[time-nuts] Connor Winfield FTS125-CTV or FTS125-COO
Hello, Has anyone got one of the Connor Winfield FTS125-COO or FTS125-CTV GPS modules they want to sell. In 100% working order. I'm looking to replace a faulty one that's used in one of my old products. Best Regards Martyn ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Query about List and about 10 MHz Distro
Hey: Don't forget that the cable itself is noisy when moved. Especially Teflon insulation. Don On 2021-08-30 06:51, Bob kb8tq wrote: Hi This sort of trouble with BNC’s has been going on a lot longer than they have been coming in from China. A lot of folks use them *way* past the point they should. They do indeed wear out. They also come loose on the cable. We went a bit nuts “killing off” all the BNC cables in the area back in …errr … 1976. The result was a significant bump in the supples budget that month and the elimination of a whole bunch of problems on a number of tests. Back in that era Motorola could afford to buy / fab a few cables. Did the saved labor hours justify the expense? We claimed it did……It most certainly made life easier. Bob On Aug 30, 2021, at 1:26 AM, Darren Freeman wrote: On Sun, 2021-08-29 at 09:21 -0500, Dana Whitlow wrote: I believe that a significant problem in my case was not leakage through the shield, but rather common-mode currents on the cable. My experiences were with RG-6 style cable, Chiming in with a maybe tangential issue. I had some really unreliable strange behaviour in my lab, and I traced it to some low quality BNC crimp plugs. The noise at my receiver would fluctuate by tens of dB, as I wiggled the connector. With a good connector, it's dead quiet all of the time. My conclusion was that the outer conductor was not making contact when the plug was mated with a socket, and so outer currents were flowing through the spring, and through the part of the plug that you rotate when locking it to the socket. That adds some impedance, and your receiver is now also listening to the common-mode current, that should flow harmlessly to the chassis. Visually, you can spot these particular bad plugs from the lack of slots in the outer conductor. There's no way for it to compress as it's mated with the socket, so they are under-sized instead. They often feel loose. It may work sometimes, but not with all sockets, and only if gravity is pulling on the cable just right. All of the ones I've received from China have been like this. They went in the bin. The ones from Jaycar, my local electronics shop, appear to be identical. I used them anyway, because I was travelling a lot. Since that time, I have been cutting them off my cables, hopefully I've gotten them all. It's been a sad lesson. Time and money down the drain, but at least I worked out what was going on in the end. Maybe someone else is struggling with this issue? Try wiggling all the connectors :) Have fun, Darren ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. The whole world is a straight man. -- Dr. Don Latham AJ7LL PO Box 404, Frenchtown, MT, 59834 VOX: 406-626-4304 ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Query about List and about 10 MHz Distro
On 8/29/21 11:07 PM, Anders Wallin wrote: FWIW we've played with various SMA-to-SFP converter boards in the lab for 10MHz or 100MHz distribution. A bare-bones SFP board is e.g. https://github.com/aewallin/SFP-Breakout-Board That interfaces directly to the differential AC-coupled TX and RX pins of an SFP. If you want some buffering (and limited bandwidth at the same time) you can put an op-amp as a buffer and a transformer to convert to/from the differential TX/RX. Here's a design I've used https://github.com/aewallin/SFP2SMA_2018.03 We also made a box around that board: http://www.anderswallin.net/2020/12/sfp-board-in-a-box/ If your requirements are somewhere in 1e-14 or worse then this type of passive frequency distribution should work fine for maybe a few km fiber runs. Anders This is really cool.. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Query about List and about 10 MHz Distro
