[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.
[time-nuts] Re: Query about List and about 10 MHz Distro
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] Re: Query about List and about 10 MHz Distro
On Sun, Aug 29, 2021 at 10:43:51AM -0400, paul swed wrote: > We my only issue is every time we had a lightning storm it seemed to > fry the ICs. While they may not have ideal behavior with temperature (and related phase/group delay changes) the old antique 10Mbs era balanced twisted pair ethernet transformer/filter modules did eliminate common mode energy getting into the receivers (and transmitter) which it sounds like was the cause of your lightning EMP problem. For 10 MHz these ought to work pretty well with twisted pairs as they provide galvanic isolation breaking ground loops. Not completely clear what the common mode Z of the things is at 10 MHz... but unless there is a deliberate cap from a center tap to local ground I'd guess it would be significantly high given just winding to winding capacitance. I do certainly beleive that optical transmission is the better solution... however. -- Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, Mass 02493 "An empty zombie mind with a forlorn barely readable weatherbeaten 'For Rent' sign still vainly flapping outside on the weed encrusted pole - in celebration of what could have been, but wasn't and is not to be now either." ___ 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, 29 Aug 2021 13:56:42 -0400, time-nuts-requ...@lists.febo.com wrote: Re: time-nuts Digest, Vol 208, Issue 24 (messages 2, 4, and 15) > --2 Date: Sun, 29 Aug 2021 09:51:39 -0400 From: Bob kb8tq Subject: [time-nuts] Re: Query about List and about 10 MHz Distro To: Discussion of precise time and frequency measurement Hi Skin depth is what gets you with most coax at 10 MHz, even with the “double shield” stuff. Hardline with a nice heavy outer would do better. It’s not terribly practical around the typical lab. Might not be a bad choice for a “burry in the yard” setup though. With normal cable, the losses from the soil at normal burial depths make a good shield, that makes dealing with it questionable even there …. Bob >> On Aug 29, 2021, at 9:36 AM, Robert DiRosario wrote: What about double shielded RG-223, or Thinnet ethernet cable? Most Thinnet has both a braided shield and a foil wrap. Robert > --3 Date: Sun, 29 Aug 2021 09:21:32 -0500 From: Dana Whitlow Subject: [time-nuts] Re: Query about List and about 10 MHz Distro To: Discussion of precise time and frequency measurement 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, namely a cable that mostly went around the outside of the house for TV distribution. I get all the TV I want with an indoor dipole, and I had had plans of using that TV cable for ham purposes. One thing I have noted is that adding ferrite common mode chokes near the ends of the cable did help quite a bit, just not enough. > --15 Date: Sun, 29 Aug 2021 13:29:26 -0400 From: Robert DiRosario Subject: [time-nuts] Re: Query about List and about 10 MHz Distro To: time-nuts@lists.febo.com Andrew Sureflex (FSJ) is a lot more flexible then the LDF4 Healix, which is what you find a lot of on ebay and at hamfests. Here is some 1/4" Sureflex, new: Andrew Type N Male to Type N Male Sureflex Cable 30 feet F1RNA-PNMNM-30-L1 NEW! https://www.ebay.com/itm/173863049072 US $30.00 + $13.02 Shipping. For two pieces shipping goes to $16.33, for three $22.90 You can cut it with a hacksaw, do NOT use wire cutters. Connectors can be installed with just hand tools. If you move the test equipment around it's not very practical, but if it's setup on a bench or in a rack it will work. Robert Those large 10 MHz distribution systems typically used Heliax cable, which as a solid copper foil shield, with better than 100 dB/meter shielding effectiveness (SE). Actually, I think that's the limit of their ability to measure SE. Back when we did underground nuclear tests, the cable connecting down-hole instruments to instruments a safe distance away were Heliax. At power-line frequencies, the skin depth well exceeds the thickness of any reasonable shield, so the transfer impedance (between inside skin and outside skins) is the DC resistance of the shield. Power-frequency ground loops can be a problem, and common-mode chokes are not effective against this, but 10 MHz RF transformers intended for galvanic isolation are. May also need a blocking capacitor to prevent transformer core saturation. As for common-mode chokes, one can implement such things by winding insulated coaxial cable multiple times through a big ferrite toroid core. The insulation jacket prevents the cable shields from shorting to one another. This dodge also works for shielded twisted pair cable. This dodge is discussed in the books on Balun Transformers, and is raised to a high art in the book on Coaxial AC Bridges. Joe Gwinn ___ 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 10:29 AM, Robert DiRosario wrote: Andrew Sureflex (FSJ) is a lot more flexible then the LDF4 Healix, which is what you find a lot of on ebay and at hamfests. Here is some 1/4" Sureflex, new: Andrew Type N Male to Type N Male Sureflex Cable 30 feet F1RNA-PNMNM-30-L1 NEW! https://www.ebay.com/itm/173863049072 US $30.00 + $13.02 Shipping. For two pieces shipping goes to $16.33, for three $22.90 You can cut it with a hacksaw, do NOT use wire cutters. Connectors can be installed with just hand tools. If you move the test equipment around it's not very practical, but if it's setup on a bench or in a rack it will work. Robert ya know.. system cost for optical fiber is probably cheaper than hardline - the cable certainly is (about $15 for a 100 ft duplex single mode). And the analog/optical converters at either end are probably cheaper than hardline coax connectors. And *way* easier to install. We just need to figure out which COTS media converter is right for "time-nuts" usage. ___ 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
