HP 85325A Operating and Service Manual 1-15
Installation
Adjustment Procedures
4. Connect the reference mixer to the reference module and directional
coupler, refer to Figure 1-5 on page 1-12. The warning beeper on the
receiver should stop.
5. Press
[ENTRY OFF]
to remove the error message from the receiver display.
Adjust the LO Power to
the Test Mixer
1. Measure the LO power output of the test module as shown in Figure 1-6
2. Look up the power level (see below) and perform the corresponding
action.
If power is:
❍
Less than 14.75 dBm: Reduce the amount of attenuation in the test
module until power is between 14.75 and 16.25 dBm.
NOTE
If you have removed all attenuators from the test module, and power is still
less than 14.75 dBm, this means that you cannot switch between the
HP 85325A mixers and your other mixers without readjusting LO power
each time. Perform “Procedure 1" on page 1-11 to adjust LO power for the
HP 85325A mixers. To adjust LO power for the other mixers, refer to the
operating manual for those mixers.
❍
14.75 to 16.25 dBm: Proper LO power, no further adjustment is
needed.
❍
Greater than 16.25 dBm: Add attenuation inside the test module
until power is between 15 and 16.25 dBm.
3. If you have more than one test module, repeat the power measurement
(the previous two steps) for each test module.