U3042AE16
Troubleshooting the Test Set
RF Switching Failures
If the test set’s RF signal functionality is not operating properly, use the following procedure to
aid in isolating the source of problem. The internal RF solid state switches used in this
instrument are biased with the +15 Vdc supply voltage and controlled logic signals coming from
the test set Controller board and Switch Interface board.
1.
Place the network analyzer and test set side by side (not stacked) and connect the I/O cable
.
2.
Ensure that the network analyzer is
not
in Multiport Mode.
3.
Using the test set I/O Data command values, confirm the correct address and data values
“Address and Data Values” on page 4
a.
Each RF solid state switch has a Bias/Logic control board. This board has four port status
LEDs. When a switch control signal is created, the switch port status LED will indicate
which switch port is being selected. Refer to
“RF Switching Path Test” on page
.
b.
If the LEDs
on
the Switch are
off
when that switch is selected, verify that the ribbon cable
is installed on the correct connector on the Switch Interface board. If the connection is
correct, substitute a working switch or ribbon cable. Swapping can be performed in this
situation.
RF Switching Path Test
If you suspect an RF signal path problem with the test set and have verified that the problem in
not the front panel RF interface cables, the following procedure will check all of the RF signal
paths through the test set.
• Install the test set I/O cable from the analyzer to the test set rear panel.
• Remove the front panel RF interface cables and reinstall the analyzer’s front panel jumper
cables.
Equipment Required
• PNA, PNA-L or PNA-X Network Analyzer
• Two RF Flex Cables (3.5 mm male)
•
3.5 mm Adapters (female to female)
• Test Set I/O Cable
70
User's and Service Guide U3042-90012
