Yes, highly recommended the differential line approach. On Thu, Jun 14, 2012 at 6:38 PM, Chris Albertson <[email protected]>wrote:
> On Thu, Jun 14, 2012 at 3:59 AM, <[email protected]> wrote: > > Acrually the PPS output has very low impedance, so you can probably load > it with 5 instruments, each with 50 termination. > > My problem with PPS distribution was the fast raise time got "smeared" > by the long cable. Lots of guesses about why. Could be reflections > off the end, capacitance in the cable. The problem is that I want > WAY under 1 microsecond level performance out of a PPS signal. The > trouble is that the PPS is a single ended signal and the leading edge > is defined by some voltage threshold. So it is sensitive to noise. > Two solutions I found (1) differential transmitters and receivers at > each end, like RS-422 type work, or (2) simply move the thunderbolt > physicaly close and use an 18 inch cable. > > Take my word for it, the T-Bolt is not able to drive a 100 foot long > twisted pair cable > > > > > > Not so for the 10MHz though > > > > Didier KO4BB > > > > Sent from my BlackBerry Wireless thingy while I do other things... > > > > -----Original Message----- > > From: "David C. Partridge" <[email protected]> > > Sender: [email protected] > > Date: Thu, 14 Jun 2012 01:59:42 > > To: 'Chris Wilson'<[email protected]>; 'Discussion of precise time > and frequency measurement'<[email protected]> > > Reply-To: Discussion of precise time and frequency measurement > > <[email protected]> > > Subject: Re: [time-nuts] Another ThunderBolt cabling question > > > > No you can't load the 10MHz (or the PPS) with five instruments in > parallel. You need a distribution amplifier. > > > > Dave > > -----Original Message----- > > From: [email protected] [mailto:[email protected]] On > Behalf Of Chris Wilson > > Sent: 13 June 2012 22:33 > > To: Discussion of precise time and frequency measurement > > Subject: [time-nuts] Another ThunderBolt cabling question > > > > > > > > 13/06/2012 22:27 > > > > About to do the permanent installation, if I bring two leads from the 10 > MHz and 1 PPS BNC sockets on the TB to a panel in my shck can i have say 5 > BNC sockets on the panel wired in parallel, with the lead from the 10 MHz > socket on the TB feeding them all? And a single socket for the 1 PPS? Any > need to screen the back of the socket panel, or enclose it in a metal box? > Cheers. > > > > Oh, I have been running lady Heather for a while tonight, here's a > screen capture, does it look OK, ther's suddenly just two traces appeared? > Thanks. http://www.chriswilson.tv/heather.png > > > > -- > > Best Regards, > > Chris Wilson. > > mailto: [email protected] > > > > > > _______________________________________________ > > 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. > > > > -- > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > 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.
