WFM700 Series Waveform Monitors Service Manual 3-17
This procedure adjusts the scale factor for the HD jitter display and the measured
jitter readout. This adjustment is only available for the WFM700M (WFM700
with a WFM7M video module).
Following is a list of the signal requirements to perform the adjustment.
Adjacent to the requirement is the recommended equipment and test signals.
Adjustment requirements Recommended test equipment and test signal
Calibrated sine wave generator,
741.7582 MHz, 800 mV into
75 8, FM modulated to generate
2 UI jitter amplitude
With the recommended RF generator, you can modulate the
signal with the following settings to obtain 2 UI of jitter.
Frequency 741.7582 MHz
Output Level 0 dB
Frequency Modulation OFF
LFGEN2 Frequency 10 kHz
LFGEN2 Waveshape SQUARE
Phase Modulation Source LFGEN2
Phase Deviation 3.14 RADIANS
RF Output ON
Phase Modulation ON
75 8coaxial cable 36 inches long
NOTE. If this test is performed out of sequence or the sequence of tests has been
interrupted (such as power off or input from another module was selected),
perform the steps in this note to prepare the instrument to continue testing.
a. Connect the SD video generator to INPUT B usinga758cable.
b. Set the SD video generator for a 525-format 100% color bar signal.
c. Press the INPUT button and select Input B.
d. Press the EYE button.
e. Press the INPUT button and select Input A.
1. Install the 50 8N-to-BNC adapter on the RF generator output.
2. Connect the RF generator output to INPUT A using a 75 8cable. Imped-
ance matching is not important for this connection.
3. Touch the HD Jitter Gain Adjust soft key and then the Start HD Jitter
Gain Adjust soft key.
4. Adjust the signal amplitude using the General Purpose Knob to 2 UI as
measured on the display. See Figure 3--12.
5. Touch the Save and Exit soft key to save the new calibration constant.
HD Jitter Gain Adjust