Section II. OSCILLOSCOPE CHARACTERISTICS
General. The oscilloscope is used to visually display electrical impulses. Some oscilloscopes are designed
specifically for displaying only one trace. These oscilloscopes are classified as single trace oscilloscopes and consist
primarily of one vertical amplifier and one horizontal sweep generator connected to the deflection plates of the cathode-ray
tube (CRT). The versatility of an oscilloscope can be increased by providing for more than one vertical amplifier and one
horizontal sweep generator. A dual-trace oscilloscope contains this versatility by incorporating two plug in vertical amplifier
units and a dual time base plug-in unit that contains main triggering controls. These provide dual trace operation for the
comparison of two independent electrical impulses at the same time. When the recurring rate of a signal is so slow (a
pulse recurring once every 30 seconds) that it becomes impossible to adequately observe it on a conventional
oscilloscope, the storage oscilloscope should be used. The storage oscilloscope is designed to store the signal in its
memory and then display the signal on the CRT for viewings or photographing. In addition, the storage oscilloscope can
be operated as a conventional oscilloscope.
For the purpose of the discussion in this section, reference is made to an AN/USM 281C
Oscilloscope Controls (fig. 8-7). The controls for the oscilloscope are located in the front and rear panels.
The most commonly used controls will be discussed in this section. The more complex controls will not be covered, these
controls are for special applications. Refer to the operators manual of the particular oscilloscope you are using for their
Perform the initial control settings before turning the oscilloscope on for the first time. Once the
oscilloscope has been in use, it should not be necessary to repeat the initial control settings
unless the front controls have been completely maladjusted.
Initial Control Settings (fig. 8-8). Preposition the oscilloscope controls as follows:
Set INTENSITY knob (1) fully counterclockwise.
Turn FOCUS knob (2) to midrange.
Turn GRAT ILLUM knob (3) to midrange.
Be sure only one VERT MODE switch remains pressed in at a time.