Frequency Counter - VOLTCRAFT FG 8210 Bedienungsanleitung

8.8 EXTERNALLY CONTROLLER WOBBULATOR
The wobbulator can also be set via the VCF control input.
To use the function generator as voltage-controlled sweep generator, proceed as follows:
• Use the function generator as described in chapter 8.7. The adjustment button "WIDTH" remains pushed, however
(do not pull). No setting is required at the adjustment button "RATE" or "WIDTH" either.
• Apply a direct-voltage free, asymmetrical change signal to the VCF-input (5). An amplitude of 0 to 10 V permits a
wobble ratio up to 100:1. The curve shape is unimportant. Observe that the dropping flank of the signal is larger
than the rising flank (changed symmetry).
We recommend connecting an oscilloscope (if present) to monitor or review the settings.
Never exceed the max. input values, neither at the VCF-input nor at the frequency counter input,
and avoid a short circuit at the generator outputs "TTL-SYNC" and "OUTPUT". Otherwise, there is
the danger of damage or even destruction of the frequency generator.
When the max. input values are exceeded or voltages above 50 V/AC or 75 V/DC are touched,
there is the danger of a potentially fatal electric shock.

8.9 FREQUENCY COUNTER

The frequency generator can be used as frequency counter.
For this, switch the display to external counter operation via the switch "COUNTER INT/EXT" (17).
Switch pushed:
Switch not pushed:
Select the frequency range "FREQUENCY RANGE 1" (13).
The counter input (4) is designated "EXT COUNT IN" and can be used for frequencies up to 100 MHz.
A "low-pass filter" is installed to be able to measure even lower frequencies (<100 kHz) without interferences. This
suppresses high frequency shares (-3dB) that may falsify the measurement.
Push the switch "LPF" (17) during frequency measurement below 100 kHz. This switch must not be pushed at high
frequencies.
The measuring signal must be galvanically separated from the mains. The amplitude must not
exceed 48 Vpp (tip-tip). The input is protected against overload up to a signal voltage of 250 Vpp.
After application of a frequency of at least 2 Hz to max. 100 MHz with a signal voltage galvanically separated from
the mains and a max. amplitude of 48 Vpp (= tip-tip), it is displayed on the 7-digit display. Other buttons for operation
of the frequency counter are not required. The decimal point, the measuring units and the gate time are automati-
cally set to the expected measuring signal. The input sensitivity is at least 100 mVrms.
The last measured frequency is retained in the display until a new measurable signal is recognised. When discon-
necting the measuring line, the last measured value is retained until the function is changed or a new signal applied.
Never exceed the max. input values, neither at the VCF-input nor at the frequency counter input,
and avoid a short circuit at the generator outputs "TTL-SYNC" and "OUTPUT". Otherwise, there is
the danger of damage or even destruction of the frequency generator.
When the max. input values are exceeded or voltages above 50 V/AC or 75 V/DC are touched,
there is the danger of a potentially fatal electric shock.
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External counter operation
Internal generator display