Tektronix WFM 601i, Руководство пользователя

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Installation
1–16
WFM 601i Serial Component Monitor
A terminator can be inspected for return loss problems using the WFM 601i and
a serial source with low aberrations, such as the TEKTRONIX TSG 422,
Option 1S Digital Component Generator. Connect the generator serial output to
one side of the WFM 601i loop-through and place the terminator on the other
side. Select the EYE mode and observe the eye pattern, paying particular
attention to leading edge aberrations.
Figure 1-10 shows the eye pattern with a good return loss terminator and Figure
1-11 shows the eye pattern of a terminator having only 13 dB return loss at
100 MHz (capacitive). Terminations causing aberrations of under 10% should be
acceptable.
Figure 1-10: Eye pattern display of a termination with good return loss.
Figure 1-11: Eye pattern display of a termination with poor return loss.
One final note: Most video equipment bnc connectors, whether 50 or 75
W
, use a
50
W
standard center pin. Some laboratory 75
W
bnc connectors use a smaller
diameter center pin. The bnc connectors on the WFM 601i are designed to work
with the 50
W
standard (large diameter) center pins.
Do not use connectors or terminators with the smaller center pins. They could
cause an intermittent connection.