Error Message
Description/Remarks
Error 112
Coarse Loop Osc Failed
Indicates the coarse loop oscillator is not phase-locked. The 681XXB is still
operable but the accuracy and stability of the frequency outputs are greatly
reduced.
Error 113
Yig Loop Osc Failed
Indicates the YIG loop is not phase-locked. The 681XXB is still operable but the
accuracy and stability of the frequency outputs are greatly reduced.
Error 114
Down Converter LO not Locked
Indicates the local oscillator in the down converter assembly is not phase-locked.
The 681XXB is still operable but the accuracy and stability of frequency outputs
below 2 GHz is greatly reduced.
Error 115
Not Locked Indicator Failed
Indicates failure of the not phase-locked indicator circuit. The 681XXB is still
operable but an error message will not appear on the data display when the output
frequency is not phase-locked.
Error 116
FM Loop Gain Check Failed
Indicates FM loop has failed or the loop gain is out of tolerance. The 681XXB is
still operable but frequency accuracy and stability are degraded.
Error 117
Linearizer Check Failed
Indicates a failure of the Linearizer DAC on the A12 PCB. The 681XXB is still
operable but frequency accuracy of the RF output is degraded.
Error 118
Switchpoint DAC Failed
Indicates a failure of the Switchpoint DAC on the A12 PCB. The 681XXB will not
produce analog sweeps but should operate normally in CW and step sweep
modes.
Error 119
Center Frequency Circuits
Failed
Indicates a failure of the center frequency circuitry on the A12 PCB. Do Not
Attempt to Operate! Refer the instrument to a qualified service technician.
Error 120-
Delta-F Circuits Failed
Indicates a failure of the
∆
F Width DAC on the A12 PCB. The 681XXB will not
generate
∆
F analog sweeps but should produce
∆
F step sweeps.
Error 121
Unleveled Indicator Failed
Indicates failure of the not leveled detector circuitry on the A10 PCB. The 681XXB
is still operable but a warning message will not appear when the RF output goes
unleveled.
Error 122
Level Reference Failed
Indicates a failure of the level reference circuitry on the A10 PCB. Use caution and
always determine the output power level when operating the 681XXB in this
condition.
Error 123
Detector Log Amp Failed
Indicates a failure of the level detector log amplifier circuitry on the A10 PCB. Use
caution and always determine the output power level when operating the 681XXB
in this condition.
Error 124
Full Band Unlocked and Unleveled
Indicates a failure of both YIG-tuned oscillators. Do Not Attempt to Operate!
Refer the instrument to a qualified service techician.
Error 125
8.4 – 20 GHz Unlocked and
Unleveled
Indicates a failure of the 8.4 to 20 GHz YIG-tuned oscillator. Do Not Attempt to
Operate! Refer the instrument to a qualified service techician.
Table 6-1.
Self-Test Error Messages (2 of 4)
OPERATOR
ERROR AND WARNING/
MAINTENANCE
STATUS MESSAGES
681XXB OM
6-5
Changed: November 1995
