Operating instructions

University of Saskatchewan
Electrical Engineering Laboratory Equipment Manual
Tektronix 577 Curve Tracer
The 577 is the newest curve tracer in our inventory, and it is a little more
intimidating than its older counterparts, the 575s. However, its operation is just as
straightforward as it has the same basic controls as the 575s.
The power switch on this instrument is difficult to spot. It is located to the right of
the bottom corner of the display. The collector controls are found on the left side of the
panel, just underneath the display. To the right of them you will find the base step
controls. Just underneath of these lie the horizontal volts/div knob and the horizontal
and vertical position knobs.
The shelf at the bottom of the machine contains the transistor test pod on the left,
and the vertical current/div knob to the right. Above that is the base termination
selection control.
As with the 575s, the 577 has a toggle switch beneath the transistor test pod
which selects between the left or right connections on the pod. Keep the toggle switch
in the middle position while connecting/disconnecting any transistors/diodes, as
dangerous voltages can appear on those wires while a transistor or diode is being
tested.
To test an npn transistor, start by making sure that only the following buttons on
the front panel are pressed in:
 Step Family: REP
 Step Rate: NORM
 Step/Offset Polarity: NORM
 ZERO (found just to the right of the Step/Offset Polarity button)
 Display: NORM
 Filter: NORM
Make sure the settings below are selected. The settings for collector current/div,
volts/div and base step/offset amplitude are only suggested starting points; you may of
course alter them any way you wish.
Collector Sweep Controls:
 Variable Collector % knob set to ~ 40 – 50%
 Max Peak Volts: 25 V
 Max Peak Power: 0.6 W
 Series Resistor: 500
 Collector Supply Polarity: + (NPN side)
Step Generator Controls:
 Step/Offset Ampl: 10 A
 Number of Steps knob set to middle
 Offset Mult knob fully counterclockwise
Horizontal Controls:
 Horiz Volts/Div: 1 V/div (collector)
Vertical Controls: