HP 8340B Manual page 40

4-7. SPURIOUS SIGNALS TEST (10 MHz to 22 GHz
When using a spectrum analyzer other than the HP 8566A/B, the spec-
trum analyzer may generate some mixing products that could appear on
the display. If a signal is in question, increase the spectrum analyzer
input attenuation by 10 dB, note if signal decreases in amplitude by 10
dB, then return the attenuator to its original position. If the signal in
question comes from an external source, it will change by exactly 10 dB.
If the signal in question originates in the spectrum analyzer, the level will
either change by greater or less than 10 dB or may not change at all.
The DUT's rotary knob circuit may generate some noise spikes when the
knob is rotated. These signals should disappear when rotation is
stopped.
If a spurious signal is found and it appears out of specification, check
the fundamental signal amplitude to ensure it is at 0 dBm. Then check
spurious level by substituting a known amplitude signal on the spectrum
analyzer.
6. Tune the spectrum analyzer across its full frequency range. Look for any spurious signals. For
each spurious response determine what mechanism generated the spurious response and what
specification applies.
a. Is the spurious response in question an integer multiple of the HP 8340B/41B RF output
signal? If it is, the "harmonic" specification applies.
b. Press the DUT's [SHIFT] key and then [M2] to display, from left to right, the YO harmonic
number and the YO frequency. Is the spurious response in question an integer multiple of the
YO frequency (and not a harmonic of the RF signal)? If it is the 'subharmonic and multiples
thereof" specification applies.
Press the [CW] key to view the CW frequency in the ENTRY DISPLAY.
c. If the spurious response in question does not meet one of the above criteria, the 'non-
harmonically related" specification applies.
7. Repeat steps 4 through 7 at any frequency of interest within this frequency band.
8. Press the DUT's [STOPFREQI key and enter the stop frequency for the next frequency band.
Press the [STARTFREQI key and enter the start frequency for the next frequency band. Repeat
steps 3 through 8 until all DUT frequency bands have been tested up to 22 GHz (for HP 8340B), or
20 GHz (for HP 8341 B).
HP 8340B/41B
(10 MHz to 20 0Hz
NOTE
NOTE
HP 8340B only)
-
HP 8341 B)
-
Performance Tests 4-39/4-40