Message-ID: <2F269D42928548669AFA4E025E6F869C@tfpc26>
From: "Giancarlo Cerretto" <g.cerretto@inrim.it>
To: "IGS mailing list" <igsstation@igscb.jpl.nasa.gov>
Subject: [IGSSTATION-3589]: IENG: UTC(IT) Master Clock (Active Hydrogen
  Maser) replacement
Date: Fri, 26 Feb 2010 16:11:43 +0100
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IGS Station Mail          26 Feb 07:12:40 PST 2010      Message Number 3589
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Author: Giancarlo Cerretto

Dear colleagues,

this message is to inform you that on 2010 February 25th (DOY 56 ; MJD
55252), the INRIM Active Hydrogen Maser used as Master Clock for the
italian realization of UTC, namely UTC(IT), has been characterized by a
serious anomaly.

For this reason, it has been decided to replace urgently such a Maser with a
further one.

In particular, the current "Kvartz CH1-75A" has been replaced with a
"Symmetricom Datum".

Due to the different operations required to perform the replacement and to
grant continuity in terms of "frequency" and "phase" with respect to the
"pre-failure" period, for the following period IENG measures have NOT to be
considered appropriate for timing purposes:

- 14.00 UTC, 2010 February 25th (DOY 56 ; MJD 52252) --->  08.40 UTC, 2010
February 26th (DOY 57 ; MJD 52253)

An updated version of the IENG "site-log" will be prepared shortly,
reporting the new "standard type" for IENG station.

I apologize for the inconvenience this setback may cause.

For any question, doubt or suggestion, please do not hesitate to contact me.

Kind regards,

Giancarlo.

==========================================
Giancarlo Cerretto
Time and Frequency Laboratory
Istituto Nazionale di Ricerca Metrologica (I.N.RI.M.)
Strada delle Cacce 91, 10135 Torino, Italy
http://www.inrim.it/
Phone:   +39 011 3919 239/349;  Fax:  +39 011 3919 259
E-mail:    g.cerretto@inrim.it
==========================================