78418701 2024 065 13:00 1 06.01 Changes made to signal cable routing on the start and the stop lines. The system delay has changed due to that. 
78418701 2022 277 14:00 2 09 Former GPS receiver HP-58503A was replaced by Meinberg M1000. 
78418701 2021 363 16:00 1 6 Changes made to signal cable routing from detectors to event timer for the start diode as well as the primary (SPAD) and secondary (PMT) chain. The system delay has changed due to that on both lines. 
78418701 2020 352 12:00 2 8.01 Target Distance Update due to filter stack change. The stack is inserted during calibration to adjust the signal rate. The Calibration Target Distance was changed from 6926 to 6952 ps to account for changes of the used glasses. 
78418701 2020 337 16:00 1 5.03 Start diode signal discriminator/inverter exchanged with upgraded model of same type; trigger threshold reoptimized which changed systrem delay; trigger level set to 40 % of amplitude while pre and post pulses are at 17 % max 
78418701 2020 293 11:00 2 09.01 GPS receiver antenna delay of 153 ns reimplemented 
78418701 2020 079 16:00 2 09.01 GPS receiver lost antenna delay of 153 ns 
78418701 2018 227 12:00 3 6.01 SPAD replaced PMT as primary detector in operation 
78418701 2017 062 12:00 2 06.01 A033-ET Event Timer replacing A032-ET 
78418701 2016 362 16:00 0 04.01 New daylight filter with higher peak transmission inserted 
78418701 2016 175 12:00 1 05.02 Pump diode module for regenerative amplifier exchanged; 10 dB attenuator re-inserted into start channel (change in calibration mean value) 
78418701 2016 145 14:00 0 04.01 Optical components of telescopes cleaned (negative achromat Tx, entrance window and coupling mirror Rx) 
78418701 2016 083 12:00 1 05.02 Repaired pump diode for external amplifier and new coupling fibre installed, maximum output power 530 mW 
78418701 2016 056 17:00 1 05.02 Pump diode for external amplifier and coupling fibre failed, laser operations continued with minimum output power (50 mW) 
78418701 2016 033 10:00 1 05.02 Repaired HV power supply for Pockels cell inserted, operations resumed 
78418701 2016 018 06:00 1 05.02 HV power supply for Pockels cell failed, tracking suspended 
78418701 2015 296 10:00 0 04.01 Interpolator unit in Rx azimuth axis replaced, tracking resumed 
78418701 2015 291 20:00 0 04.01 Interpolator unit in Rx azimuth axis faulty, tracking suspended 
78418701 2015 204 10:00 1 05.02 Drop in start photodiode amplitude, 10 dB attenuater removed from start channel (change in target mean value) 
78418701 2014 246 08:00 0 05.02 Controller and coupling fibre exchanged, operations resumed with nominal output power 
78418701 2014 218 09:00 0 05.02 Controller of oscillator stage failed, station operations interrupted 
78418701 2014 125 14:00 2 05.02 Coupling fibre for final amplifier stage broken, output reduced to 40 mW average power 
78418701 2013 264 16:00 0 04.01 Azimuth encoder of Tx telescope exchanged 
78418701 2013 145 12:00 1 04.01 Narrowband daylight filter and wideband (3 nm) nighttime filter selectable for signal optimization 
78418701 2012 341 16:00 0 05.02 Mating and de-mating of laser control cables to restore proper TEC operation 
78418701 2012 270 16:00 2 06.01 Faulty PMT H5320 replaced by spare unit of same type 
78418701 2012 089 12:00 2 05.02 Experimental start pulse converter removed 
78418701 2012 088 12:00 2 05.02 Start pulse converter with constant fraction properties inserted for test 
78418701 2012 039 09:00 2 06.01 PMT operational voltage raised from 1600 to 1700 V 
78418701 2012 011 12:00 0 05.02 Coupling mirror inside the laser replaced by 25-mm HR type 
78418701 2011 314 12:00 2 05.02 Too high sensitivity of start pulse converter detected, 10 dB attenuator inserted 
78418701 2011 242 12:00 3 05.02 kHz Nd:YVO laser replacing 10 Hz Nd:YAG system 
78418701 2011 242 12:00 2 06.01 A032-ET Event Timer replacing A031-ET 
78418701 2011 242 12:00 3 06.02 MPD-1CTC SPAD replacing AD230 SPAD 
78418701 2008 300 00:00 1 04.01 Daylight filter replaced by same type and FWHM 
78418701 2004 050 00:00 2 06.01 A031 Event timer replacing SR620 time interval counter 
78418701 2003 150 00:00 1 04.01 Daylight filter (0.4 nm FWHM) introduced