Tektronix 1L30, Instruction Manual

Page: 41 / 129

M ain ten an ce— Type 1L30
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2. loosen the two Allen screws in the rear mounting
bracket on the rear panel.
3. Release the rear panel by removing all screws except
the two holding the interconnecting plug, the two holding
the sawtooth voltage selector switch and the screws hold­
ing resistors R40, R49 and R727.
Position the rear panel
so as to gain access to the rear section of the oscillator
assembly.
4. Unsolder and disconnect the filament wires from the
plug-in connector to the blue standoff connector.
5. Disconnect the Sealectro connectors for the two coaxial
signal leads to the mixer assembly and the phase lock as­
sembly. Pull out on the connectors to disconnect.
6. Loosen the Allen set-screw, then remove the RF CENTER
FREQ tuning knob. Remove the retaining nut under the
knob that holds the dial mechanism to the front panel.
7. Lift out the RF section from the rear of the plug-in unit.
(Position the rear panel as necessary for adequate clear­
ance.)
8. Re-install the new oscillator assembly using the re­
verse of the removal procedure. Recalibrate in accordance
with the procedure outlined in the Calibration section.
Removal a n d /o r Replacement of the Oscillator
Tube
1. Perform steps 1 through 3 of the procedure for re^
moving the oscillator assembly.
2. Carefully, (by hand) unscrew and remove the large
knurled ring on the rear portion of the oscillator assembly.
See Fig. 4-4.
Fig. 4-4. Oscillator disassembled to show the sequence as the com­
ponents are removed or installed.
4 -4
3. Carefully remove the inner plate connector and lif}
out the large and small t’eflon insulating washers. This
exposes the tube and spanner retaining nut.
4. Using special tool Tektronix Part No. 003-0397-00 (see
Fig. 4-6) unscrew the spanner nut, then gently lift out the
tube while feeding the heater wires into the opening at the
front end of the oscillator.
5. Unsolder the filament leads from the tube and recon­
nect the leads to the new tube. Do not unsolder the wires
at the standoff insulators on the outside of the oscillator.
The replacement tube should be an assembly containing
the feedback block and wires. See Figs. 4-4 and 4-5.
Fig. 4-5. Oscillator p a rtia lly disassembled to show the position
of the tube when seated properly and the location of the calibration
adjustments.
6. Replace the insulation tape around the tube filament
connection and carefully insert the new tube assembly into
the oscillator making certain the tube is well seated in the
grid connector.
7. Replace the spanner nut with the special spanner
wrench and tighten by hand so the nut is snug. Tighten
only enough to make a good seat; do not over-tighfen.
8. Replace the two large teflon and the small teflon
washers with new washers. All three washers should be in­
spected to insure that they are free of dirt or foreign matter
that could puncture the washer.
9. Replace the internal plate connector and the large
knurled nut. As the large knurled nut is tightened, the op­
erator should move the large tuning choke in and out of
the tuning chamber by turning the tuning shaft, to insure
that it moves freely.
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