Model 122A Sect. IV Page 5
TABLE 4-2. SWEEP TIME ACCURACY
SWEEP TIME/CM Timing Signal Cycles Produced in
Position Frequency Period 9.5 to 10.5 cm
*200 MILLISECONDS 1 cycle 1 second 2
100 MILLISECONDS 10 cycles 100 milliseconds 10
50 MILLISECONDS 10 cycles 100 milliseconds 5
20 MILLISECONDS 10 cycles 100 milliseconds 2
10 MILLISECONDS 100 cycles 10 milliseconds 10
5 MILLISECONDS 100 cycles 10 milliseconds 5
2 MILLISECONDS 100 cycles 10 milliseconds 2
1. MILLISECONDS 1,OOO cycles 1 millisecond 10
.5 MILLISECONDS 1,000 cycles 1 millisecond 5
200 MICROSECONDS 1,OOO cycles 1 millisecond 2
100 MICROSECONDS 10 kilocycles 100 microseconds 10
50 MICROSECONDS 10 kilocycles 100 microseconds 5
20 MICROSECONDS 10 kilocycles 100 microseconds 2
10 MICROSECONDS 100 kilocycles 10 microseconds 10
5 MICROSECONDS 100 kilocycles 10 microseconds 5
* Use DC input coupling to avoid degrading input signal.
3) Set SWEEP EXPAND switch to X5. Two com- adequate safety precautions, especially when work-
plete cycles should now appear in 10 (fig) centi- ing around the cathode-ray tube terminals and the
neters of horizontal deflection. power supplies.
4-3 REMOVING THE CABINET 4-4 TUBE REPLACEMENT
Disconnect power cord and remove two large In many cases instrument malfunction can be cor-
screws on the rear of cabinet. Do not remove any rected by replacing a weak or defective tube. Be-
front panel screws. Slide oscilloscope forward fore changing the setting of any internal adjust-
3ut of cabinet. ment, check the tubes. Adjustments that are made
in an attempt to compensate for a defective tube
CAUTION will often complicate the repair problem.
[f the instrument is operated with the cabinet re- It is good practice to check tubes by substitution
moved, dangerous voltages are exposed. Take rather than by use of a ?tube checker?. The |