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3-3. Frequency Measurements
3-3-1
INPUT A, B (0.1 Hz to 100 MHz)
a. Apply the signal to be measured to the input A and/or B(FC-7150U, FC-
7015U only) BNC.
b. Set the FREQ. A and/or B(FC-7150U, FC-7015U only) of function switch.
c. Select the degree of resolution desired, using the gate time
selector switch.
d. Frequency is given by the display. The gate indicator lights while each
measurement in progress, and the display is updated at the end of each
measurement interval.
e. Engaging the hold switch “freezes” the display at the existing reading,
When hold is released, the display is updated and resumes counting.
f. If necessary, engage the attenuator switch When set to x 10 (pushed
in), this switch attenuates the input A and/or B(FC-7150U, FC-7015U only)
signal by a factor of approximately 10 before application to the counter.
This helps prevent miscounting caused by noisy or improperly terminated
high amplitude signals.
g. If necessary, engage the LPF (low pass filter) switch This route the input
A and/or B through a low pass filter (-3 dB point of approximately 100
KHz) before application to the frequency counter. This helps eliminate
counting errors in low frequency measurements by minimizing effects of
high frequency noise present on the input.
h. When measurement the lower cut-off frequency (10 Hz), pushed in DC
coupling position.
3-3-2
INPUT C
FC-7150U, FC-7150: 80 MHz to 1.5 GHz
FC-3000 : 80MHz to 3.3GHz
CAUTION
THE MAXIMUM INPUT LIMIT TO THIS INPUT IS 3 Vrms MAXIMUM OVER THE
INPUT FREQUENCY RANGE. THE X 10 ATTENUATOR DOES NOT APPLY.
a. Apply the signal to be measured to the input C. BNC.
b. Set the function indicator to the FREQ. C position.
c. Select the degree of resolution desired, using the gate time switch.
d. Frequency is given by the display. The indicator lights while each
measurement in progress.
e. Engaging the hold switch “freezes” the display at the existing reading,
When hold is released, the display is updated and resumes counting.
f. The attenuator and LPF coupling switch have no effect in input C.
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