This has been an interesting thread. I purchased some 1/4" FSJ with BNC connectors from the usual auction site years ago for time nuts use but never installed it. It does seem to be a bit of a hassle to use in my time lab (I do use some FSJ with N connectors in parts of my home amateur radio station.) I suspect I haven't looked hard enough for troubling leakage at 10 MHz from the RG400 I mostly use. I have the FSJ to fall back on if I take my time nuts hobby to the next level. Some of the fiber ideas seem promising as well. Mark Spencer m...@alignedsolutions.com 604 762 4099 > On Aug 29, 2021, at 10:29 AM, Robert DiRosario wrote: > > Andrew Sureflex (FSJ) is a lot more flexible then the LDF4 Healix, which is > what you find a > lot of on ebay and at hamfests. > > Here is some 1/4" Sureflex, new: > > Andrew Type N Male to Type N Male Sureflex Cable 30 feet F1RNA-PNMNM-30-L1 > NEW! > https://www.ebay.com/itm/173863049072 > US $30.00 + $13.02 Shipping. For two pieces shipping goes to $16.33, for > three $22.90 > > You can cut it with a hacksaw, do NOT use wire cutters. Connectors can be > installed with just hand tools. > > If you move the test equipment around it's not very practical, but if it's > setup on > a bench or in a rack it will work. > > Robert > > > >> On 08/29/2021 09:51 AM, Bob kb8tq wrote: >> Hi >> >> Skin depth is what gets you with most coax at 10 MHz, even with the “double >> shield” stuff. Hardline with a nice heavy outer would do better. It’s not >> terribly >> practical around the typical lab. Might not be a bad choice for a “burry in >> the yard” >> setup though. With normal cable, the losses from the soil at normal burial >> depths make a good shield, that makes dealing with it questionable even >> there …. >> >> Bob >> >>> On Aug 29, 2021, at 9:36 AM, Robert DiRosario wrote: >>> >>> What about double shielded RG-223, or Thinnet ethernet cable? >>> Most Thinnet has both a braided shield and a foil wrap. >>> >>> Robert >>> On 08/28/2021 08:26 PM, Bob kb8tq wrote: Hi Anything you do that has a bunch of 10 MHz cables running out from here or there will impact your ability to listen to WWV at 10 MHz :) Other than killing all the sources, there is no silver bullet. Bob > On Aug 28, 2021, at 7:57 PM, Dana Whitlow wrote: > > Bob, my own motivation for going to fiber was entirely different. I > simply wanted to > run 10 MHz all over the place from reference sources in disparate > locations in the > house, and I quickly discovered that cable leakage was embarrassingly > severe. So > I shut down and began contemplating a fiber link. But then reality set in > and I realized > that running fiber across the house had its own big problems, so I set the > project aside. > > Dana > > > On Sat, Aug 28, 2021 at 3:3 ___ 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 With *any* cable setup, proper termination is vital. An improperly terminated balanced line can be just as bad as a poorly terminated coax. Things like common mode chokes are part of a *lot* of setups. What gets messy is that a lot of gear does not properly terminate the cable. It’s high-z so you can run a bunch of them with Tee connectors or some other strange approach. >20 db of return loss is *not* what most cables get terminated in. It doesn’t take a lot of coax to get a quarter wave at 10 MHz. Anything nearly that long is going to be a radiator if you let it. This all gets a bit insane if you have multiple 10 MHz sources (like devices you are testing). Close in phase noise and ADEV both can get really strange as a result. Lots of issues …. Bob > On Aug 29, 2021, at 10:44 AM, Dana Whitlow wrote: > > Andy, > > Balanced twisted pair may be helpful, but only if adequate precautions are > taken to > avoid creation of common mode *currents *on the line*.* > > Dana > > > On Sun, Aug 29, 2021 at 9:34 AM Andy Talbot wrote: > >> Hence my observation that balanced twisted pair might be a better solution >> than coax for 10MHz distribution >> Removes all possibility of ground loops >> >> Andy >> www.g4jnt.com >> >> >> >> On Sun, 29 Aug 2021 at 15:22, 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, >>> namely a cable that mostly went around the outside of the house for TV >>> distribution. >> ___ >> 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 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
Andrew Sureflex (FSJ) is a lot more flexible then the LDF4 Healix, which
is what you find a
lot of on ebay and at hamfests.
