Tektronix 585 - Page 50

Maintenance — Type 585
Fig. 5-8. Two types of ceramic strip mountings.
Type 585, replacement of certain parts will require that
you recalibrate portions of the oscilloscope in order to
insure the proper operation of the instrument. Refer to the
Calibration Procedure section of this manual when replacing
precision or adjustable parts.
Removal of Panels
The panels of the Type 585 Oscilloscope are held in
place by coin slotted fasteners. To remove the side panels,
use a screwdriver or coin to rotate the fasteners two or
three turns counterclockwise; then pull the upper portion
of the panels outward from the carrying handles. To re 
move the bottom panel, lay the instrument on its side,
rotate the fasteners two or three turns counterclockwise,
and pull off the panel. Panels are replaced by reversing
the order of their removal.
Replacement of the Cathode-Ray Tube
CAUTION: When replacing a cathode-ray tube,
wear both a plastic face guard and leather gloves.
These items will protect the operator in case of an
implosion and flying glass.
To remove the cathode-ray tube, first carefully remove all
leads connected to the neck of the tube. Loosen the mount 
ing clamp located near the socket, then disconnect the tube
socket.
Carefully slip the new c rt in place past the in-place high
voltage connector. Be careful, since if a neck pin strikes
a sharp edge, the seal can be broken and a new c rt re 
quired. When the c rt is in place, the leads can be properly
connected to the neck pins of the tube by using the color
code information provided on the tube shield. Place the
graticule over the c rt face with the scribed lines on the
inside, toward the c rt face. Then place the four rubber
washers (if provided) over the four graticule mounting
studs. Replace the bezel and secure it in place with the
four knurled nuts. After replacement of the c rt, it may be
necessary for you to recalibrate certain portions of the
oscilloscope. Special attention should be given to calibration
of the sweep, the vertical deflection factor, and the GEOM 
ETRY control. Horizontal trace alignment is easily accom 
plished by adjustment of the red knob located under the
c rt socket, immediately under V 1 284. Be careful not to
rotate the c rt far enough to short any neck connections
to ground.
In the graticule replacement procedure above, if you use
a Tektronix camera mounting bezel, do not replace the
four rubber washers between it and the graticule.
Replacement of Switches
Methods for removal of defective switches are, for the
most part, obvious and only a normal amount of care is
required. Single wafers are normally not replaced on the
switches used in the Type 585. If one wafer is defective
the entire switch should be replaced. Switches can be
ordered from Tektronix either wired or unwired as desired.
Tube Replacements
Care should be taken both in preventive and corrective
maintenance that tubes are not replaced unless they are
actually defective. Many times during routine maintenance
it will be necessary for you to remove tubes from their
sockets. It is important that these tubes be returned to the
same sockets unless they are actually defective. Unneces 
sary replacement or switching of tubes will many times
necessitate recalibration of the instrument. If tubes do re 
quire replacement, it is recommended that they be replaced
by previously checked high quality tubes. The best way
to check tubes is by placing them in the circuit and check 
ing for proper operation.
REPLACEMENT PARTS
Standard Parts
Replacements for all parts used in the Type 585 Oscillo 
scope can be purchased directly through your area Tektronix
Field Engineer or Field Office. However, since many of the
components are standard electronic parts, they can generally
be obtained locally in less time than is required to obtain
them from the factory. Before ordering or purchasing parts,
be sure to consult the parts list to determine the tolerances
and ratings required. The parts list gives the values, tol 
erances, ratings, and Tektronix part numbers for all com 
ponents used in the instrument.
Special Parts
In addition to the standard electronic components men 
tioned in the previous paragraph, special parts are also
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