How good or bad is the 10811 and which one on ebay is a better choice ? I am looking for a very goo 5 MHz crystal oscillator with documentation . Thanks, Ulrich N1UL In a message dated 8/8/2015 7:16:37 P.M. Eastern Daylight Time, kb...@n1k.org writes:
Hi Ok, so John’s observation was the correct one. The data we are looking at is *not* the performance of the OCXO’s but the strange behavior of the counter at short ADEV Tau’s. Sorry for my bashing your poor 10811. Bob > On Aug 8, 2015, at 12:25 PM, tim...@timeok.it wrote: > > Hi all, > > I try to ansver to all you: > > Luciano, how was the blue trace taken? Is this from your DMTD project? If so, it's looking promising. > The green and magenta traces are definitely in the right ballpark for measurements on a 5370-class counter. At 3E-11 @ t=12s the magenta trace is optimistic but not outrageously so, while the green trace looks exactly like I'd expect for a typical 10811 measured on a 5370. The observed noise is due entirely to the counter until about t=200s. We see a glimpse of the 10811's typical ADEV at about 250 seconds, just before either drift or ADEV uncertainty causes the trace to turn upwards. A longer run would be needed to distinguish between these two situations. > > -- john, KE5FX > Miles Design LLC > > r: no, all the measurements are taken using an HP53132A in frequency mode. The difference can be the gate time. Using 1 second the resolution is lower than using 2 Second that permit the max counter resolution. > > Hi > > Well an un-stated assumption of mine was that they all came from the same measurement system and that it > had the same floor under all circumstances…. > > Bob > > r: all the measurements are under the same conditions except for the gate time of the counter. > > Hi Luciano, > > Can you give me the link to your ADEV posting image about 10811 vs 105 oscillators? I had it and now can't seem to find it. I wanted to look at your plots as I read John Miles' comments. Many thanks. > > I have two very high performing HP10811-60109 OCXO units which I got from Corby. > > Many thanks. > > Jim Robbins > N1JR > > r: Jim, I will load soon some files on my site. The 105B I have is a fantastic exception, unfortunately it have a defect, may be a bad solder inside cause randomly a phase jump and return to the original phase trend, so all The long term ADEV are distorted by this problem I have to fix. > > Tom VB, i will do all the cross measurements on 10811, 00105 and rubidium I have and i will upload they but I need time to do this. > Unfortunately I have only the HP53132A as TIC and my best reference are four HP5065A. I normally use the counter function because the TI function on 1 PPS have 100 time less resolution. > Will be interesting doing also the Phase noise tests. I will do it. > please see: http://www.timeok.it/files/time_and_frequency_house_standard_201r.pdf > > Luciano > www.timeok.it > > > > > > On Sat 08/08/15 02:23 , Bob Camp <kb...@n1k.org> wrote: > >> Hi >> >> Well an un-stated assumption of mine was that they all came from the same >> measurement system and that it >> had the same floor under all circumstances…. >> >> Bob >> >>> On Aug 7, 2015, at 5:21 PM, John Miles wrote: >>> >>>> Hi >>>> >>>> If that data is correct, then the 10811 you have is defective. >>>> Bob >>> >>> Well... some of the data is reasonable for a scenario where a counter is >> being used to measure OCXOs. >>> >>> Looking at the ADEV plot, I'd say the blue trace (HP105B vs 5065A) is >> the most questionable one if it came from a standalone TIC or frequency >> counter, because 7E-12 @ t=1s isn't achievable with most counters under >> most circumstances. A Wavecrest box can measure at that level if it's set >> up _perfectly_ to take bursts of 100+ wrap-free averages within a small >> fraction of the t0 interval. It might also be doable with an HP 5370A/B >> under similar conditions, but I'd have less confidence that the averaging >> isn't distorting the measurement. So while It looks like a valid >> measurement of an OCXO with some minor crosstalk or other external >> interference, that may just be a coincidence. >>> >>> Luciano, how was the blue trace taken? Is this from your DMTD project? >> If so, it's looking promising. >>> >>> The green and magenta traces are definitely in the right ballpark for >> measurements on a 5370-class counter. At 3E-11 @ t=12s the magenta trace is >> optimistic but not outrageously so, while the green trace looks exactly >> like I'd expect for a typical 10811 measured on a 5370. The observed noise >> is due entirely to the counter until about t=200s. We see a glimpse of the >> 10811's typical ADEV at about 250 seconds, just before either drift or ADEV >> uncertainty causes the trace to turn upwards. A longer run would be needed >> to distinguish between these two situations. >>> >>> -- john, KE5FX >>> Miles Design LLC >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts [1] >>> 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 [2] >> and follow the instructions there. >> >> >> >> Links: >> ------ >> [1] >> http://webmail.timeok.it/parse.php?redirect=https://www.febo.com/cgi-bin/ma >> ilman/listinfo/time-nuts[2] >> http://webmail.timeok.it/parse.php?redirect=https://www.febo.com/cgi-bin/ma >> ilman/listinfo/time-nuts >> > Message sent via Atmail Open - http://atmail.org/ > _______________________________________________ > 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. _______________________________________________ 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.