Here is some 1/4" Sureflex, new:
Andrew Type N Male to Type N Male Sureflex Cable 30 feet
F1RNA-PNMNM-30-L1 NEW!
https://www.ebay.com/itm/173863049072
US $30.00 + $13.02 Shipping. For two pieces shipping goes to $16.33,
for three $22.90
You can cut it with a hacksaw, do NOT use wire cutters. Connectors can be
installed with just hand tools.
If you move the test equipment around it's not very practical, but if
it's setup on
a bench or in a rack it will work.
Robert
On 08/29/2021 09:51 AM, Bob kb8tq wrote:
Hi
Skin depth is what gets you with most coax at 10 MHz, even with the “double
shield” stuff. Hardline with a nice heavy outer would do better. It’s not
terribly
practical around the typical lab. Might not be a bad choice for a “burry in the
yard”
setup though. With normal cable, the losses from the soil at normal burial
depths make a good shield, that makes dealing with it questionable even there ….
Bob
On Aug 29, 2021, at 9:36 AM, Robert DiRosario wrote:
What about double shielded RG-223, or Thinnet ethernet cable?
Most Thinnet has both a braided shield and a foil wrap.
Robert
On 08/28/2021 08:26 PM, Bob kb8tq wrote:
Hi
Anything you do that has a bunch of 10 MHz cables running out from here or there
will impact your ability to listen to WWV at 10 MHz :) Other than killing all
the sources,
there is no silver bullet.
Bob
On Aug 28, 2021, at 7:57 PM, Dana Whitlow wrote:
Bob, my own motivation for going to fiber was entirely different. I
simply wanted to
run 10 MHz all over the place from reference sources in disparate
locations in the
house, and I quickly discovered that cable leakage was embarrassingly
severe. So
I shut down and began contemplating a fiber link. But then reality set in
and I realized
that running fiber across the house had its own big problems, so I set the
project aside.
Dana
On Sat, Aug 28, 2021 at 3:32 PM Bob kb8tq wrote:
Hi
With a whole variety of pretty good OCXO’s going for cheap money
on eBay, it’s likely less expensive to do cleanup oscillators on the link
compared to going crazy with low noise optical this or that. Yes, you
will be getting something in the high 150’s for noise, but still pretty
good
for $10.
If you need better, spend $50 or so on a 10811. Still less money than
some of the crazy fiber stuff.
With either one, send over a high enough frequency that the loop isn’t
dealing with reference spurs in any significant way. Given the clock rates
Ethernet runs at these days, that part should be fairly straightforward.
This *assumes* that there is a crossover somewhere practical between
the fiber noise and the noise on the optical gear. You should be able to
work out what it is with some fairly normal phase noise or ADEV testing.
Bob
On Aug 28, 2021, at 3:03 PM, Dana Whitlow wrote:
I was looking for something similar about 18 months or so ago. Although
I
haven't taken any
action yet, I concluded that one could do a nice job for under $200 per
segment, including the
transmitter and receiver modules and lots of connectorized multimode
fiber. What I *don't* know
is what the phase noise performance would be, except that I do know that
the fiber's VF *is*
materially influenced by temperature.
I was looking primarily at the HFBR-2416 for the fiber receiver, and the
HFBR-1412 (standard
power) or the HFBR-1414 (high power option) for the transmitter Unlike
most of the available
models, these are fundamentally analog devices, meaning that you can
transmit sinewave
10 MHz through them. At the time I was looking, Mouser was selling these
for about $20 each.
See the datasheet at
https://www.mouser.com/datasheet/2/678/AV02-0176EN_2019-02-15-1827546.pdf
with particular attention to page 21 regarding the HFBR-2416 receiver.
I was also looking at Fiber Instrument Sales for patch cords. We bought
a
lot of fiber stuff from
them at Arecibo, and I was always happy with them. See:
https://www.fiberinstrumentsales.com/catalog-cable-assemblies?gclid=Cj0KCQjwvaeJBhCvARIsABgTDM7eNTkP2nQbyFzhcwDE38VnSEP879MBKV1ZyDq2YrnEtOn7_VfzjbkaAtpfEALw_wcB
Somebody had pointed out yet another source of connectorized fibers
("patch
cords") to me, but I cannot find the name
at the moment.
