681XXC OM 6-5Error Message Description/Remarks
Error111
FineLoop Osc Failed Indicatesone or more of the oscillators within the fine loop is not phase-locked. The
681XXCis still operable but the accuracy and stability of frequency outputs are
greatlyreduced.
Error112
CoarseLoop Osc Failed Indicatesthe coarse loop oscillator is not phase-locked. The 681XXC is still
operablebut the accuracy and stability of the frequency outputs are greatly
reduced.
Error113
YigLoop Osc Failed Indicatesthe YIG loop is not phase-locked. The 681XXC is still operable but the ac -
curacyand stability of the frequency outputs are greatly reduced.
Error114
DownConverter LO not Locked Indicatesthe local oscillator in the down converter assembly is not phase-locked.
The681XXC is still operable but the accuracy and stability of frequency outputs be -
low2 GHz is greatly reduced.
Error115
NotLocked Indicator Failed Indicatesfailure of the not phase-locked indicator circuit. The 681XXC is still
operablebut an error message will not appear on the data display when the output
frequencyis not phase-locked.
Error116
FMLoop Gain Check Failed IndicatesFM loop has failed or the loop gain is out of tolerance. The 681XXC is still
operablebut frequency accuracy and stability are degraded.
Error117
LinearizerCheck Failed Indicatesa failure of the Linearizer DAC on the A12 PCB. The 681XXC is still
operablebut frequency accuracy of the RF output is degraded.
Error118
SwitchpointDAC Failed Indicatesa failure of the Switchpoint DAC on the A12 PCB. The 681XXC will not
produceanalog sweeps but should operate normally in CW and step sweep modes.
Error119
CenterFrequency Circuits
Failed
Indicatesa failure of the center frequency circuitry on the A12 PCB. DoNot
Attemptto Operate! Refer the instrument to a qualified service technician.
Error120-
Delta-FCircuits Failed Indicatesa failure of the DF Width DAC on the A12 PCB. The 681XXC will not
generateDF analog sweeps but should produce DF step sweeps.
Error121
UnleveledIndicator Failed Indicatesfailure of the not leveled detector circuitry on the A10 PCB. The 681XXC
isstill operable but a warning message will not appear when the RF output goes
unleveled.
Error122
LevelReference Failed Indicates a failure of the level reference circuitry on the A10 PCB. Use caution and
alwaysdetermine the output power level when operating the 681XXC in this condi -
tion.
Error123
DetectorLog Amp Failed Indicatesafailure of the level detector log amplifier circuitry on the A10 PCB. Use
cautionand always determine the output power level when operating the 681XXC
inthis condition.
Error124
FullBand Unlocked and Unleveled Indicatesa failure of both YIG-tuned oscillators. DoNot Attempt to Operate! Refer
theinstrument to a qualified service techician.
Table6-1. Self-TestError Messages (2 of 4)
OPERATOR ERROR AND WARNING/
MAINTENANCE STATUS MESSAGES