Ntensity Modulation - Tektronix 545A Instruction Manual

portion of the display you wish to expand to the center of
the graticule, then placing the 5X MAGNIFIER switch in
the ON position. When the 5X MAGNIFIER switch is at
ON, the 5X MAGNIFIER lamp lights to indicate the mag ­
nifier is on. Any portion of the original unmagnified display
can then be observed by rotating the HORIZONTAL PO I ­
TION controls. The sweep magnifier can be used with either
time base unit.
In magnified sweep operation, the sweep speed indicated
by the position of the TIME/CM control is divided by 5 to
obtain the actual time required for the spot to move one
centimeter. For example, if the TIME/CM control is set at
5 MILLI EC, the actual time per centimeter is 5 milliseconds
divided by 5, or 1 millisecond per centimeter. The actual
time per centimeter must be used for all measurements of
time.
Amplitude Calibrator
The amplitude calibrator provides a convenient source
of square waves of known amplitude at a frequency of
approximately 1 kc. The square waves are used primarily
to adjust probes and to verify the calibration of the
vertical-deflection system of the oscilloscope and plug-in
unit.
Calibrator square-waves are adjustable from .2 milli ­
volts, peak-to-peak, to 100 volts, peak-to-peak, in 18 steps.
The amplitude is controlled by the setting of the AMPLITUDE
CALIBRATOR switch and is accurate within 3% of the
AMPLITUDE CALIBRATOR switch setting when the output
is connected to a high impedance load.
Operating
Dual-Trace Displays
The Type CA Plug-In Unit allows you to obtain two
separate traces on the face of the crt. This permits you to
display two functions simultaneously.
for operating the Type CA Unit in conjunction with the
Type 545A Oscilloscope are contained in the Instruction
Manual for the Type CA Unit.
When you are using the Type CA Unit in the chopped
mode to obtain a dual-trace presentation, switching tran ­
sients will be displayed on the screen. You can eliminate
these switching transients by placing the CRT CATHODE
ELECTOR switch on the rear of the instrument in the DUAL ­
TRACE CHOPPED BLANKING position.

ntensity Modulation

The crt display of the Type 545A Oscilloscope can be
intensity modulated by an external signal to display addi ­
tional information. This
grounding bar from the EXTERNAL CRT CATHODE con
nector at the rear of the instrument and connecting the
external signal to this terminal. The CRT CATHODE
TOR switch must be in the EXTERNAL CRT CATHODE posi ­
tion.
When you wish to make very accurate time measure ­
ments from the crt display, you can intensity modulate the
beam with time markers and make your measurements di ­
rectly from the time markers presented on the screen. A
positive signal of approximately 25 volts is required to
cut off the beam from normal intensity.
nstructions — Type 545A
Detailed instructions
is done by disconnecting
2-13
the
ELEC ­