Microsemi Maser frequency standard in Green Bank

[FDG: August 2018; revised Oct 2019]

New maser frequency standard installed in Green Bank August 23, 2018 by Bryan Owings of Microsemi. Maser model MHM-2010, serial no: 0100000345

Related Links
Masers Performance History ST Maser Adjustments Log 1pps cable delays All Timing Logs Recent Timing plots
Time logging system explained Notes on implementing a leap second Implementing UT1 Corrections Time Knowledge

Reference:
  • Users Guide and Reference Manual.
  • Start Up Manual.
  • How to adjust the maser.
  • Maser tutorial presentation.
  • Maser monitor data, since installation.
  • Timing data Jan to Sep 2019

    Site Time inputs, revised Aug-Sep 2018

    The site time monitors have been updated as follows:
    1pps input signal
    X0 Site 1Hz (from TRAK clock)
    X1 CNS_GPS1 (1pps)
    X2 CNS2018 (new CNS GPS receiver)
    X3 CNS_GPS2 (1/100pps)
    X4 MicroSem (1pps from new maser)
    Y0 GBT_VLBA
    Y1 RA (round trip to 140')
    Y2 GBTRtn (round trip to GBT)
    Note: the synthesizer can be in internal or external mode depending on the toggle switch on the front panel.
  • In internal mode, the synthesizer is set to the value in the thumbwheel switches.
  • In external mode, the synthesizer is set by the laptop from the synthesizer screen.
  • To use the drift correction, put the values in the synthesizer screen on the laptop and use external mode.

    Log of adjustments and Events

  • 2018 Aug 23: Maser model MHM-2010 installed.
  • Initial synthesizer setting: 57516839098
    Date Synthesizer Delta Synth Offset MSM to GPS Drift Comments
    2018 Aug 23 5751.6839098 0 1022ns 0 Initial synthesizer setting
    2018 Nov 29 5751.6837236 -1862 2075ns 0 Adjust synthesizer by -1862 to match GPS rate. New Setting: 57516837236
    2018 Nov 29 ditto 1115ns 0 Synchronize 1 pps to Site 1Hz
    2018 Dec 6 5751.6840960 +3724 1244 0 Adjust synthesizer to put correction in with opposite sign to what was done Nov 29
    2019 Apr 23 5751.6837960 -3000 -1223 0 Adjust synthesizer to match GPS rate.
    2019 May 15 5751.6835560 -2400 -1533 0 Adjust synthesizer to match GPS rate.
    2019 Sep 24 5751.6835560 +52 Put +52 dds/day drift correction in synthesizer screen on laptop; changed synth mode to external.
    2019 Sep 25 5751.6834500 -1060 -4300 -52 Change sign of drift correction, and decrease synthesizer by 1060.
    2019 Sep 26 5751.6833000 -1446 -4380 -52 Another decrease of synthesizer to start to approximate GPS rate.
    2019 Sep 27 5751.6831500 -1500 -4400 -52 Yet another decrease of synthesizer to approximate GPS rate.
    2019 Sep 30 5751.6830000 -1500 -4474 -52 Yet another decrease of synthesizer to approximate GPS rate.
    2019 Oct 02 5751.6827597 -2300 -4505 -52 Still another decrease of synthesizer to approximate GPS rate.
    2019 Dec 06 5751.6824217 0 -4759 -74 Adjust drift correction by -22 counts.
    2019 Dec 12 5751.6822609 -1175 ~ 0 -74 Decrease synthesizer by 1175 counts; sync 1pps to GPS.