Tektronix TYPE L, Инструкция по эксплуатации

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O INI 4
M A I N T E N A N C E
P R E V E N T IV E M A IN T E N A N C E
The L Unit is a stable instrument, and w ill
require complete calibration very infrequently.
H ow ever, to be certain that the unit is operat­
ing properly at all tim es, the calibration of
the unit should be checked after each 500-hour
period of operation (o r every six months if
the unit is used intermittently). A complete
step-by-step procedure fo r calibrating the unit
and checking its operation is given in the
Calibration section of this manual.
V isu al Inspection
Many potential and existent troubles can be
detected by a visual inspection of the unit.
F o r this reason, a complete visual check should
be perform ed every time the unit is inoperative,
needs repairs, o r needs recalibration. Apparent
defects may include loose o r broken connections,
damaged connectors, im properly seated tubes,
scorched o r burned parts, and broken terminal
strips.
The remedy fo r these troubles is
readily apparent except in the case of heat-
damaged parts. Damage to parts due to heat
is often the result of other less apparent
troubles in the unit. It is essential that the
cause of overheating be found before replacing
the damaged parts.
C O M P O N E N T R E P L A C E M E N T
The procedures fo r replacing most parts
in the L Unit are obvious and detailed instruc­
tions are not required. In some cases, additional
information w ill aid in the replacement of
parts. This information is given in the follo w ­
ing paragraphs. Because of the nature of the
instrument, replacement of certain parts w ill
require that portions of the instrument be
calibrated fo r proper operation. Refer to the
Calibration section of this manual fo r the
procedures required.
Switches
If a switch is found to be defective and
needs to be repaired or replaced, use normal
care in unsoldering and disconnecting leads
from the terminals.
Single wafers on wafer-type switches are
not normally replaced. If a wafer is defective,
the entire switch should be replaced. The
VOLTS/CM switch may be ordered from the
factory either unwired or with parts wired
in place, as desired. Refer to the Parts List
to find the wired and unwired part numbers.
When soldering leads to a wafer-type switch,
do not let solder flow around and beyond the
rivet on the switch terminal. The spring tension
of the switch contact may be destroyed by
excess solder.
Occasionally, wafer switches become erratic
because of accumulated dust or other foreign
m aterial on the contacts. This condition may
be corrected by using one of the cleaning-
lubricating products available from electronics
parts distributors. Be sure to leave a thin
layer of conductive lubricant on the contacts,
but no excess. Remove any excess lubricant
with a moderate jet of compressed air.
Ceram ic T erm inal Strips
Two distinct types of ceram ic strips have
been used in Tektronix instruments. The earlier
type mounted on the chassis by means of
#2-56 bolts and nuts. The later type is mounted
with snap-in plastic fittings. Both styles are
shown in Figure 4-1.
When replacing a ceram ic terminal strip
o f the type which bolts onto the chassis, first
unsolder all connections, then unscrew the
terminal bolt nuts on the reverse side of the
AA Maintenance - Type L Plug-In
4-1