Equipment Description

Basic Oscilloscope
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horizontal sweep generator connected to a cathode ray tube (CRT).

The oscilloscope (AN/USM 281C) used in this subcourse provides dual

trace operation. A dual trace oscilloscope has two vertical

amplifiers and two horizontal sweep generators. This provides dual

trace operation for the comparison of two electrical impulses at

the same time.

Sometimes, the recurring signal rate is so slow that it becomes

impossible to observe it on a conventional oscilloscope. Then, a

storage oscilloscope must be used. The storage oscilloscope is

designed to store the signal in its memory and then display the

signal on the CRT. In addition, the storage oscilloscope can be

operated as a conventional oscilloscope.

EQUIPMENT DESCRIPTION

The AN/USM 281C oscilloscope (figure 1, on the next page) is a

lightweight, solid state instrument designed for general purpose

signal waveform measurements. It has single or dual trace

capabilities. The oscilloscope consists of the oscilloscope main

frame, two vertical amplifier plugin units, and the dual time base

plugin unit. These units are described in the following

paragraphs.

Main Frame

The main frame contains the CRT and power supply components and

provides three plugin compartments for the vertical amplifiers and

dual time base units. Of the three plugin compartments, the two

on the left are connected to the vertical deflection circuits. The

one on the right is connected to the horizontal deflection system.

Electronic switching between the vertical amplifiers allows a dual

trace vertical display.

Vertical Amplifier

The vertical amplifier is a wideband amplifier that provides

vertical deflection signals to the mainframe vertical amplifier

circuits. There are two vertical amplifier compartments in the

mainframe. This allows one amplifier to be used alone, for single

trace operation, or two amplifiers to be used for dual trace

operation.