6-28
TURNING ON THE SCOPE
Before turning on the scope, make sure it is plugged into the proper power source. This may seem
obvious, but many technicians have turned all knobs on the front panel out of adjustment before they
noticed that the power cord was not plugged in. On some scopes, the POWER switch is part of the
INTEN (intensity) control. Turn or pull the knob until you hear a click or a panel light comes on (figure
6-31). Let the scope warm up for a few minutes so that voltages in all of the circuits become stabilized.
Figure 6-31.—Components to energize scope.
OBTAINING A PATTERN ON THE SCREEN
When adjusting a pattern onto the screen, adjust the INTEN (intensity) and FOCUS controls for a
bright, sharp line. If other control settings are such that a dot instead of a line appears, turn down the
intensity to prevent burning a hole in the screen coating. Because of the different speeds at which the
beam travels across the screen, brightness and sharpness will vary at various frequency settings. For this
reason, you may have to adjust the INTEN and FOCUS controls occasionally while taking readings.
NUMBER OF CYCLES ON THE SCREEN
Because distortion may exist at the beginning and end of a sweep, it is better to place two or three
cycles of the waveform on the screen instead of just one, as shown in figure 6-32.
