Hi Bill -- I haven't done any more testing, but I'm pretty convinced that there is something wrong with my hardware, though the monitoring software didn't indicate any obvious problems. I need to go back and revisit, but due to a bunch of health problems earlier this year (now just about over with), I haven't gotten very much done in the basement for a while.
John ---- Bill Hawkins wrote: > John, > > Back in February, you looked at the Lucent GPSDO and declared it the > worst you'd seen. > > Did you ever update that opinion? Is the complete set for $400 not worth > buying if you > have a pair of Z3801s that perform some heroic jumps? This is just a > hobby, not long > baseline interferometry. > > Bill Hawkins > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of John Ackermann N8UR > Sent: Sunday, February 03, 2008 7:18 PM > To: Discussion of precise time and frequency measurement > Subject: [time-nuts] Lucent RFTG-XO performance... > > Has anyone here done any performance measurements of the Lucent RFTG-XO > unit? I am testing one now and getting extremely unimpressive results, > and wonder if anyone else has looked closely at these things. > > What I'm seeing is almost flat ADEV in the low to mid 10s from 1 second > out to 40,000 seconds. At 100,000 seconds, it drops to the high 11s.* > To this point I haven't seen anything that looks like the normal GPSDO > characteristic of a rapid ADEV improvement from around 1000 seconds or > so. In fact, this is about the flattest ADEV plot I've ever seen from > an oscillator. > > The frequency difference plot** shows a bang-bang effect of about > 1.6x10e-9 over the course of a few minutes. This seems to go on > continuously (at least over the 4 days of data so far). That certainly > explains the mediocre ADEV performance. > > The thing does appear to be locked to GPS, but if my unit is working > properly, it's about the worst performing GPSDO I've seen. > > By the way -- to do this test, I started with both the -XO and -RB units > online and interconnected the way they were supposed to be. After a > couple of days of operation, I pulled the interconnect cable and the -RB > went off line, while the -XO came on. I then started data collection. > After I'm satisfied with the amount of XO data I have, I'll reconnect > the cable and do the same test on the -RB side. The full set of plots > is at http://www.febo.com/pages/oscillators/rftg/ and will be updated as > I get more data. > > John > > * http://www.febo.com/pages/oscillators/rftg/rftg-xo_cs1-adevplot.png > ** http://www.febo.com/pages/oscillators/rftg/rftg-xo_cs1-freqdiff.png > > _______________________________________________ > time-nuts mailing list -- [email protected] To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