Hi This sort of trouble with BNC’s has been going on a lot longer than they have been coming in from China. A lot of folks use them *way* past the point they should. They do indeed wear out. They also come loose on the cable. We went a bit nuts “killing off” all the BNC cables in the area back in …errr … 1976. The result was a significant bump in the supples budget that month and the elimination of a whole bunch of problems on a number of tests. Back in that era Motorola could afford to buy / fab a few cables. Did the saved labor hours justify the expense? We claimed it did……It most certainly made life easier. Bob > On Aug 30, 2021, at 1:26 AM, Darren Freeman > wrote: > > On Sun, 2021-08-29 at 09:21 -0500, Dana Whitlow wrote: >> I believe that a significant problem in my case was not leakage >> through the >> shield, but >> rather common-mode currents on the cable. My experiences were with >> RG-6 >> style cable, > > Chiming in with a maybe tangential issue. > > I had some really unreliable strange behaviour in my lab, and I traced > it to some low quality BNC crimp plugs. The noise at my receiver would > fluctuate by tens of dB, as I wiggled the connector. With a good > connector, it's dead quiet all of the time. > > My conclusion was that the outer conductor was not making contact when > the plug was mated with a socket, and so outer currents were flowing > through the spring, and through the part of the plug that you rotate > when locking it to the socket. That adds some impedance, and your > receiver is now also listening to the common-mode current, that should > flow harmlessly to the chassis. > > Visually, you can spot these particular bad plugs from the lack of > slots in the outer conductor. There's no way for it to compress as it's > mated with the socket, so they are under-sized instead. They often feel > loose. It may work sometimes, but not with all sockets, and only if > gravity is pulling on the cable just right. > > All of the ones I've received from China have been like this. They went > in the bin. The ones from Jaycar, my local electronics shop, appear to > be identical. I used them anyway, because I was travelling a lot. Since > that time, I have been cutting them off my cables, hopefully I've > gotten them all. > > It's been a sad lesson. Time and money down the drain, but at least I > worked out what was going on in the end. > > Maybe someone else is struggling with this issue? Try wiggling all the > connectors :) > > Have fun, > Darren > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Query about List and about 10 MHz Distro
On Sun, 2021-08-29 at 09:21 -0500, Dana Whitlow wrote: > I believe that a significant problem in my case was not leakage > through the > shield, but > rather common-mode currents on the cable. My experiences were with > RG-6 > style cable, Chiming in with a maybe tangential issue. I had some really unreliable strange behaviour in my lab, and I traced it to some low quality BNC crimp plugs. The noise at my receiver would fluctuate by tens of dB, as I wiggled the connector. With a good connector, it's dead quiet all of the time. My conclusion was that the outer conductor was not making contact when the plug was mated with a socket, and so outer currents were flowing through the spring, and through the part of the plug that you rotate when locking it to the socket. That adds some impedance, and your receiver is now also listening to the common-mode current, that should flow harmlessly to the chassis. Visually, you can spot these particular bad plugs from the lack of slots in the outer conductor. There's no way for it to compress as it's mated with the socket, so they are under-sized instead. They often feel loose. It may work sometimes, but not with all sockets, and only if gravity is pulling on the cable just right. All of the ones I've received from China have been like this. They went in the bin. The ones from Jaycar, my local electronics shop, appear to be identical. I used them anyway, because I was travelling a lot. Since that time, I have been cutting them off my cables, hopefully I've gotten them all. It's been a sad lesson. Time and money down the drain, but at least I worked out what was going on in the end. Maybe someone else is struggling with this issue? Try wiggling all the connectors :) Have fun, Darren ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Query about List and about 10 MHz Distro
FWIW we've played with various SMA-to-SFP converter boards in the lab for 10MHz or 100MHz distribution. A bare-bones SFP board is e.g. https://github.com/aewallin/SFP-Breakout-Board That interfaces directly to the differential AC-coupled TX and RX pins of an SFP. If you want some buffering (and limited bandwidth at the same time) you can put an op-amp as a buffer and a transformer to convert to/from the differential TX/RX. Here's a design I've used https://github.com/aewallin/SFP2SMA_2018.03 We also made a box around that board: http://www.anderswallin.net/2020/12/sfp-board-in-a-box/ If your requirements are somewhere in 1e-14 or worse then this type of passive frequency distribution should work fine for maybe a few km fiber runs. Anders On Mon, Aug 30, 2021 at 8:13 AM Poul-Henning Kamp wrote: > > David I. Emery writes: > > On Sun, Aug 29, 2021 at 10:43:51AM -0400, paul swed wrote: > > > Not completely clear what the common > > mode Z of the things is at 10 MHz... > > Twisted pair is 135 Ohm. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
