HP 8648 A/B/C/D - Changpuak.ch

LF Power Level
Accuracy
All HP 8648BKYD
HP 8648BK
Frequency Range
Description
Required Test
Equipment
Procedure
LF Power Level Accuracy
Early versions of the HP 8648B and HP 8648C have a frequency range
that begins at 100 kHz rather than 9 kHz. If the DUT has a frequency
range that begins at 100 kHz, do not run this adjustment.
This adjustment covers the frequency range of 9 to 100 kHz and the
dynamic range of 0 to -100 dBm. Initially, the spectrum analyzer is
checked to verify that its noise floor and any residuals are at least
20 dB below the lowest signal measured. If a residual is detected, the
frequency is shifted plus or minus 25 Hz. If the noise floor is too high,
the adjustment is exited.
Signal levels between 0 and -40 dBm are measured directly with a
digital voltmeter (DVM). Lower signal levels are measured using the
spectrum analyzer. All spectrum analyzer measurements are relative
to the -40 dBm DVM measurement.
w DVM
Spectrum Analyzer
w 6 dB Attenuator
w 50 62 Feedthrough
HP 8648
UNDER TEST
DIGITAL MULTIMETER
Figure 7-3 1.
LF Power Level Accuracy Test Setup
for Power Levels of 2 -40 dBm
Feed Through
Adjustments 7-3 1