Subject to change without notice
19
F u n c t i o n s
Functions
Function selection
The type of output signal is selected with the func-
tion selection switch . A total number of 4 diffe-
rent waveforms (sine, square, triangle and pulse)
are available. The functions are marked with the
corresponding symbols. If the ON-pushbutton
is activated a DC voltage level is supplied by the
HM8030-6 (all function LEDs off) or superim-
posed on the output signal, except in pulse mode.
The max. offset voltage is ±5 V with open outputs
and is continuously adjustable with the OFFSET
control .
In pulse mode no offset voltage is available. With
control pulse width is continuously adjustable
from 10% to 90%. In postition OFF of pushbutton
a fixed pulse width of 50% is delivered.
Frequency adjustment
Coarse adjustment is performed with the range
keys . The desired frequency is selected by
turning the FREQUENCy control . The selected
frequency appears on the 5-digit display .
Output amplitude and signal connection
Adaptation in decade steps to the desired am-
plitude range is performed by the use of two
attenuators with –20 dB each, which are activated
by pushbuttons .
Including the continuously adjustable AMPLI-
TUDE control , the maximum attenuation
amounts to –60dB. With the maximum amplitude
of 10V
pp
, the minimum signal voltage to be sup-
plied is about 10mV. These values are obtained
when the generator output is terminated into
50 Ω. In the open-circuit condition, the available
signal amplitude is twice as high. Therefore the
maximum output voltage of the output socket
is specified with 20V
pp
. If exact square-shaped
signals are required, care should be taken that
only 50 Ω coaxial cables (e.g. HZ34) are used.
Furthermore, this cable must be terminated into a
50 Ω through-termination (e.g. HZ22). If these pre
-
cautions are not observed, overshoot may occur,
especially when high frequencies are selected.
If test circuits having a 50 Ω input impedance are
connected, this termination is not required. In high
signal voltage ranges, it should be noted that the
terminating resistor used must be specified for
the power dissipated.
The output terminal of the HM8030-6 is short
circuit proof. However, if an external DC-voltage
exceeding ±45 V is applied to the output, the
output stage is likely to be destructed. It can
withstand DC-voltage up to ±45 V for a time of
max. 30 seconds.
If the output of the HM8030-6 unit comes into
contact with components of the circuit under
test, which are carrying DC voltage, an isola-
tion capacitor of appropriate dielectric strength
should be connected in series with the output of
the generator. The capacitance of this isolating
capacitor should be selected in that way that the
frequency response of the output signal is not
affected over the whole frequency range of the
HM 8030-6 unit.
Trigger output
In the sine, square and triangle modes, the trigger
output supplies a square signal in synchronism
with the output signal. An offset voltage adjusted at
the 50 Ω output has no influence upon the trigger
signal. The trigger output is short-circuit-proof
and can drive several TTL inputs. If the trigger
output is terminated into 50 Ω, the trigger level
will fall below TTL specifications. Therefore short
or low-capacity cables without a 50 Ω termination
are to be used.
Sweep facilities
1
st
Internal sweep
The internal sweep facility of the HM8030-6
allows checking of filters and equipment in the
frequency range from 3Hz to 10 MHz. Operation
is very easy and does not require more than
setting of the start and stop frequencies and
the sweep time. Activation is by simply pressing
the SWEEP-pushbutton (START-LED lights) .
Sweep can be combined with all available func-
tions on the HM8030-6. The start frequency is
automatically given by the settings of the range
selector
and the frequency dial and is
shown on the 5-digit display. It can be set to any