Dana K8YUM
On Sat, Aug 28, 2021 at 11:52 AM AC0XU (Jim)
wrote:
I am hoping that you can help me about a couple of things:
1) My time-nuts summaries sometimes appear unformatted and unreadable.
All
the text from all the postings is crammed together without spacing. How
can
I fix it?
2) I want to distribute 10 MHz references by fiber. There are
RF-over-Fiber products available, but too expensive for me (thousands of
$$$ per xmit/rcv set). I am thinking that it should be possible to use
fiber Ethernet components to do this. I don't mean IEEE 1588 but a much
simpler, no-computer-required, solution. Possibly just converting
[time-nuts] Re: Query about List and about 10 MHz Distro
On Sun, 29 Aug 2021 03:30:23 -0400, time-nuts-requ...@lists.febo.com wrote: Re: time-nuts Digest, Vol 208, Issue 23 (message 3) > Date: Sat, 28 Aug 2021 18:57:08 -0500 > From: Dana Whitlow > Subject: [time-nuts] Re: Query about List and about 10 MHz Distro > To: Discussion of precise time and frequency measurement > > > Bob, my own motivation for going to fiber was entirely different. I > simply wanted to > run 10 MHz all over the place from reference sources in disparate > locations in the > house, and I quickly discovered that cable leakage was embarrassingly > severe. So > I shut down and began contemplating a fiber link. But then reality set in > and I realized > that running fiber across the house had its own big problems, so I set the > project aside. > > Dana I've run a lot of 10 MHz distribution coaxial cable, in a tree with links as long as 50 meters, and planned systems where the links were a few hundred meters. It's necessary to use double-shielded coax with machined TNC (not BNC) connectors on cables and the (passive) power dividers. The cable shielding effectiveness must exceed 80 dB per meter. Be sure to torque the connectors to the "inspection torque" range specified by the connector manufacturer. At 10 MHz, cable losses are minimal. .<https://patents.google.com/patent/US9261587B1> Joe Gwinn ___ 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
Robert wrote: What about double shielded RG-223, or Thinnet ethernet cable? Most Thinnet has both a braided shield and a foil wrap. IME, thinnet cable is notoriously leaky. I have also not had success with double-shielded cables such as RG-223. Unless you go all the way to hardline (some of which can be bent to some degree for installation), there is not much you can do with shielded coax. No amount of braided and/or foil shielding will really do the job effectively. A braid-and-foil shield (or double-braid + foil) over a twisted pair is better, but in practice (for our purposes) not usually enough (again, IME). Properly specified and installed *triaxial* cables can get you there, but understand that you would need to change the connectors on your instruments to gain the full benefit. Also understand that proper installation of triax cables and connectors is not trivial. Best regards, Charles ___ 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
exactly On Sun, Aug 29, 2021 at 10:45 AM Dana Whitlow wrote: > Andy, > > Balanced twisted pair may be helpful, but only if adequate precautions are > taken to > avoid creation of common mode *currents *on the line*.* > > Dana > > > On Sun, Aug 29, 2021 at 9:34 AM Andy Talbot wrote: > > > Hence my observation that balanced twisted pair might be a better > solution > > than coax for 10MHz distribution > > Removes all possibility of ground loops > > > > Andy > > www.g4jnt.com > > > > > > > > On Sun, 29 Aug 2021 at 15:22, 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, > > > namely a cable that mostly went around the outside of the house for TV > > > distribution. > > ___ > > 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 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
Andy, Balanced twisted pair may be helpful, but only if adequate precautions are taken to avoid creation of common mode *currents *on the line*.* Dana On Sun, Aug 29, 2021 at 9:34 AM Andy Talbot wrote: > Hence my observation that balanced twisted pair might be a better solution > than coax for 10MHz distribution > Removes all possibility of ground loops > > Andy > www.g4jnt.com > > > > On Sun, 29 Aug 2021 at 15:22, 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, > > namely a cable that mostly went around the outside of the house for TV > > distribution. > ___ > 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
Andy The balanced line does work and does reduce the emissions on a 160 ft run. Used it for 1, 5, 10 MHz. We my only issue is every time we had a lightning storm it seemed to fry the ICs. The line drivers and receivers were analog devices ADSL type technology. Was a bit of a pain to deal with as they were smt devices. Tried various suppression methods. I am sure there was a way. But I went back to coax. I have also considered optics. HP had written a paper on using them circa 1990 approx. for frequency distribution. Regards Paul WB8TSL On Sun, Aug 29, 2021 at 10:34 AM Andy Talbot wrote: > Hence my observation that balanced twisted pair might be a better solution > than coax for 10MHz distribution > Removes all possibility of ground loops > > Andy > www.g4jnt.com > > > > On Sun, 29 Aug 2021 at 15:22, 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, > > namely a cable that mostly went around the outside of the house for TV > > distribution. > ___ > 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
