable to 10 MC.
3) Output of at least 0.1 volt, with an attenuator
for adjustment of output.
4) Constant output over sweep width, with flat
output on all ranges and at all attenuator posi
tions.
5) Output impedance of 300 ohms, for r-f align
ment, or matching network. See figure 5-5.
b.
M AR K E R G E N E R A TO R :
1) Frequency ranges of 4 to 30 MC. and 50 to
225 MC., for i-f and r-f alignment. The mark
er generator must provide an accurate (crystal
calibrated) frequency of 4.5 MC. for audio i-f
alignment, and accurate frequencies from 21.25
MC., to 25.75 MC., for video i-f alignment.
The required r-f requencies from 50 to 225
MC., as tabulated below, may be provided by
a calibrated signal generator or a heterodyne
frequency meter with crystal calibrator.
2) Output of at least 0.1 volt, with an attenuator
for adjustment of output.
GENERATOR FREQUENCIES: (Table IV ).
VID E O
C H AN N EL
CARRIER
2
3
4
5
6
7
8
9
10
11
12
13
A U D IO
CARRIER
M C
MC.
59.75
55.25
65.75
61.25
71.75
67.25
81.75
77.25
87.75
83.25
179.75
175.25
181.25
185.75
187.25
191.75
197.75
193.25
199.25
203.75
205.25
209.75
215.75
213.25
Scanned by mbear2k - Jan 20121/17
TO
GEN
-------- 4------ V V \ /------------ -
USE CARBON RESISTORS ONLY.
Figure 5-5— Generator Matching Network
VACU U M -TU BE V O L T M E T E R :
1) A diode .probe for high-frequency measure
ments is desirable.
2) High input impedance with provision for low-
voltage measurement (three or five volt scale).
d.
O SCILLO SCO PE:
1) Vertical input should be provided with a cali
brated attenuator and low-capacity probe.
2) Flat vertical amplifier frequency response, with
good low frequency response.
3) Adequate vertical sensitivity.
e.
SCOPE D E T E C T O R : Required for alignment of
over-coupled first i-f T l. See figure 5-6.
Figure 5-6— Scope Detector Network
7.
ALIGNMENT—
a.
AU D IO I-F A L IG N M E N T :
1) Disconnect the antenna and remove the chas
sis from the cabinet. Use an adaptor line cord
to operate the receiver.
2) Set the C O N TR A ST control at the center of
rotation and retain at this setting for all i-f
adjustments.
3) The waveforms shown in the response curves
may be inverted depending on the number of
amplifying stages in the vertical amplifier of
the scope being used.
4) When the marker signal is coupled in parallel
with the sweep generator, the signal should be
unmodulated and attenuated so that only a
small pip is visible.
controlled marker generator.
5) Connect the sync sweep voltage from the sweep
signal generator to the horizontal input of the
scope for horizonal deflection. ^
6) Refer to figure 5-7 for location of alignment
points; figure 5-3 for the schematic diagram.
7) Set the receiver to Channel 3.
955282
120
- A / W
TO
50
R E C E IV E R
120
TO TEST POINTS
IN RECEIVER
(KEEP LEADS SHORT)
Use an accurate, crystal-
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