Boonton 4500B Peak Power Meter - Manual (Page 338)

Boonton 4500B RF Peak Power Analyzer
Maintenance 7-6
9. Remove the 15 dB attenuator and connect the HP8481A sensor directly to the Model 4500B
1 GHz calibrator output.
10. Zero the EPM power meter.
11. Set the calibrator output level to 0.0 dBm.
12. Enable the calibrator output by selecting Calibrator > Cal Output > ON.
13. Set a reference on the EPM power meter at 0.0 dBm.
14. Enter the calibrator level listed in Table 7-3b and record the EPM power meter measurements
in the column labeled ―Measured.‖
Calibrator 0 dBm Verification
To verify the calibrator 0 dBm RF output power level accuracy:
1. With the 432A power meter off and AC power disconnected, measure the resistance between the
center pin of the Vrf connector on the rear panel of the 432A and pin 1 on the thermistor mount
end of the 432A interconnect cable with the multimeter. Record the multimeter indication in
ohms to two decimal places. The value of the measurement should be approximately 200 ohms.
Label this measurement R.
2. Connect the 432A to AC power and set the line switch to ON.
3. Ensure the 4500B calibrator output is off by selecting Calibrator > Cal Output > OFF. Limit the
maximum output power to 0 dBm by selecting Calibrator > Max Power > 0 dBm. Connect the
thermistor mount to the 4500B calibrator output. Wait thirty minutes before proceeding to the
next step. This will allow the thermistor mount to stabilize.
4. Set the 432A RANGE switch to COARSE ZERO and adjust the COARSE ZERO control to obtain
a zero indication on the 432A meter.
5. Set the 432A RANGE switch to –20 dBm and depress the FINE ZERO switch on the front panel.
6. Set the 432A RANGE switch to 0 dBm. Set the multimeter to measure VDC. Connect the
positive lead of the multimeter to the center pin of the V
comp
connector on the 432A rear panel.
Connect the negative lead of the multimeter to the center pin of the V
rf
connector on the 432A rear
panel.
7. Depress the FINE ZERO switch on the front panel. Record the multimeter indication in VDC to
six decimal places (nearest microvolt). Label this measurement V
0
.
Note
The multimeter should read in mVDC. To convert from mVDC to VDC, multiply the
multimeter indication by 1000.