By the time you get the signal from the maser through 34 km of fiber optic, what you get at the end might be not better than a decent GPSDO...
Make sure you go through your drift and jitter budget before commiting. Didier > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Scott Mace > Sent: Tuesday, November 25, 2008 1:42 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] 10 MHz over optical fiber? > > In looking at the off-the-shelf boxes, jitter seemed to vary > from ps range to tens of ns. Also, how stable is the 34km of > fiber... One of the manufacturers I looked at had a 1550nm > option, so it's probably not a stretch to get it on a 100GHz > ITU grid channel or other CWDM channel. > > Scott > > Paul Boven wrote: > > Hi everyone, > > > > In message <[EMAIL PROTECTED]>, > Marco IK1ODO > > -2 > > writes: > >> Hi all, > >> > >> I have to carry a 10 MHz standard frequency signal inside an EMC > >> screened room via fiber optic cable. > >> > >> Not willing to re-invent the wheel, do something like an optical > >> standard frequency link exist on the market? > >> I think it is possible to use standard 100MB LAN transceivers, and > >> POF. Phase noise requirements are not very stringent, and the > >> distance is in the order of some tens of meters. > > > > I'm looking into something similar: transmitting an H-Maser signal > > (probably 10MHz) over some 34km using CWDM SFPs. At first > glance this > > seems fairly uncomplicated: get some SFPs, and SFP > connector + cage. > > Use a fast opamp/differential driver to drive the transmitting SFP, > > and use a similar setup at the other end to transform the received > > data back to 50 ohm unbalanced. How feasible would such a setup be? > > Possible problems might be that a 10MHz squarewave is > simply too 'slow' > > to be transmitted by an SFP, which expects 1.25Gb/s 8/10 > encoded data. > > Another interesting question would be how much jitter/noise such a > > setup would add? > > > > Regards, Paul Boven. > > > > _______________________________________________ > > 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.