Troubleshooting
Troubleshooting Non-Harmonic Spurious
1-65
Troubleshooting Non-Harmonic Spurious
There are nine different groupings a spur can fall into. The grouping determines what assembly is most likely
generating the spur. The procedure for troubleshooting spurs is to identify the grouping based on failing a
performance test, checking for loose or broken cables or castings, and replacing the assembly.
Table 1-42
Mixing Spurs These spurs are generatedby the mixing products ofthe
RF and IF signals on the A8 Output. The instrument is
tuned to a frequency in the Heterodyne-Band (250 kHz
to 250 MHz) to measure these spurs.
Power Supply Spurs These spurs are generated by the power supply
switching at a 100 kHz rate. If the test fails for these
spurs, change A19 Power Supply.
Offset Reference Spurs These spurs are generated by the 10 MHz frequency
reference on the A7 Reference.
Clock Spurs Two clocks on the A11 Pulse/Analog Modulation
Generator generate these spurs. The first clock is
33.554432 MHz and is used by the numeric synthesizer.
The second clock is 100 MHz and is used by the internal
pulse generator.
RF and LO Feedthrough Spurs When the instrument is tuned to a Heterodyne Band
(250 kHz to 250 MHz) frequency, the RF and LO feeds
through from the mixer on the A8 Output generates
spurs on the RF output.
Frac-N Feedthrough These spurs are generated by the Frac-N frequency
coupling onto the low-band signal as it leaves the A6
Frac-N. The spurs then appear at the Frac-N frequency
at the RF output.
Sampler Spurs These spurs are generated on the A5 Sampler by the
sampler LO and IF frequencies.
Frac-N 250 MHz Crossing Spurs These spurs are generated by either the A5 Sampler, A6
Frac-N, or A7 Reference. They occur when a harmonic of
the Frac-N frequency equals a harmonic of 250 MHz.
The spurs are measured in highband at 133 kHz offset
from the CW frequency.
IF 250 MHz Crossing Spurs These spurs are generated on the A5 Sampler. They are
caused by harmonics of the A5 Sampler IF. The spurs
are measured in highband at 133 kHz offset from the
CW frequency.
To Next Page
Loading...
Need help?
General
