Agilent Technologies 8753ET User Manual page 149

The following steps can be performed to observe this offset in power:
1. To set the power range to manual, press:
Power
PWR RANGE MAN
Setting the power range to manual prevents the internal source attenuator from switching when
changing power levels. If you choose a different power range, the R channel offset compensation and R
channel measurement changes by the amount of the attenuator setting.
2. Connect the analyzer source output, port 1, directly to the R channel input as shown in
CAUTION To prevent connector damage, use an adapter (part number 1250-1462) as a connector saver
for R CHANNEL IN.
Figure 2-9 R Channel External Connection
3. To activate the frequency offset mode, press:
System
INSTRUMENT MODE
FREQ OFFS MENU
FREQ OFFS ON
Since the LO (offset) frequency is still set to the default value of 0 Hz, the analyzer will operate normally.
4. Measure the output power in the R channel by pressing:
Meas INPUT PORTS
Observe the 13 to 16 dB offset in measured power. The actual input power level to the R channel input
must be 0 dBm or less, 10 dBm typical, to avoid receiver saturation effects. The minimum signal level
must be greater than 35 dBm to provide sufficient signal for operation of the phaselock loop.
5. You cannot trust R channel power settings without knowing about the offset involved. Perform a receiver
calibration to remove any power offsets by pressing:
RECEIVER CAL
Cal
0 x1
R
0 x1
Making Mixer Measurements
Measurement Considerations
Figure 2-9.
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