Hence my observation that balanced twisted pair might be a better solution than coax for 10MHz distribution Removes all possibility of ground loops Andy www.g4jnt.com On Sun, 29 Aug 2021 at 15:22, 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, > namely a cable that mostly went around the outside of the house for TV > distribution. ___ 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
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, namely a cable that mostly went around the outside of the house for TV distribution. I get all the TV I want with an indoor dipole, and I had had plans of using that TV cable for ham purposes. One thing I have noted is that adding ferrite common mode chokes near the ends of the cable did help quite a bit, just not enough. Those who are conversant with RF shielding concepts will recognize that this puts most of the blame squarely on my own shoulders, for not putting my kluges in proper enclosures. But I'm retired, old, shaky, tired, etc, and am not too ambitious any more. But I take some solace in the observation that I'm not the only one; much of the commercially-built equipment I own has similar (and quite obvious) flaws. I worked in the Tektronix spectrum analyzer group some years back, and one of my side tasks was taking instruments over to the EMI lab for compliance tests. On more than one occasion those people told me that they were always delighted to test stuff designed by our group, because it was designed and built well enough that it almost always passed FCC specs on the first round. Dana On Sun, Aug 29, 2021 at 8:52 AM Bob kb8tq wrote: > Hi > > Skin depth is what gets you with most coax at 10 MHz, even with the > “double > shield” stuff. Hardline with a nice heavy outer would do better. It’s not > terribly > practical around the typical lab. Might not be a bad choice for a “burry > in the yard” > setup though. With normal cable, the losses from the soil at normal burial > depths make a good shield, that makes dealing with it questionable even > there …. > > Bob > > > On Aug 29, 2021, at 9:36 AM, Robert DiRosario > wrote: > > > > What about double shielded RG-223, or Thinnet ethernet cable? > > Most Thinnet has both a braided shield and a foil wrap. > > > > Robert > > > > On 08/28/2021 08:26 PM, Bob kb8tq wrote: > >> Hi > >> > >> Anything you do that has a bunch of 10 MHz cables running out from here > or there > >> will impact your ability to listen to WWV at 10 MHz :) Other than > killing all the sources, > >> there is no silver bullet. > >> > >> Bob > >> > >>> On Aug 28, 2021, at 7:57 PM, Dana Whitlow > wrote: > >>> > >>> Bob, my own motivation for going to fiber was entirely different. I > >>> simply wanted to > >>> run 10 MHz all over the place from reference sources in disparate > >>> locations in the > >>> house, and I quickly discovered that cable leakage was embarrassingly > >>> severe. So > >>> I shut down and began contemplating a fiber link. But then reality > set in > >>> and I realized > >>> that running fiber across the house had its own big problems, so I set > the > >>> project aside. > >>> > >>> Dana > >>> > >>> > >>> On Sat, Aug 28, 2021 at 3:32 PM Bob kb8tq wrote: > >>> > Hi > > With a whole variety of pretty good OCXO’s going for cheap money > on eBay, it’s likely less expensive to do cleanup oscillators on the > link > compared to going crazy with low noise optical this or that. Yes, you > will be getting something in the high 150’s for noise, but still > pretty > good > for $10. > > If you need better, spend $50 or so on a 10811. Still less money than > some of the crazy fiber stuff. > > With either one, send over a high enough frequency that the loop isn’t > dealing with reference spurs in any significant way. Given the clock > rates > Ethernet runs at these days, that part should be fairly > straightforward. > > This *assumes* that there is a crossover somewhere practical between > the fiber noise and the noise on the optical gear. You should be able > to > work out what it is with some fairly normal phase noise or ADEV > testing. > > Bob > > > On Aug 28, 2021, at 3:03 PM, Dana Whitlow > wrote: > > > > I was looking for something similar about 18 months or so ago. > Although > I > > haven't taken any > > action yet, I concluded that one could do a nice job for under $200 > per > > segment, including the > > transmitter and receiver modules and lots of connectorized multimode > > fiber. What I *don't* know > > is what the phase noise performance would be, except that I do know > that > > the fiber's VF *is* > > materially influenced by temperature. > > > > I was looking primarily at the HFBR-2416 for the fiber receiver, and > the > > HFBR-1412 (standard > > power) or the HFBR-1414 (high power option) for the transmitter > Unlike > > most of the available > > models, these are fundamentally analog devices, meaning that you can > > transmit sinewave > > 10 MHz through them. At the time I was looking, Mouser was selling > these > > for about $20 each. > > > > See the datasheet at > >
[time-nuts] Re: Query about List and about 10 MHz Distro
Hi
Skin depth is what gets you with most coax at 10 MHz, even with the “double
shield” stuff. Hardline with a nice heavy outer would do better. It’s not
terribly
practical around the typical lab. Might not be a bad choice for a “burry in the
yard”
setup though. With normal cable, the losses from the soil at normal burial
depths make a good shield, that makes dealing with it questionable even there ….
