Tektronix 502 series, Instruction Manual

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M A INTENANCE
PREVENTIVE MAINTENANCE
Air Filter
The Type 502 Oscilloscope is cooled by air
drawn into the instrument through a washable
filter constructed of adhesive coated aluminum
wool. If this filter is allowed to become dirty, it
will restrict the flow of air and may cause the
instrument to overheat. You should inspect, and
clean if necessary, the filter every three or four
months. If the filter is damaged, you should re­
place it as soon as possible to prevent dust be­
ing drawn into the instrument.
To remove the loose dirt in the filter, rap the
filter gently on a hard surface. Then wash the
filter briskly from the dirty side with hot water
or if necessary with hot, soapy water. After rins­
ing and drying thoroughly, coat the filter with
“ Handi-Koter” or “ Filtercoat", products of the
Research Products Corporation. These products
are generally available from air-conditioner sup­
pliers.
Fan M o to r
To protect the fan motor bearings, they should
be lubricated every three or four months with a
few drops of light machine oil.
Visual Inspection
You should visually inspect the entire oscillo­
scope every few months for possible circuit de­
fects. These defects may include loose or broken
connections, damaged binding posts, improperly
seated tubes, scorched wires or resistors, missing
tube shields, or broken terminal strips as well as
many others. For most of these troubles, the
remedy is apparent, but particular care must be
taken when scorched components are detected.
Scorched parts are often the result of other, less
apparent, defects in the circuit. Therefore, it is
essential that you determine the cause of over­
heating before replacing scorched parts in order
to prevent damage to the new components.
Recalibration
The Type 502 Oscilloscope is a stable instru­
ment, and will provide many hours of trouble-
free operation. To insure the reliability of meas­
urements obtained on the 502, we suggest that
you recalibrate the instrument after each 500
hours of operation (or every six months if used
intermittently).
A complete step-by-step pro­
cedure for recalibrating the instrument is pre­
sented in the Recalibration Procedure section of
this manual.
REMOVAL A N D REPLACEMENT OF PARTS
The procedures required for replacement of
most parts in the Type 502 are obvious. Detailed
instructions for their removal are therefore not
required. Other parts, however, can best be re­
moved if a definite procedure is followed. In­
structions for the removal of some of these parts
are contained in the following paragraphs. Be­
cause of the nature of the instrument, replace­
ment of certain parts will require that you recali­
brate portions of the oscilloscope in order to
insure the proper operation of this instrument.
Refer to Section 6 for recalibration procedures.
Removal of Panels
The panels of the Type 502 Oscilloscope are
held in place by small screwhead fasteners. To
remove the side panels, use a screwdriver to
rotate the fasteners approximately two turns
counterclockwise; then pull the upper portion of
the panels outward from the carrying handles.
To remove the bottom panel, lay the instrument
on its side, rotate the fasteners approximately
two turns counterclockwise, and pull off the
panel. In order to prevent damage to the finish
of the side panels, you should remove them be-
®
MAINTENANCE — TYPE 502
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