Tektronix 455, Instruction Manual, Page: 163 / 246

Section 9 -4 5 5 /A 2 /B 2
DIAGRAMS AND CIRCUIT BOARD ILLUSTRATIONS
Symbols and Reference Designators
Electrical components shown on the diagrams are in the follow ing units unless noted otherwise:
Capacitors = Values one or greater are in picofarads (pF).
Values less than one are in microfarads (pF).
Resistors = Ohms (£2).
Graphic symbols and class designation letters are based on ANSI Standard V32.2-1975.
Logic symbology is based on ANSI Y32.14-1973 in terms o f positive logic. Logic symbols depict the logic
function performed and may d iffe r from the manufacturer's data.
The overline on a signal name indicates that the signal performs its intended function when it goes to the low state.
Abbreviations are based on ANSI Y 1 .1-1972.
Other ANSI standards that are used in the preparation o f diagrams by T ektronix, Inc. are:
Y14.15, 1966 Drafting Practices.
Y14.2, 1973 Line Conventions and Lettering.
Y 1 0 .5 ,1968 Letter Symbols fo r Quantities Used in Electrical Science and
Electrical Engineering.
The follow ing prefix letters are used as reference designators to identify components or assemblies on the diagrams.
A Assembly, separable or repairable
H
Heat dissipating device (heat sink,
S
Switch or contactor
(circuit board, etc) heat radiator, etc)
T
T ransformer
AT
Attenuator, fixed or variable HR Heater
TC Thermocouple
B Motor HY Hybrid circuit
TP
Test point
BT
Battery J
Connector, stationary portion
U Assembly, inseparable or non-repairable
C
Capacitor, fixed or variable K Relay
(integrated circuit, etc.)
CB
Circuit breaker
L Inductor, fixed or variable
V
Electron tube
CR Diode, signal or rectifier M Meter
VR
Voltage regulator (zener diode, etc.)
DL Delay line P
Connector, movable portion
W
Wirestrap or cable
DS Indicating device (lamp) Q
Transistor or silicon-controlled
Y
Crystal
E Spark Gap, Ferrite bead
rectifier
2
Phase shifter
F Fuse R
Resistor, fixed or variable
FL
Filter
RT Thermistor
,— Plug to E.C. Board
The follow ing special symbols may appear on the diagrams: S
Strap or Link
Cam Switch
Closure Chart
(Dot indicates
switch closure)
SEL Value Selected
at Factory
Test Voltage
Internal
Screwdriver
Adjustment
Assembly Number
Board Name
V E R T IC A L A M P L IF IE R ^ * * .
I Box I Identifies Panel
Controls, Connectors and
Indicators
___ Modified Component—See
In i s] < Parts List (Depicted in grey,
5 0 k or with grey outline)
Plug Index
Refer to Waveform
Refer to Diagram Number
Coaxial Connector
Shielding
Heat Sink
Decoupled or Filtered
Voltage
Etched Circuit Board
Outlined in Black
Schematic Name
and Number
REV. B NOV 1977