TM 9-6625-1753-14
C2
Table 2-2. Dual Trace Plug-In, Controls and Indicators (Fig. 2-6)
CHAPTER 2
OPERATING INSTRUCTIONS
Key
Control, Indicator or Connector
Function
2
Beam position indicators
Arrow next to glowing lamp indicates the direction
that trace is deflected (off the CRT screen).
4,
ATTEN BAL control
Screwdriver adjustment to prevent displacement of
Section I. SERVICE UPON RECEIPT OF MATERIEL
43
the trace when VARIABLE and VOLTS/DIV
2-1. General
controls are activated.
5,
POSITION control
Positions the trace up or down on the CRT screen.
a. When a new or reconditioned oscilloscope is first received by the using organization, it is the responsibility of the
44
person-in-charge to determine whether the materiel is complete, and if it is in satisfactory condition in service. The service
6,
DC BAL control
Screwdriver adjustment to prevent displacement of
procedures of a general nature are listed in paragraph 2-2.
42
the trace when the VARIABLE control is activated.
7
MODE switch
Selects the following dual-trace modes:
b. Make a record of all deficiencies found so that they may be either remedied by the using organization or referred to
A: Only channel A signal is displayed.
B: Only channel B signal is displayed.
the direct support and general support maintenance personnel.
ALT: Both channel A and Channel B signals
are displayed on alternate sweeps.
2-2. General Services
CHOP: Both channel A and channel B signals
are displayed. Switching from channel A to
a. Carefully note all markings and/or tags attached to the materiel, since they may contain information relating to
channel B is at an arbitrary rate (approximately
operation and maintenance.
60 kc). This mode of operation is used when a
single transient is to be observed at two points
b. Refer to the appendix for applicable forms, records, and reports for inspection. Inspect the records of maintenance,
in a circuit, and also for slow sweeps when the
previously performed on the materiel to determine its maintenance background. A record of progressive repairs may indicate
ALT mode has too much flicker.
A + B: Both channel A and B signals displayed at
a defective unit, while a record of regular preventive maintenance may indicate a unit in excellent condition.
the same time. The overall display is the
algebraic sum of both signals.
Section II. CONTROLS AND INDICATORS
1,
VOLTS/DIV switch
Selects accurately calibrated vertical deflection sensi-
45
tivities of 0.005, 0.01,0.02, 0.05, 0.1,0.2, 0.5,
2-3. General
1, 2, 5, or 10 volts per division when the
VARIABLE control is in the CAL position.
This section contains tables 2-1 through 2-3 which list the various controls and indicators of the oscilloscope, and describe the
3,
VARIABLE control
Provides uncalibrated variable vertical deflection sen-
type and function of each.
46
sitivities between settings of the VOLTS/DIV
switch (up to 25 volts/div for a setting of 10),
when turned counterclockwise from the CAL
2-4. Main Frame, Controls and Indicators
position.
49,
NORM-INVERT switch
Selects the polarity of the displayed waveform. Pro-
Table 2-1. Main Frame, Controls and Indicators (Fig. 2-6)
52
vides ac or dc coupling of the input signal in the
NORM or INVERT position.
NORM: Displayed waveform has the same polarity
Key
Control, Indicator or Connector
Function
as the input signal.
INVERT: Displayed waveform has the opposite
11
INTENSITY control
Regulates brightness of trace on CRT screen.
polarity of the input signal (positive-going input
signal is displayed as a negative-going signal).
9
ASTIG control
Adjusts shape of spot on CRT screen.
GND: Grounds the amplifier input circuit.
10
BEAM ROTATE control
Rotates the CRT electron beam to compensate for
the EARTH'S magnetic effect on trace alinement.
50,
GAIN ADJ control
Screwdriver adjustment for setting the calibrated
39
FOCUS control
Adjust sharpness of trace on CRT screen.
51
vertical deflection sensitivity.
38
SCALE ILLUM control and power switch
Dimmer for scale lamps and turns on power to
2-5.1. Dual Trace Plug-In 79-02A, Controls, Indicators, and Connectors
2-5. Dual Trace Plug-In, Controls and Indicators
Table 2-2.1. Dual Trace Plug-In 79-02A, Controls, Indicators, and Connectors
Note. Since the controls and indicators for channel A and B are identical, only the controls for channel A are
described.
Key
Control, Indicator or Connector
Function
72
BEAM FINDER switch
A spring-loaded switch. If the beam is off the screen,
the switch may be depressed to locate the beam.
62
CH2 OUT connector
The channel 2 preamplifier output is available at this
BNC connector, connected through a 5,000 ohm re-
sistor.
2-1
