Operating Information; Introduction; Preliminary; Controls - Tektronix 177 Instruction Manual

Section 2-177 Service
OPERATING INFORMATION
Introduction
The 177 Test Fixture operates with a Tektronix 577
Curve Tracer and the D1 or D2 Display Unit as a system.
This section of the manual gives a brief functional
description of the front·panel controls of the 177. See the
577 -177 -D 1 or D2 Operators Manual for a complete
operating procedure.
Preliminary
For initial preparation, refer to the Operating Instruc-
tions section of the 577-177-D1 or D2 Operators Manual.
The Operators Manual contains operating instructions, as
well as general and specific application information.
Controls
This is a brief description of the functions of the
front-panel controls. More detailed information is given in
the Operators Manual.
EMITTER GROUNDED MODE (Emitter terminal is
grounded; Base terminal is switched as follows):
®
BASE TERM
STEP GEN
Applies step generator output to the base connec·
tions of the test fixture.
OPEN (OR EXT)
Disconnects the base terminal from the step
generator output and connects base terminal to
the front-panel EXT BASE OR EM IT INPUT
Connector.
SHORT
Disconnects the base terminal from the step
generator output and grounds the base term inal.
BASE GROUNDED MODE (Base terminal is grounded,
step generator polarity is inverted, and the em itter term inal
is switched as follows):
EM ITTER TERM
OPEN (OR EXT)
Disconnects the emitter term inal from the step
generator output and connects the emitter ter-
minal to the front-panel EXT BASE OR EM IT
INPUT Connector.
STEP GEN
Applies step generator output to the em itter
terminal.
EMITTER-BASE BREAKDOWN
Grounds the base term inal and applies the collector
sweep voltage to the emitter terminal. Only the collector·
voltage ranges that are not interlocked are available.
STEP GEN OUTPUT Connector
Provides external access to the step generator output.
EXT BASE OR EM IT IN Connector
Provides external access to the base or em itter term ina Is,
depending on the position of the Terminal Selector switch.
GROUND
Provides for external ground connection.
LEFT-RIGHT Switch
Three position toggle switch for applying test signals to
either the left or right set of terminal connectors. The
center position disconnects all terminals except the emitter
term ina Is. The em itter term inals are always connected
together and are connected to either ground, to the step
generator, or to the collector sweep depending on the
position of the Terminal Selector switch.
Test Adapter Terminal Jacks
Two sets of five recessed jacks accepting various adapters
for testing various sem icond uctor devices.
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