Keysight Technologies N5261A, User'S And Service Manual

Page: 74 / 99

Service Information
2-
If you suspect the LO Amp (5086-7771) , substitute the RF Amp
(5086-7771) to verify the failure. The LO Amp uses a leveling circuit with
directional coupler and detector that also can be checked before replacing
the LO Amp. You may also substitute the Directional Coupler and Detector
from the RF Amp section.
REF IF or Test IF Failure
If the REF IF or Test IF fails the Operation Verification test the following
procedure can be used to verify the failure. The procedures assume power
supplies, controller board and front panel LEDs are working. Suspect the
switch Interface board or coaxial cables. Refer to Table 2-1 on page 6 6 and
Figure 2-1 3 on page 6 6 .
1. N5261A - Verify that the front panel Port 1 & 2 REF and IF coax cables are
properly connected to the rear panel (A, B, C and D) and insertion loss is
not > − 2.5 dB. Replace the coax cable if defective. Refer to Figure 2-1 on
page
51
.
2. N5262A - Verify that the front panel Port 1 & 4 REF and IF coax cables and
rear panel coax cables (A, B, C, D and R) are properly connected to the
Interface board. Verify that the insertion loss is not >
−
2.5 dB. Replace the
coax cable if defective.
3. If the coax cables are properly connected and the insertion loss is correct,
replace the Interface board. Refer to Figure 2-2 on page 5
2
.
Test Set Operation Check
This chapter contains service information for a standalone N5261A
and N5262A controller test sets.
The following procedure verifies the test set without mm-module
system components.
The instructions below generally assume a 4-Port N5262A. If you are
using an N5261A, omit Ports 3 and 4.
Preparation
Required Equipment
— PNA, PNA-L, PNA-X capable of 20 GHz. (The required Test Set I/O interface
is included with all models). The PNA, PNA-L or PNA-X will be referred to as
the PNA throughout this procedure.
— Two RF flexible cables with 3.5 mm male connectors (5062-6696 or
equivalent). One cable must be long enough to comfortably connect
between the PNA and the rear panel of the test set.
— Three SMA or 3.5 mm adapters (female to female)
6 8
Keysight N5261/62A User’s & Service Guide