HP 120A - Page 22

Sect. II Page 6
INTERNAL SWEEP - EXTERNAL SYNCHRONIZATION
5. Set SYNCHRONIZATION switch to EXTERNAL.
1. Feed vertical input signal to vertical input
terminals. Remove jumper for balanced in 
put (10 mv only).
2. Set AC-DC switch to type of input coupling
desired (balanced ac, see Figure 2-5).
3. Adjust VERTICAL SENSITIVITY control for
desired deflection.
6. Adjust SWEEP TIME HORIZONTAL SENSI 
TIVITY control for desired sweep speed.
7. Set TRIGGER LEVEL control to AUTO 
MATIC sweep or rotate TRIGGER LEVEL
control to desired trigger-level point.
4. Feed external synchronization signal to hori 
zontal input terminals (ac coupling only with
external synchronization).
This procedure is useful when it is desired to
observe phenomena occurring at random intervals.
Figure 2-4