Gain Factors In The Src Rf Paths - Keysight Technologies N52 Series User's And Service Manual

Service Information
Gain Factors for the SRC RF Paths
Background
The controller board in the test set stores gain factors for the various SRC RF
paths in non-volatile memory. These gain factors are used by the PNA firmware
to ensure that the SRC RF power delivered to the mm-wave head is
approximately 11 dBm when the ALC is off.
When a component in a SRC RF path is replaced it is necessary to measure the
new gain factors and update the values stored on the controller board. Typically
the gain factors must be updated whenever one or more of the components in an
"RF Section" of Figure 2-3, "N5261A RF and LO Block Diagram"
"N5262A RF and LO Block Diagram"
When a controller board is going to be replaced, if possible, the gain factors
should be read from the old controller board before it is removed from the test
set. After the new controller board is installed the gain factors must be written
into the test set. If the gain factors cannot be read from the old board then the
gain factors must be measured after the new controller board is installed.
Instructions for issuing Test Set I/O commands are contained in the
"Preparation"
indicates which procedure(s) is required.
Measure Gain Factors for Ports 1 and 2 (Procedure A)
1. Connect the SRC 1 jumper on the rear panel of the test set.
2. [Preset] the PNA. Set the measured frequency range from 7 GHz to 20
3. Set the PNA power output level to −15 dBm. Set the PNA to measure S12.
4. Connect cables to PNA Ports 1 and 2. These two cables will allow
5. Connect the two cables together using an adapter and perform a
6. Connect PNA Port 2 to SCR1 IN and PNA Port 1 to Test Set Port 1 RF OUT.
7. Set markers for 7, 10, 15 and 20 GHz on the PNA trace.
8. Read the value for each marker and translate to tenths of a dB (round the
9. Record the values for Port 1 in
10. Issue the Test Set I/O command 0,2 to set the path to Port 2.
Keysight N5261/62A User's & Service Guide
section beginning on
GHz.
connection to the front panel of the test set.
normalization calibration. Refer to
Information" on page 50
Issue the Test Set I/O commands 32,1 and 0,1 (turn off SRC1 ALC and set
path to Port 1).
raw number as required). Example: a reading of 25.34 dB would be
translated to a value of 253.
is replaced.
page 68. Table 2-4 on page 78
"Part Replacement and Location
for instructions.
Table 2-5 on page
or Figure 2-4,
81.
79