Tektronix 1L40, Instruction Manual

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Operating Instructions— Type 1L40
6. The pulse repetition frequency is the reciprocal of the
measured time between pulses.
The expanded sweep feature of some plug-in oscillo­
scopes can be used to analyze or examine small portions
of a spectrum display. In some instances, because of signal
d rift or instability, it may be impractical to reduce the
dispersion to make this examination. It is more practical to
tune the desired portion of the display to screen center
and expand the sweep.
Fig. 2-22 shows an expanded display of a pulsed RF
signal. The null point can be easily examined.
High Resolution Capabilities
Figure 2-23 illustrates resolution capabilities of the Type
1L40. The DISPERSION is set to 1 kHz/cm and the RESOLU­
TION is uncoupled and turned fully counterclockwise. To
increase the apparent resolution turn the VIDEO FILTER
switch O N . Resolution is a function of the last IF amplifier
stage of the analyzer; therefore, the illustrations are typical
for any RF frequency with the local oscillator phase locked.
2-22