Maintenance— Type 1L20
Removing and Remounting the IF Chassis
1. Loosen the front set-screw on the DISPERSION RANGE
switch shaft with a .05 inch Allen wrench and slide the shaft
out through the front panel.
2. Remove the two screws securing the DISPERSION
RANGE switch to the rear plate and swing the switch
assembly out of the way behind the rear plate.
3. Remove the fourteen Phillips head screws fastening
the IF chassis to its base.
4. Swing the chassis up and out to rest on the instru
ment's spacer bars (See Fig. 4-2). (It may be necessary to
disconnect the coaxial cable from J147.) Do not use force,
because some o f the parts are critically positioned and
should not be moved out of adjustment.
5. Before turning on the power, check to make sure that
none o f the terminals and tie points are shorted or grounded.
Also, reconnect any cables or wires that were disconnected.
The ground-wire on the DISPERSION RANGE switch must
be grounded for proper operation o f the instrument.
6.
Remount the IF chassis using the reverse of the pro
cedures of steps 1 through 5. Do not force the chassis into
place and check the wiring and connectors to prevent
pinching and straining of the connections. When replacing
the DISPERSION RANGE switch, be sure its shaft is properly
coupled to SW365. Also check the operation of the DIS
PERSION RANGE switch to be sure the knob is properly
indexed.
Removing the Phase-Lock Assembly
1. Turn off the power.
2. Unplug all the leads connected to the phase-lock
assembly.
3. Use a Vi* inch Allen wrench to remove the FINE FREQ
control knob.
4. Use a 5/ 1<s inch nutdriver to remove the nut securing the
rear end of the phase lock assembly to the main chassis,
and the nuts securing the front-panel phase-lock controls.
IMPORTANT
Keep the nut securing the INT 1 M Hz REF FREQ
switch separate from the others. It has a slightly
different thread and w ill bind if it is placed on
the wrong control.
5. Remove V260 (next to the square pin connectors).
6. Slide the phase-lock assembly back and toward V620
socket until the control shafts are clear o f the front panel.
7. Remove the six Phillips head screws located along the
edge of the ‘‘U” -shaped phase-lock cover and slide out the
assembly.
Be careful that the low-pass filter mounting
screws on the cover do not catch on the chassis.
8. If you expect to turn on the power with the assembly
removed, replace V620, the three control nuts you removed
4 -3
Fig. 4 -2 . Removing Hie IF Chassis.
Содержание 1L20
Страница 4: ...Type 1L20 Fig 1 1 Type 1L20 Spectrum Analyzer...
Страница 16: ...NOTES...
Страница 18: ...Fig 3 1 Block Diagram of the Type 1L20 N Circuit Description Type 1L20...
Страница 32: ...Maintenance Type 1L20 4 10 Fig 4 6 Phase Lock and Recorder Detector Circuit Boards...
Страница 42: ...Calibration Type 1L20 4B 40 4D 4E 6 2 Fig 6 1 Recommended equipment for calibrating the Type 1L20...
Страница 43: ...Calibration Type 1L20 10 11 12 13 14 15 6 3 Fig 6 2 Recommended Calibration tools and equipment...
Страница 94: ......
Страница 97: ...N0I133S 3H ZHU i...
Страница 98: ...TYPE IL LO SPECTRUM ANALYZER A P H A S E LO C K U S C IR C U IT 2 PHASE LOCK CIRCUIT...
Страница 100: ...T 1 SW EEPER CIRCUITS...
Страница 102: ...N B IFA M PL 70 MHz OSC 6...
Страница 103: ...I o o z o o 5 1166 TYPE IL Z 0 IL 3 0 SPEC TR U M ANALYZER A VARIABLE RESOLUTION CIRCUITS T V A R IA B L E RESOL...
Страница 104: ...5 M H z AM PLIFIE R D E TECTO RS TYPE IL Z O IL 3 0 S P E C T R U M ANALYZER A OUTPUT AMPLIFIER OUTPUT AMPLIFIER...
Страница 105: ...TYPE 1L20 SPECTRUM ANALYZER...
Страница 106: ...FIG 2 REAR CHASSIS TYPE 1L20 SPECTRUM ANALYZER 1 F IG 2...
Страница 107: ...FIG 3 IF CHASSIS T i T L A TYPE 1L20 SPECTRUM ANALYZER F I G 3...
Страница 108: ...FIG 4 LOW PASS FILTER PHASE LOCK ASSEMBLY FIG 4...
Страница 110: ...OPTIONAL ACCESSORIES TYPE 1L20 SPECTRUM ANALYZER...
Страница 112: ...TYPE 1L20 TYPE 1L30 PARTS LIST CORRECTION CHANGE TO R823 30 0181 00 180 a 1W 10 Cl 366...