Programmed" Frequency Setting; Wobble Generator (Sweep) - VOLTCRAFT 8202 Notice D'emploi

7.6 "Programmed" frequency setting

Certain frequencies can be „programmed" on the generator via pre-selected control voltages from 0 to
10V. The control voltage is applied at the input „VCF IN". The setting on the frequency generator is
restricted to a minimum.
Simply set the desired frequency range and the knob „FREQUENCY" to the position „MIN".
Apply a certain fixed direct voltage on the VCF input in order to achieve the desired frequency at the
generator output.
IF several frequencies are required within a frequency range, e.g. for test fields or in quality assurance,
you can apply different direct voltages via a multiple-contact switch on the VCF input.
Never exceed the max. input parameters, neither on the VCF input nor on the fre-
quency counter input, and do not cause a short circuit on the generator outputs
"TTL/CMOS-OUT" and "OUTPUT". Otherwise you may damage or destroy the fre-
quency generator.
Danger of a mortal electric shock when exceeding the max. input parameters or
coming into contact with voltages in excess of 25 VAC or 35 VDC.

7.7 Wobble generator (SWEEP)

The wobble generator enables linear frequency changes at the signal output. The frequency band and
the number of wobble sequences can be set.
In order to apply the frequency generator as a wobble generator, proceed as follows:
a) Set the function generator as described in 7.1.
b) Press the desired range switch in the field „FREQUENCY RANGE (Hz)" (13), which the wobble gene-
rator is to pass through.
c) Set the frequency knob (18) to the position „MIN" or to the position at which the wobble process is
supposed to start (e.g. 100 Hz in the 1k range).
d) Pull out the knob "WIDTH" (15); the wobble function is active now.
e) The wobble speed (refresh rate) can be set via the button „RATE" (16).
f) With the knob „WIDTH" (15), you can set the wobble bandwidth within the selected range.
g) The display (2) shows a continuous change of the frequency. However, with fast wobble cycles it may
happen that the display cannot show the actual frequency course. This is due to the fixed gate time of
the counter, which does not change when adjusting the refresh rate (RATE).
We recommend attaching an oscilloscope to monitor or check the settings.
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