420 Chapter 2
Performance Verification Tests
59. Comms Absolute Power Accuracy (Options BAC or BAH)
NOTE The external attenuators and cables are now part of the “source.”
5. Set the analyzer as follows:
FREQUENCY, Center Freq, 50 MHz
SPAN, 0 kHz
BW/Avg, Res BW, 10 kHz
BW/Avg, Video BW, 10 kHz
AMPLITUDE, More, Y-Axis Units (or Amptd Units), dBm
AMPLITUDE, Ref Level, –20 dBm
AMPLITUDE, Attenuation, 0 dB
AMPLITUDE, More, Int Preamp Off
6. Perform the following steps for each of the “Nominal Input
Amplitude” values listed in Table 2-127.
a. Set the 1 dB step attenuator as indicated.
b. Set the 10 dB step attenuator as indicated.
c. Set the analyzer reference level as indicated.
d. Set the analyzer input attenuation as indicated.
e. Press Single and wait for the sweep to finish.
f. Press Peak Search (or Search). The marker can still make a valid
measurement, even though the signal may be slightly above the
reference level for the first nominal amplitude setting.
g. Record the marker (Mkr1) amplitude value as the Measured
Amplitude in Table 2-128.
Table 2-128 Amplitude Accuracy Worksheet
1 dB Step
Attenuator
10 dB Step
Attenuator
Total
Attenuation Ref.
Level
Nominal
Input
Amptd
Meas
Amptd
Amptd
Accuracy
Setting Actual Setting Actual Setting Actual
0 dB 40 dB 40 dB –20 dBm –40 dBm
0 dB 40 dB 40 dB –40 dBm –40 dBm
0 dB 60 dB 60 dB –40 dBm –60 dBm
0 dB 60 dB 60 dB –60 dBm –60 dBm
0 dB 70 dB 70 dB –50 dBm –70 dBm
0 dB 70 dB 70 dB –70 dBm –70 dBm
0 dB 80 dB 80 dB –60 dBm –80 dBm
0 dB 80 dB 80 dB –80 dBm –80 dBm
0 dB 80 dB 80 dB –65 dBm –85 dBm
5 dB 80 dB 85 dB –85 dBm –85 dBm