GW Instek GFC-8010H - Manual (Page 7)

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5-3. Maximum input voltage
The maximum input voltage Vs frequency characteristics is shown as
Fig. 6.
Fig. 6. Maximum Input Voltage-Frequency
5-4. Typical Applications
Several examples for typical applications are described below:
1).The output frequency of a transmitter or transceiver can be measured
(if the output power is about 1W) by merely connecting a one turn clip
cord to several tens of centimeters from antenna. The length of the
distance is determined by the magnitude of the output.
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2).Measurement can also be easily performed when calibrating the
oscillation frequency of a grid dip meter by merely connecting the one
turn clip cord.
3).Measurement of tracking the frequency through the oscillator stage,
multiplier stage, and output stage can be performed by making a small
2-3 turn coil and coupling it to each turned circuit (the oscillations may
be produced by the input capacitance and its resonant frequency with
too many turns of coil.)
Note: As the product has a high sensitivity, induction may cause
erroneous counting if you touch the red end (ungrounded side) of
the clip cord. Therefore, hold the black clip or coaxial cable when
performing measurements according to above method.
Measurement by connecting the accessory cable directly to the test
circuit is described below.
4).Measurement can generally be performed by merely connecting the
black side of the clip cord to ground (GND) and the red side to the test
point.
5).When the capacitance of the cable will have an affection on the test
circuit (When measuring turned circuits or high output impedance
circuit), perform measurement by inserting a high resistance in series
with the red side of the clip cord. Always be sure to ground the cord
when perform the measurement of 4) and 5) above. If possible, ground
the cable to the ground point of the test circuit. This procedure will
reduce the affection of noise. A wide variety of measurement can be
conceived in addition to (1~5) fully utilizing the special features of the
counter.