Service Guide 10-17
8719ET/20ET/22ET Service Key Menus and Error Messages
8719ES/20ES/22ES Service Menu - Service Features
RF Network Analyzers
Service Modes Menu
To access this menu, press .
allows you to control and monitor various circuits for
troubleshooting.
(SM1) tests the A13 and A14 fractional-N circuits. It allows you
to directly control and monitor the output frequency of the
fractional-N synthesizer (60 MHz to 240 MHz).
Set the instrument to CW sweep mode and then set
FRACN TUNE ON. Change frequencies with the front
panel keys or knob. The output of the A14 assembly can be
checked at A14J1 HI OUT (in high band) or A14J2 LO
OUT (in low band) with an oscilloscope, a frequency
counter, or a spectrum analyzer. Signal jumps and changes
in shape at 20 MHz and 30 MHz when tuning up in
frequency, and at 29.2 MHz and 15 MHz when tuning
down, are due to switching of the digital divider. This
mode can be used with the SRC TUNE mode as described
in Chapter 7 , “Source Troubleshooting.”
accesses the functions that allow you to adjust the source:
NOTE If the instrument displays the PHASE LOCK CAL FAILED message, use the
keys of the Source Adjustment Menu. The
relationship between DAC numbers and frequency varies between
instruments. The DAC numbers, provided in the description, and frequencies
are guidelines only.
• (SM2D) disables the source frequency tune
modes.
• tests the pretune functions of the phase lock
and source assemblies. These keys allow entry of digital data directly
into the DAC on the A11 phase lock assembly. When in this mode:
— Instrument does not attempt to phase lock.
— Residual FM increases.
• (SM2L) allows you to enter DAC numbers in
the range of 3650 through 4095 to generate test port output frequencies
from 50 MHz to 1.1 GHz.
• (SM2M) (8722ET/ES only) allows you to enter
DAC numbers in the range of 2900 through 4095 to generate test port
output frequencies from 2.3 GHz to 4.9 GHz.
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