Instruction manual

14
INT/EXT TIME BASE SELECTOR:
Selects the source of the time base. EXT.STD. IN sets
up BNC
as a nominal 600Ω input impedance path for
an external 10 MHz time base signal. INT. STD. OUT
sets up BNC
to monitor the internal time base signal.
GROUND TERMINAL
FUSE HOLDER: Replace fuse by unscrewing
INT/EXT TIME BASE BNC:
Provides a connector through which the internal time
base signal can be monitored or through which an
external time base signal can be applied (see item
above). The external signal should have a voltage
range of 1.5 V~5 V rms.
RS-232C CONNECTOR: Connector for serial interfacing with a computer.
3-2. Operating Instructions
a. Connect the unit up to the AC power.
b. Turn on the unit by pushing in the POWER on-off switch.
c. Set the FUNCTION indicator position to FREQ A and the gate TIME
indicator to the 1 Sec, position.
CAUTION
1. APPLICATION OF INPUT VOLTAGES HIGHER THAN THE LIMITS LISTED IN
THE SPECIFICATIONS SECTION MAY DAMAGE THE COUNTER. BEFORE
APPLYING ANY SIGNAL TO THE INPUTS, MAKE CERTAIN THAT IT DOES NOT
EXCEED THESE SPECIFIED MAXIMUMS.
2. FREQUENCY COUNTER GROUND POINTS ARE CONNECTED DIRECTLY TO
EARTH GROUND. CONNECT GROUND OF THE CIRCUIT UNDER TEST TO
THE FREQUENCY COUNTER GROUND ONLY