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1.
G E N E R A L.
The Type SSB-1 communications equip
ment should maintain its correct factory
adjustment over a reasonably long period
of time.
Causes of trouble and methods of
checking and adjustment are outlined in the
following paragraphs.
T U B E S.
2.
V A C U U M
Breakdown or faulty operation of radio
communication equipment may usually be
attributed to defective vacuum tubes. Locate
the chassis in which faulty operation occurs,
by use of the troubleshooting procedure
given below, and attempt to locate the tube
that is defective.
If it is impossible to
localize the defective stage, change all tubes,
one at a time, and either check in a tube
tester or substitute a new tube.
complement is listed in the technical sum
mary of Section I, illustrated in figures 4 and
14; tube locations are shown in figure 15.
3.
T R
U B L E
S H
0
In the event of equipment breakdown, it is
first necessary to sectionalize the trouble
to either the power supply chassis, which
includes power supply and audio circuits ,
or the transmitter-receiver chassis, which
includes the oscillator, transmitter and re
ceiver circuits.
Secondly, it is necessary
to localize the trouble to a particular stage.
The following procedure not only will assist
in locating the trouble source but will also
act as an overall check of optimum system
performance after repairs have been made.
a. TEST EQUIPMENT - The following test
eqUipment is required to check and align the
SSB-1.
(1) Vacuum Tube Voltmeter with R. F.
probe
(2)
Calibrated Signal Generator
Oscilloscope
(3)
(4)
0-250 ma D.C. Milliammeter
Calibrated Audio Oscillator
���
Dummy Antenna: Any 75 watt non-
y
MAINTENANCE
The tube
T I N G.
0 0
27
inductive resistor with a resistance between
10 and 80 ohms in series with a transmitting
type mica capacitor of at least 300 uuf.
b. TEST PROCE DURE -Performance of
these tests presupposes that the technician
is familiar with the operating procedures
given in Section IV. Follow the step-by-step
procedure, checking that panel lamps light,
an audio response is obtained at the receiver
output and the PEAK MO DULATIONINDICA
TOR indicates modulation of the transmitted
output.
c. TROUBLE SHOOTING INFORMATION
The following photographs and charts are
included in this book to facilitate the local
ization of a trouble source within the equip
ment.
Figure 15. Tube Location Diagram
Figure 16. Power Supply, Top View
Figure 17. Power Supply, Bottom View
Figure 18. Speech Clipper, Internal View
Figure 19. Remote Desk Set
Figure 20. Transmitter-Receiver, Top
View
Figure 21.
Transmitter-Receiver, Bot
tom View
Figure 22.
Color Codes
Figure 28.
Power Supply Schematic
Figure 29.
Transmitter-Receiver Sche
matic
Table 2.
Tube Socket Voltages
Table 3.
Terminal Boards, Voltage and
Resistance Readings
d. O P E R A T I O NAL AND
CHECK.- Perform a complete check of the
equipment under various operating condi
tions.
The receiver may be checked using
transmission from another single-sideband
station or using an accurately calibrated
signal generator adjusted to a frequency in
the sideband range for the channel being
checked.
The transmitter may be checked
using either a single-sideband receiver or
an AM receiver with a beat-frequency os
cillator to listen to the signal.
faulty operation or improper signal and pro
ceed to find the tr..ouble and correct if before
making final adjustments.
VOLTAGE
Note any
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