Hi: Sorry for the bad links, here are good ones: Today's plot = http://www.pacificsites.com/~brooke/pdf/sn1013_850_Drift2.pdf s/n 1227 29 Apr 2005 plot = http://www.pacificsites.com/~brooke/pdf/Cs_Drift0429.pdf
Brooke Brooke Clarke wrote: >Hi: > >A year ago I took apart the FTS4060 that was DOA (s/n 1013) because of >rough shipping and used it to figure out most of the interconnect >wiring. A few months ago I put it back together with the thought of >selling it as a parts unit. But first powered it up and found that it >now locked and seemed to be working so tried to set the C-field. > >For the last couple of weeks it has shown a parabolic plot like s/n >1227, although this time the polarity is opposite that of s/n 1227 which >also showed drift, but that may be a setup difference. A plot of s/n >1227 is at: file:///C:/Webdocs/pdf/Cs_Drift0429.pdf >The equation for s/n 1013 is: > y = 2.7943x2 - 302.64x + 8969.4 and the quality of fit is >R2 = 0.9088. The x-axis is in days and the y-axis is in ns. >The first derivative of the equation has a first term of 2 * 2.7943 * x >ns/day or +5.3E-14 seconds/seconds drift rate. >Today's plot is at: file:///C:/Webdocs/pdf/sn1013_850_Drift2.pdf > >The current setup is: >SR620 time interval counter doing 500 averages (500 seconds = 8 1/3 >minutes). >Start from Motorola M12+T (9 ns jitter). >Stop from FTS4060 1 MHz output. >Manually enter into spreadsheet date and time of reading (usually not on >the 8 1/3 minute change, just a random time) and counter value. > >For most of the test the SR620 was using it's internal oscillator and >just recently I changed it to the PRS10 external standard but that does >not seem to have made any difference. > >Is there something I'm doing wrong that would cause apparent drift? > >Thanks for any thoughts, > >Brooke Clarke, N6GCE > > > -- w/Java http://www.PRC68.com w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml http://www.precisionclock.com _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