Bob
> On Aug 29, 2021, at 9:36 AM, Robert DiRosario wrote:
>
> What about double shielded RG-223, or Thinnet ethernet cable?
> Most Thinnet has both a braided shield and a foil wrap.
>
> Robert
>
> On 08/28/2021 08:26 PM, Bob kb8tq wrote:
>> Hi
>>
>> Anything you do that has a bunch of 10 MHz cables running out from here or
>> there
>> will impact your ability to listen to WWV at 10 MHz :) Other than killing
>> all the sources,
>> there is no silver bullet.
>>
>> Bob
>>
>>> On Aug 28, 2021, at 7:57 PM, Dana Whitlow wrote:
>>>
>>> Bob, my own motivation for going to fiber was entirely different. I
>>> simply wanted to
>>> run 10 MHz all over the place from reference sources in disparate
>>> locations in the
>>> house, and I quickly discovered that cable leakage was embarrassingly
>>> severe. So
>>> I shut down and began contemplating a fiber link. But then reality set in
>>> and I realized
>>> that running fiber across the house had its own big problems, so I set the
>>> project aside.
>>>
>>> Dana
>>>
>>>
>>> On Sat, Aug 28, 2021 at 3:32 PM Bob kb8tq wrote:
>>>
Hi
With a whole variety of pretty good OCXO’s going for cheap money
on eBay, it’s likely less expensive to do cleanup oscillators on the link
compared to going crazy with low noise optical this or that. Yes, you
will be getting something in the high 150’s for noise, but still pretty
good
for $10.
If you need better, spend $50 or so on a 10811. Still less money than
some of the crazy fiber stuff.
With either one, send over a high enough frequency that the loop isn’t
dealing with reference spurs in any significant way. Given the clock rates
Ethernet runs at these days, that part should be fairly straightforward.
This *assumes* that there is a crossover somewhere practical between
the fiber noise and the noise on the optical gear. You should be able to
work out what it is with some fairly normal phase noise or ADEV testing.
Bob
> On Aug 28, 2021, at 3:03 PM, Dana Whitlow wrote:
>
> I was looking for something similar about 18 months or so ago. Although
I
> haven't taken any
> action yet, I concluded that one could do a nice job for under $200 per
> segment, including the
> transmitter and receiver modules and lots of connectorized multimode
> fiber. What I *don't* know
> is what the phase noise performance would be, except that I do know that
> the fiber's VF *is*
> materially influenced by temperature.
>
> I was looking primarily at the HFBR-2416 for the fiber receiver, and the
> HFBR-1412 (standard
> power) or the HFBR-1414 (high power option) for the transmitter Unlike
> most of the available
> models, these are fundamentally analog devices, meaning that you can
> transmit sinewave
> 10 MHz through them. At the time I was looking, Mouser was selling these
> for about $20 each.
>
> See the datasheet at
>
https://www.mouser.com/datasheet/2/678/AV02-0176EN_2019-02-15-1827546.pdf
> with particular attention to page 21 regarding the HFBR-2416 receiver.
>
> I was also looking at Fiber Instrument Sales for patch cords. We bought
a
> lot of fiber stuff from
> them at Arecibo, and I was always happy with them. See:
>
https://www.fiberinstrumentsales.com/catalog-cable-assemblies?gclid=Cj0KCQjwvaeJBhCvARIsABgTDM7eNTkP2nQbyFzhcwDE38VnSEP879MBKV1ZyDq2YrnEtOn7_VfzjbkaAtpfEALw_wcB
> Somebody had pointed out yet another source of connectorized fibers
("patch
> cords") to me, but I cannot find the name
> at the moment.
