Nautel XR12 Operation And Maintenance Manual

Also see for XR12: Installation manual Troubleshooting manual Preinstallation manual

XR12 Operations and Maintenance Manual Operating the transmitterPage 2-18 Issue 3.1 2013-03-1430-Day Drift Estimation1. Set the XR12’s clock (see “Setting the clock” on page 2-16) according to a selectedindependent time standard.2. After 30 days, compare the XR12’s clock time to the same independent time standard. Notethe time difference.3. In the Calibrate Clock page, adjust the Current RTC Calibration value until the Delta 30-dayCorrection time is as close as possible to the difference noted in Step 2. NOTE: If theXR12’s clock gained time on the standard, the Delta 30-day Correction value should benegative; If the XR12’s clock lost time on the standard, the Delta 30-day Correction valueshould be positive.4. Press the Save button to store the calibration value.5. Reset the XR12’s clock according to the time standard.6. The calibration is complete.RTC Frequency Measurement1. Connect a frequency counter, capable of measuring 512 Hz within 0.001 Hz, to a nominal512 Hz, 5 V CMOS square-wave on TP51 of the control display PWB (A1A1). Note themeasured frequency.2. In the Calibrate Clock page, adjust the Current RTC Calibration value until the EstimatedFT Frequency value is as close as possible to the measured frequency in Step 1.3. Press the Save button to store the calibration value.4. Reset the XR12’s clock (see “Setting the clock” on page 2-16) according to a selectedindependent time standard.5. The calibration is complete.