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he power levels tested for both high and low frequency units are based on known
characteristics of the receiver. Gain compression for the HP 8713C/14C is tested in the 0 dBm
0
to
20 dBm power range. Likewise, gain compression for the HP 8711C/12C/30A is tested in
0
the +10 to
10 dBm power range. Compression is tested in a narrow (250 Hz) bandwidth.
If This Test Fails
Repeat adjustments #101 and #105. If this does not solve the problem, replace the A5 receiver
assembly.
Noise Floor
he noise
oor test is divided into two sections; broadband and narrowband. During this test
the RF output is terminated in 50
or 75
and the RF input is shorted. For the broadband
portion, the analyzer is set to measure B* with averaging ON and with a narrow bandwidth.
Worst-case noise
oor is then measured starting from 10 MHz. For narrowband mode, the
noise
oor is measured with the B input (not B/R) in a ne bandwidth (15 Hz) and spur avoid
activated. his portion of the test is divided into two sections: frequencies below 5 MHz and
frequencies above 5 MHz.
If This Test Fails
First verify that all cable connections and screws are secure, then repeat adjustment #102. If
only the broadband portion fails, the A5 receiver diodes may be bad; see \ roubleshooting
the A5 Receiver Assembly" in the \ roubleshooting and Block Diagrams" chapter for more
information. Otherwise, the A5 receiver assembly is most likely bad, though spurs generated in
either the A3 fractional-N/reference or A4 source assemblies can also cause noise
oor failures.
Dynamic Accuracy
Dynamic accuracy is measured on the narrowband B detector at a CW frequency of 30 MHz,
from 0 dBm (if possible) down to
attenuator is used as the reference device. On 75
analyzers, two minimum loss pads must
be used to convert the impedance to 50
for the HP 8496A/G attenuator. he analyzer is set
to measure the B input in a ne (15 Hz) bandwidth. Power is rst measured at
all measurements are made relative to this point (generally this means the attenuator is set to
20 dB). he attenuator is then switched in 10 dB increments and the resulting power is read
from the analyzer. hese values are then compared to the known values of the calibrated step
attenuator. he di erence is the dynamic accuracy error of the analyzer.
Mismatch errors are minimal since the input/output match at 30 MHz is very good. For some
combinations of options on 75
analyzers, the 0 dBm point may not be obtainable. In this case,
only levels at and below
If This Test Fails
First repeat adjustment #102. If the problem persists, suspect calibration errors in the step
attenuator used to perform this adjustment; see \ he 40 dB step attenuator card selection (3)"
in \Performance est Software Installation" earlier in this chapter. Crosstalk can also a ect this
test; verify that all cables and screws are secure.
1-22
Performance T ests
0
100 dBm in 10 dB increments. A calibrated 10 dB step
0
10 dBm are tested.
0
20 dBm and
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