>
> Dana K8YUM
>
>
> On Sat, Aug 28, 2021 at 11:52 AM AC0XU (Jim)
> wrote:
>
>> I am hoping that you can help me about a couple of things:
>>
>> 1) My time-nuts summaries sometimes appear unformatted and unreadable.
All
>> the text from all the postings is crammed together without spacing. How
can
>> I fix it?
>>
>> 2) I want to distribute 10 MHz references by fiber. There are
>> RF-over-Fiber products available, but too expensive for me (thousands of
>> $$$ per xmit/rcv set). I am thinking that it should be possible to use
>> fiber Ethernet components to do this. I don't mean IEEE 1588 but a much
>> simpler, no-computer-required, solution. Possibly just converting sine
wave
>> (coax) to square wave (fiber) to sine wave (coax). I am looking for a
>>>
[time-nuts] Re: Query about List and about 10 MHz Distro
What about double shielded RG-223, or Thinnet ethernet cable?
Most Thinnet has both a braided shield and a foil wrap.
Robert
On 08/28/2021 08:26 PM, Bob kb8tq wrote:
Hi
Anything you do that has a bunch of 10 MHz cables running out from here or there
will impact your ability to listen to WWV at 10 MHz :) Other than killing all
the sources,
there is no silver bullet.
Bob
On Aug 28, 2021, at 7:57 PM, Dana Whitlow wrote:
Bob, my own motivation for going to fiber was entirely different. I
simply wanted to
run 10 MHz all over the place from reference sources in disparate
locations in the
house, and I quickly discovered that cable leakage was embarrassingly
severe. So
I shut down and began contemplating a fiber link. But then reality set in
and I realized
that running fiber across the house had its own big problems, so I set the
project aside.
Dana
On Sat, Aug 28, 2021 at 3:32 PM Bob kb8tq wrote:
Hi
With a whole variety of pretty good OCXO’s going for cheap money
on eBay, it’s likely less expensive to do cleanup oscillators on the link
compared to going crazy with low noise optical this or that. Yes, you
will be getting something in the high 150’s for noise, but still pretty
good
for $10.
If you need better, spend $50 or so on a 10811. Still less money than
some of the crazy fiber stuff.
With either one, send over a high enough frequency that the loop isn’t
dealing with reference spurs in any significant way. Given the clock rates
Ethernet runs at these days, that part should be fairly straightforward.
This *assumes* that there is a crossover somewhere practical between
the fiber noise and the noise on the optical gear. You should be able to
work out what it is with some fairly normal phase noise or ADEV testing.
Bob
On Aug 28, 2021, at 3:03 PM, Dana Whitlow wrote:
I was looking for something similar about 18 months or so ago. Although
I
haven't taken any
action yet, I concluded that one could do a nice job for under $200 per
segment, including the
transmitter and receiver modules and lots of connectorized multimode
fiber. What I *don't* know
is what the phase noise performance would be, except that I do know that
the fiber's VF *is*
materially influenced by temperature.
I was looking primarily at the HFBR-2416 for the fiber receiver, and the
HFBR-1412 (standard
power) or the HFBR-1414 (high power option) for the transmitter Unlike
most of the available
models, these are fundamentally analog devices, meaning that you can
transmit sinewave
10 MHz through them. At the time I was looking, Mouser was selling these
for about $20 each.
See the datasheet at
https://www.mouser.com/datasheet/2/678/AV02-0176EN_2019-02-15-1827546.pdf
with particular attention to page 21 regarding the HFBR-2416 receiver.
I was also looking at Fiber Instrument Sales for patch cords. We bought
a
lot of fiber stuff from
them at Arecibo, and I was always happy with them. See:
https://www.fiberinstrumentsales.com/catalog-cable-assemblies?gclid=Cj0KCQjwvaeJBhCvARIsABgTDM7eNTkP2nQbyFzhcwDE38VnSEP879MBKV1ZyDq2YrnEtOn7_VfzjbkaAtpfEALw_wcB
Somebody had pointed out yet another source of connectorized fibers
("patch
cords") to me, but I cannot find the name
at the moment.
Dana K8YUM
On Sat, Aug 28, 2021 at 11:52 AM AC0XU (Jim)
wrote:
I am hoping that you can help me about a couple of things:
1) My time-nuts summaries sometimes appear unformatted and unreadable.
All
the text from all the postings is crammed together without spacing. How
can
I fix it?
2) I want to distribute 10 MHz references by fiber. There are
RF-over-Fiber products available, but too expensive for me (thousands of
$$$ per xmit/rcv set). I am thinking that it should be possible to use
fiber Ethernet components to do this. I don't mean IEEE 1588 but a much
simpler, no-computer-required, solution. Possibly just converting sine
wave
(coax) to square wave (fiber) to sine wave (coax). I am looking for a
low
cost solution. Any thoughts or recommendations??
