On Sat, 22 Dec 2007 22:02:49 +1300, you wrote: >swingbyte wrote: >> Hi everybody, >> I mentioned some time ago that I had an Ru 10MHz source and I would like >> to calibrate it. I have an hp 5335 counter and a Jupiter GPS with 10kHz >> output. I was wondering if I could use the Ru 10MHz as and external >> clock for the 5335 and then measure the frequency of the 10kHz gps >> locked signal and adjust the Ru to read exactly 10kHz? If I let the >> 5335 average the frequency input it will display 12 digits - how many of >> those are reliable I'm not sure but it seems that this may be an easy >> way for me to check the Ru. >> Is this a viable method or am I missing something - I haven't done a lot >> of research into the time keeping world yet. >> Also, the model Ru I have is the Efratrom frk-h with external frequency >> control. I have had a quick read of the manual but can't find any >> information on how this works. I was thinking this might enable me to >> discipline the Ru to GPS - does anyone know how this works? >> >> Thanks for your help >> Happy holidays >> >> Tim >> >> >Tim > >The biggest problem with your proposed measurement scheme is that the >10kHz signal is no more stable than the PPS output. >The 10kHz output is phase jerked every second to realign it with the UTC >second. >This behaviour is clearly documented in the receiver datasheet.
All the docs I've seen are rather functional in their description, and short of detail. I was curious how exactly the 10KHz is generated, how it's "aligned", and the precision/position of each rising edge - anyone got any info on this? Thanks, Angus. >Thus to reduce the measurement error due to this instability to better >than 1E-10 or less the counter gate time will need to be around 1000 >seconds or more. >Adjustment to better than 1E-10 will be somewhat problematic not to say >time consuming. >Fortunately the 5335A maximum gate time is 1E7 seconds or about 4 >months, so this may actually be possible. > >Bruce > >_______________________________________________ >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. _______________________________________________ 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.