Agilent Technologies 8719ET Service Manual page 272

Service Key Menus and Error Messages
Service Menu - Service Features
•
DAC NUM HIGH BAND
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.
•
DAC NUM HIGH BAND
DAC numbers in the range of 2020 through 4095 to generate test port
output frequencies from 18.2 GHz to 23.2 GHz.
•
PWR DAC ON off
oscillator.This DAC is located on the A59 source interface board.
•
ALC ON off
(SM4)
PLL AUTO ON off
PLL DIAG on OFF
PLL PAUSE
MORE
10-18
This controls the amplitude of the reference
toggles the automatic leveling control (ALC) on and off.
automatically attempts to determine new pretune values
when the instrument encounters phase lock problems (for
example, "harmonic skip"). With
frequencies and voltages do not change, as when they are
attempting to determine new pretune values, so
troubleshooting the phase-locked loop circuits is more
convenient. This function may also be turned off to avoid
pretune calibration errors in applications where there is a
limited frequency response in the R (reference) channel.
For example, in a high power test application, using band
limited filters for R channel phase locking.
(SM5) displays a phase lock sequence at the beginning of each
band. This sequence normally occurs very rapidly, making
it difficult to troubleshoot phase lock problems. Switching
this mode ON slows the process down, allowing you to
inspect the steps of the phase lock sequence (pretune,
acquire, and track) by pausing at each step. The steps are
indicated on the display, along with the channel (C1 or C2)
and band number (B1 through B13).
This mode can be used with PLL PAUSE to halt the
process at any step. It can also be used with the analog bus
counter.
is used only with PLL DIAG mode.
it will continuously cycle through all steps of the phase
lock sequence.
This mode is useful for troubleshooting phase-locked loop
problems.
accesses the Service Modes More menu.
(SM2H) (8719ET/ES and 8720ET/ES) allows
(SM2H) (8722ET/ES) allows you to enter
holds it at any step of interest.
PAUSE
8719ET/20ET/22ET
8719ES/20ES/22ES
RF Network Analyzers
, the
PLL AUTO OFF
indicates that
CONT
Service Guide