From Nicholas.Dando at ga.gov.au Mon Dec 16 19:57:11 2013 From: Nicholas.Dando at ga.gov.au (Nicholas.Dando at ga.gov.au) Date: Tue, 17 Dec 2013 14:57:11 +1100 Subject: [IGSSTATION-5620] FW: HOB2 external frequency H-maser swapover [SEC=UNCLASSIFIED] Message-ID: <60D02F9C526B7F48B21941A0882AFD337E89495544@EXCCR01.agso.gov.au> ****************************************************************************** Site ID : HOB2 DOMES: 50116M004 Location: Mt Pleasant Observatory, Hobart, Tasmania Australia ****************************************************************************** Dear colleagues, Please be advised of some changes to the external frequency of the HOB2 receiver in the previous few weeks. 2013-11-14T01:10Z NASA H-maser > non maser oscillator for a few hours > NASA H-maser 2013-12-02T01:00Z NASA H-maser > Vremya-CH V1005A H-maser It is anticipated the HOB2 receiver will be returned to the NASA H-maser sometime in the future. Once we have updated information we will make the necessary changes to the site log. Nicholas Dando National Geospatial Reference Systems Minerals and Natural Hazards Division | GEOSCIENCE AUSTRALIA ____________________________________________________________ Cnr Jerrabomberra Avenue and Hindmarsh Drive Symonston ACT GPO Box 378 Canberra ACT 2601 Australia Applying geoscience to Australia's most important challenges Dear GA, We are going to change out some vacuum pump components in the NASA H-maser here at Hobart. In preparation for this we have moved the entire Hobart observatory to the Vremya-CH V1005A (Russia) H-maser frequency standard. We did this today soon after 0100 UT on December 2nd. This would have affected your GPS receiver external oscillator connection briefly during the swap. Regards, > We were only on the non maser oscillator for a few hours. However, we > discovered that the room thermostat had failed and so we shall be > doing more work affecting the H-maser tomorrow. Since the room > temperature is not constant, frequency stability could be degraded > over periods greater than 0.5 hours. > > > On 14/11/2013 12:13: >> Hi GA, >> Our NASA maser H-maser needs some work. >> We will disconnect it and run the station from a non maser oscillator >> for a little while. This will commence around UT 0110 on 14 November >> 2013. >> >> We will keep you posted as to when it returns to H-maser freq >> standard today. >> >> Also we may need to do something similar next Monday and we will keep >> you informed of that too >> >> Regards, >> Geoscience Australia Disclaimer: This e-mail (and files transmitted with it) is intended only for the person or entity to which it is addressed. If you are not the intended recipient, then you have received this e-mail by mistake and any use, dissemination, forwarding, printing or copying of this e-mail and its file attachments is prohibited. The security of emails transmitted cannot be guaranteed; by forwarding or replying to this email, you acknowledge and accept these risks.