I just calculated the frequency offset. I count 5 crosses, while jumping down to 200 ns, I guess, 1 cross equals 10 min? So let's say the jump lasts 60 min (= T jump). When we want to calculate the frequency offset out of a phase jump, we have to differentiate the phase and we should achieve
delta f = delta phase / delta T delta f = (delta t / T period) / T jump delta f = (200ns / 100ns) / 60 min delta f = 0,55 mHz (milli, not Mega!) What precision / stability do you demand? Volker Am 28.02.2013 00:47, schrieb saidj...@aol.com:
Hello Claude, that gap is a classic crystal jump. It could be caused by the crystal changing frequency by itself, or by being hit with e.g. gamma particles etc. Could also have been instigated by vibration or shock to the unit. You should be seeing 6+ sats at all times though, your plot shows you sometimes seem to see 2 or 3 sats only? Maybe a better antenna position would help the stability of that unit. Nothing to worry about if it doesn't happen regularly. Enjoy, bye, Said In a message dated 2/27/2013 15:18:51 Pacific Standard Time, lab...@yahoo.fr writes: Hello, This is my first message here although I read this list for a few weeks. I bought a Z3805A/58503A frequency receiver and I didn't notice on the pictures that the model number was not written on the front panel. It's not important but is there a reason for that, if you know ? The item : http://cgi.ebay.fr/ws/eBayISAPI.dll?ViewItem&item=251226027893 I log some parameters of the receiver and today I notice a "gap" in the frequency. Picture : http://uppix.net/e/2/4/cf39ac772e5a69fc616f5cf30f208.png I have a Rubidium and I measure it's frequency with a 5334B counter locked to the GPS, and I can see the "gap" too : http://uppix.net/f/b/a/d86c2737ad135264e4a2b78e503d5.png measurements are with Gate Time of 10s, 60s and 100s, Do you know why this happens and how to prevent this behaviour ? Thanks for yours advices Claude _______________________________________________ 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.
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