Tektronix CSA 803C Marine Radio User Manual


 
Other Troubleshooting
Maintenance
6Ć106
Table 6Ć18 lists the time base calibration errors that can appear on the
CSA 803A screen and the suspected faulty FRUs that cause the error. The
FRUs are listed in the order of most to least likely source of the error.
Time base calibration errors whose error codes are greater than 100 have
two different forms, depending on when the error occurs. If the error occurs
during powerĆon then the message will say:
Time base calibration failed at power up: 2XX
where 2XX is the error code.
If the error occurs at any other time, then the message will say:
Time base calibration failed: 1XX
where 1XX is the error code.
Calibration data to enhance the time interpolator linearity is stored in NVRAM
on the Time Base/Controller board. If this NVRAM fails, a T1331 error occurs
during powerĆon diagnostics. The values are written at the factory with the
GPIB command CALCORRECTION.
CALCORRECTION
<ui>
:
N
where
<ui>
= 0. . .32 and
N
= -128. . .+127
CAUTION
The calibration enhancement values are set at time of manufacture.
There is no query form of this command. Do NOT reset these
values. If a T1331 failure occurs during extended powerĆon diagĆ
nostics or you suspect a time interpolator error, contact Tektronix
factory service.
A T1331 failure causes all N values in the 33 ui locations to be reset to zero.
The oscilloscope will still run, but with decreased accuracy in the time interĆ
polator linearity. Resetting NVRAM with the Teksecure feature does not affect
the Time Base/Controller board NVRAM.
Time Base
Calibration Errors