Relative Susceptibility To Static Discharge; Damage - Tektronix 442 Service Manual

Table 5-2
RELATIVE SUSCEPTIBILITY TO
STATIC DISCHARGE
DAMAGE
Relative
Susceptibility
Semiconductor Classes Levels'
MOS or CMOS
microcircuits or discretes,
or linear microcircuits
with MOS inputs (Most Sensitive}
ECL
Schottky signal diodes
Schottky TTL
—_|—
High-frequency bipolar transistors
JFETs
Linear microcircuits
Low-power Shottky TTL
TTL (Least Sensitive)
* Voltage equivalent for levels:
1=100to500V 4=500V
2=200to 500 V 5 = 400
to 600 V 8 = 900 V
3 = 250 V 6 = 600 to 800 V
9 = 1200 V
7 = 400 to 1000 V(est.)
Obtaining Reptacement Parts
STANDARD PARTS. Most electrical and mechanical
parts can be obtained through your local Tektronix Field
Office or representative. However, you should be able to
obtain many of the standard electronic components from
a local commercial
source in your area. Before you
purchase or order a part from a source other than
Tektronix, Inc., please check the Replaceable Electrical
Parts list for the proper value, rating, tolerance and
description.
NOTE
Physical size and shape of a component may affect
instrument performance, particularly at high fre-
quencies. Always use direct-replacement com-
ponents, unless it is known that a substitute will not
degrade instrument performance.
SPECIAL PARTS. In addition to the standard elec-
tronic components, some special components are usedin
the 442, These components are manufactured or selected
by
Tektronix, Inc. to meet specific performance
re-
REV A MAY 1980
Maintenance—442 Service
quirements, or are manufactured for Tektronix, Inc. in
accordance with our specifications (see Cross |Index-
Manufacturers Code Number to Manufacturer in the
Replaceable Electrical Parts list for code numbers). Most
of the mechanical parts used in this instrument have been
manufactured by Tektronix, Inc. Order al! special parts
directly from your local Tektronix Field Office or represen-
tative.
ORDERING PARTS. When ordering replacement
parts from Tektronix, Inc., it is imperative that all of the
following information be included in order to ensure
receiving the proper parts.
1. Instrument type (include modification or option
numbers).
2. Instrument serial number.
3. A description of the part (if electrical, include the
circuit number).
4. Tektronix part number.
Soldering Techniques
To prevent electrical shock or damage to the 442,
always disconnect it from the power source and
allow approximately three minutes for the filter
capacitors in the power supply to discharge before
attempting
to solder in the circuitry or replace
components.
NOTE
Be sure you are familiar with soldering techniques
and parts replacement procedures before replacing
any electrical components in the 442.
Ordinary 60/40 solder and a 35- to 40-watt pencil-type
soldering iron can be used to accomplish the majority of
the soldering. If a higher wattage-rating soldering iron is
used on the etched circuit boards, excessive heat can
cause the etched circuit wiring to separate from the board
base material.
If it becomes necessary to solder in the general area of
any of the high-frequency contacts in the instrument,
clean the contacts immediately upon completion of the
soldering. Refer to the Switch Contacts paragraph in the
Preventive Maintenance part of this section for
recommended cleaners and procedures.
5-13