In Normal mode, the repetition rate genera-
tor is free-running at the frequency set on the rate con·
trois. The pulse output is the same as on the oscilloscope
(the trigger output is identical to the pulse output). The
pulse duty cycle is 40-60%.
Set BOB1 A mode switch 3 to EXT. GATE
and press the MAN pushbutton. The repetition rate
should start when the button is pressed and stop when
the button is released. When the button is pressed, i. e.
when the gate opens, the first pulse should always start
at the beginning. However, when the button is released,
i. e. the gate closes, the last pulse may be cut short.
A suggested equipment setup for the Operat-
ing Instructions is shown in figure 3-3.
The B081 A Rate Generator must be mounted in an
BOBOA Mainframe. The following procedure is designed
to give a full understanding of the function of each of
the 8081 A operating modes.
Set the LINE switch on the 8080A Main-
frame to ON.
In TRIGGER mode, the repetition rate of
the output is independent of the internal repetition rate
generator. The output is, in fact, a pulse-shaped version
of the input signal. The input can be either external via
the EXT INPUT
or local using the MAN pushbut-
For external triggering, an external signal source
is required. The test set is as shown in figure 3-3. The
changes in control settings are as follows.
Initial Control Settings
RATE range switch
1 MHz-100 KHz
EXT INPUT LEVEL
Channel A internal
Pulse Generator: switched off.
Switch pulse generator on.
Set pu Ise period to about 15 fJ.sec.
Set pulse width to about 8 fJ.sec.
Set pulse amplitude to 2V and polarity to
Set the oscilloscope to trigger from chan-
nel B internally.
The 8081 A has four different operating
External Gate (EXT GATE)
Internal Gate (INT GATE)
The oscilloscope display should be as shown
in figure 3-4. The 8081 A output should only be
delayed on the external input by the internal circuitry
delay of the 8081 A
Figure 3-4. Rate Generator Output in Trigger Mode.