Dear colleagues When I lately visited the research facility where I had worked in the 80ies*) I was told that the local timescale is still generated by the two BVA oscillators I had installed back then. One is free running and the other one is daily corrected against GPS time-scale. (The place is also fundamental GPS station of Swiss Federal Topography). I havent't discussed this further with my colleagues - it was a party and not a meeting on technology...
As luck would have it, I was called a month later for a basement clearing at Swisscom and found myself unexpectedly in possession of four time distribution mainframes by Oscilloquartz S.A.! Of course, I immediately set to open the PLL-module of one to check the type of OCXO - it was a 8600 var 02 serial 743! One of the units is a 5540 model containing a digital PLL and 3 DMTD phase comparators. Unsteered, it seems to be running with a daily drift well below 1e-11. I plan to keep this one and sell the other units (1987 model), which are of analog PLL design but have splitters and amplifiers for 2.048/5 and 10 MHz. All units have double power supplies for AC and DC backup. I measured a bare 8600 out of one of the latter units against the beforementioned 5540 output; also compared it with a GPS-disciplined GPSTM unit by Trimble. Some pics of the equipment and preliminary plots can be seen at the link **) below. I will sell - preferrably over eBay. Just email me in case you are interested. Regards Paul Kloeckler *) Zimmerwald Laser Ranging Station ZIMLAT by AIUB http://www.aiub.unibe.ch/ **) bare BVA http://www.corallinks.com/tmbroker/detail1.asp?id=107 F3 timing unit: http://www.corallinks.com/tmbroker/detail1.asp?id=108 _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
