3Adjustments
80 Keysight E4416A/E4417A Power Meters Service Guide
Procedure
1 Set up the DVM to measure resistance. Connect the DVM between the VRF
connector on the rear panel of the Keysight 432A and pin 1 on the thermistor
mount end of the sensor cable. Verify that no power is applied to the Keysight
478A.
2 Round off the DVM reading to two decimal places and record this value as the
internal bridge resistance (R) of the test power meter (approximately 200 Ω).
– R (Internal Bridge Resistance)_______________ Ω
3 Connect the equipment as shown in Figure 3-3. The leads should be isolated
from ground. Ensure that the power reference oscillator is off. Ensure that both
the power meter under test and the Keysight 432A have been powered on for
at least 30 minutes before proceeding to the next step.
4 Set the Keysight 432A range switch to coarse zero and adjust the front panel
coarse zero control to obtain a zero meter indication.
5 Fine zero the Keysight 432A on the most sensitive range, then set the range
switch to 1 mW.
6 Set up the DVM to measure microvolts.
7 Connect the positive and negative input leads, respectively, to the V
comp
and
V
RF
connectors on the rear panel of the Keysight 432A.
8 Observe the reading on the DVM. If less than 400 μV, proceed with the next
step. If 400 μV or greater, press and hold the Keysight 432A fine zero switch
and adjust the coarse zero control so that the DVM indicates 200 μV or less.
Then release the fine zero switch and proceed to the next step.
The procedure details the key presses required on the Keysight E4416A. For the
Keysight E4417A the equivalent key presses should be performed on both
channels.
Ensure that the DVM input leads are isolated from chassis ground when
performing the next step.