9–1
WFM 300A
Section 9
Diagrams/Circuit Board Illustrations
Symbols
Graphic symbols and class designation letters are based on ANSI Standard Y32.2–1975.
Logic symbology is based on ANSI Y32.14–1973 in terms of positive logic. Logic
symbols depict the logic function performed and may differ from the manufacturer’s data.
Overline, parenthesis, or leading slash indicate a low asserting state.
Example: ID CONTROL, (ID CONTROL), or /ID CONTROL.
Abbreviations are based on ANSI Y1.1–1972.
Other ANSI standards that are used in the preparation of diagrams by Tektronix, Inc. are:
Y14.15, 1966 -- Drafting Practices.
Y14.2, 1973 -- Line Conventions and Lettering.
Y10.5, 1968 -- Letter Symbols for Quantities Used in Electrical Science and
Electrical Engineering.
American National Standard Institute
1430 Broadway, New York, New York 10018
Component Values
Electrical components shown on the diagrams are in the following units unless noted
otherwise:
Capacitors: Values one or greater are in picofarads (pF).
Values less than one are in microfarads (mF).
Resistors = Ohms (W).
The following information and special symbols may appear in this manual.
Assembly Numbers
Each assembly in the instrument is assigned an assembly number (e.g., A20). The
assembly number appears on the diagram (in circuit board outline), circuit board illustra-
tion title, and lookup table for the schematic diagram.
The Replaceable Electrical Parts List is arranged by assembly number in numerical
sequence; the components are listed by component number. Example:
Chassis–mounted components
have no Assembly No. prefix.
See end of Replaceable Electrical
Parts List
Assembly
Number
Component Number
Schematic Circuit
Number
Grid Coordinates
The schematic diagram and circuit board component location illustration have grids. A
lookup table with the grid coordinates is provided for ease of locating the component.
Only the components illustrated on the facing diagram are listed in the lookup table.
When more than one schematic diagram is used to illustrate the circuitry on a circuit
board, the circuit board illustration will only appear opposite the first diagram; the lookup
table will list the diagram number of other diagrams that the other circuitry appears on.
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