If I may direct you to www.quartzlock.com and the online catalog, you will see specifications of the small H Masers. We have both in use. Nicholai Demidov's paper at EFTF 2012 showed real results of a number of active H maser's with drifts down to E-17 levels One might ask when some benefit will be seen from all the trapped ion and optical clock work over the last 20 years ? cw a €160k AHM.
We used a NIST system here for months to look at our AHM drift / offset, but our maser was below the noise level of the NIST system, so we just had <E-12 results Why AHM performance better, look at the physics package drawings in the catalog to see the multiple ovens, magnetic screens etc, but mostly AHM Q=40,000, where PHM Q=10,000. Modern AHM have inbuilt autonomous autotuning to virtually illuminate drift. Incidentally, an oral paper by a NIST or USNO in Switzerland at EFTF many years ago reminded us all that any greater performance will have to account for lunar phases, earth tides, sea level change 2 x day, local magnetic anomalies 9the least of one's worries and in any event, what is the application / relevance of these levels of performance. of course the advancement of knowledge is one, but hugely expensive. Open question: We regularly measure stability noise floors to E-17 levels. What other parameter can be measured with greater resolution ? Clive Green G3OPX/MM Clive Green CEO Quartzlock + Gothic, Plymouth Road, Totnes, Devon. TQ9 5LH England (: +44 (0) 1803 862 062 7: +44 (0) 1803 867 962 š: cgr...@quartzlock.com ü: www.quartzlock.com Skype: clive.green.skype Messenger: cgr...@quartzlock.com Registered office: Gothic, Plymouth Road, Totnes, Devon. TQ9 5LH England Registered in England P Think Environment, print only if necessary. This is an e-mail from Quartzlock (UK) Limited, its contents (including all attachments) and any files transmitted with it are confidential and intended solely for the individual(s) to which it is addressed and may also be privileged. It may not be copied or printed by anyone other than the addressee and may not be disclosed or distributed in any way. If you have received this e-mail in error please inform Quartzlock (UK) Limited and delete it from your mailbox or any other storage devices. Although this e-mail and any attachments are believed to be free of any virus or other defects which might affect any computer or IT system into which they are received, no responsibility is accepted by Quartzlock (UK) Limited or any of its directors, staff or associated businesses or contacts for any loss or damage arising in any way from the receipt or use thereof. Opinions, conclusions and other information expressed in this message are not given or endorsed by Quartzlock (UK) Limited unless otherwise indicated by an authorised representative independent of this message. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
