Step 2. Operator's Check - Agilent Technologies 8753ET Service Manual

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Step 2. Operator's Check

Step 2. Operator's Check
Description
The operator's check consists of two tests to check Port 1 and Port 2 on the 8753ES, or the
Reflection and Transmission port on the 8753ET. These tests are initiated via the front
panel of the analyzer and are called "Port 1 Op Chk" and "Port 2 Op Chk."
The operator's check determines that:
• The source is phase-locked across the entire frequency range.
• All three samplers are functioning properly.
• The transfer switch is operational (8753ES only).
• The attenuator steps 10 dB at a time. (8753ES and 8753ET Option 004 only)
Port 1 (8753ES) or Reflection Port (8753ET)
A short is connected to Port 1 to reflect all the source energy back into the analyzer for an
A/R measurement.
For the 8753ES, the first part of "Port 1 Op Chk" checks the repeatability of the transfer
switch. An S measurement is stored in memory and the switch is toggled to Port 2 and
11
then back to Port 1 where another S measurement is made. The difference between the
11
memory trace and the second trace is switch repeatability. This procedure is absent from
the routine for the 8753ET, since it lacks a transfer switch.
The remaining part of the test exercises the internal attenuator in 10 dB steps over a
70 dB range.
The resulting measurements must fall within a limit testing window to pass the test. The
window size is based on both source and receiver specifications.
Port 2 (8753ES) or Transmission Port (8753ET)
"Port 2 Op Chk" is essentially the same as "Port 1 Op Chk" for the 8753ES. The short is
placed on Port 2 for the procedure.
For the 8753ET, the procedure calls for connecting a through cable between the Reflection
and Transmission ports. RF power is obtained from the Reflection port. Again, the test
exercises the internal attenuator (if the analyzer has Option 004) and checks that the B/R
measurement falls within acceptable limits.
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