Thanks!
Jim
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[time-nuts] Re: Query about List and about 10 MHz Distro
Bob,
In my case simply disconnecting the long interconnecting cables at both
ends almost
completely eliminated the problem. Hence my expectation that use of fiber
optics
would be effective.
Dana
On Sat, Aug 28, 2021 at 7:27 PM Bob kb8tq wrote:
> Hi
>
> Anything you do that has a bunch of 10 MHz cables running out from here or
> there
> will impact your ability to listen to WWV at 10 MHz :) Other than killing
> all the sources,
> there is no silver bullet.
>
> Bob
>
> > On Aug 28, 2021, at 7:57 PM, Dana Whitlow wrote:
> >
> > Bob, my own motivation for going to fiber was entirely different. I
> > simply wanted to
> > run 10 MHz all over the place from reference sources in disparate
> > locations in the
> > house, and I quickly discovered that cable leakage was embarrassingly
> > severe. So
> > I shut down and began contemplating a fiber link. But then reality set
> in
> > and I realized
> > that running fiber across the house had its own big problems, so I set
> the
> > project aside.
> >
> > Dana
> >
> >
> > On Sat, Aug 28, 2021 at 3:32 PM Bob kb8tq wrote:
> >
> >> Hi
> >>
> >> With a whole variety of pretty good OCXO’s going for cheap money
> >> on eBay, it’s likely less expensive to do cleanup oscillators on the
> link
> >> compared to going crazy with low noise optical this or that. Yes, you
> >> will be getting something in the high 150’s for noise, but still pretty
> >> good
> >> for $10.
> >>
> >> If you need better, spend $50 or so on a 10811. Still less money than
> >> some of the crazy fiber stuff.
> >>
> >> With either one, send over a high enough frequency that the loop isn’t
> >> dealing with reference spurs in any significant way. Given the clock
> rates
> >> Ethernet runs at these days, that part should be fairly straightforward.
> >>
> >> This *assumes* that there is a crossover somewhere practical between
> >> the fiber noise and the noise on the optical gear. You should be able to
> >> work out what it is with some fairly normal phase noise or ADEV testing.
> >>
> >> Bob
> >>
> >>> On Aug 28, 2021, at 3:03 PM, Dana Whitlow
> wrote:
> >>>
> >>> I was looking for something similar about 18 months or so ago.
> Although
> >> I
> >>> haven't taken any
> >>> action yet, I concluded that one could do a nice job for under $200 per
> >>> segment, including the
> >>> transmitter and receiver modules and lots of connectorized multimode
> >>> fiber. What I *don't* know
> >>> is what the phase noise performance would be, except that I do know
> that
> >>> the fiber's VF *is*
> >>> materially influenced by temperature.
> >>>
> >>> I was looking primarily at the HFBR-2416 for the fiber receiver, and
> the
> >>> HFBR-1412 (standard
> >>> power) or the HFBR-1414 (high power option) for the transmitter
> Unlike
> >>> most of the available
> >>> models, these are fundamentally analog devices, meaning that you can
> >>> transmit sinewave
> >>> 10 MHz through them. At the time I was looking, Mouser was selling
> these
> >>> for about $20 each.
> >>>
> >>> See the datasheet at
> >>>
> >>
> https://www.mouser.com/datasheet/2/678/AV02-0176EN_2019-02-15-1827546.pdf
> >>> with particular attention to page 21 regarding the HFBR-2416 receiver.
> >>>
> >>> I was also looking at Fiber Instrument Sales for patch cords. We
> bought
> >> a
> >>> lot of fiber stuff from
> >>> them at Arecibo, and I was always happy with them. See:
> >>>
> >>
> https://www.fiberinstrumentsales.com/catalog-cable-assemblies?gclid=Cj0KCQjwvaeJBhCvARIsABgTDM7eNTkP2nQbyFzhcwDE38VnSEP879MBKV1ZyDq2YrnEtOn7_VfzjbkaAtpfEALw_wcB
> >>>
> >>> Somebody had pointed out yet another source of connectorized fibers
> >> ("patch
> >>> cords") to me, but I cannot find the name
> >>> at the moment.
> >>>
> >>> Dana K8YUM
> >>>
> >>>
> >>> On Sat, Aug 28, 2021 at 11:52 AM AC0XU (Jim) <
> james.schatz...@ac0xu.com>
> >>> wrote:
> >>>
> I am hoping that you can help me about a couple of things:
>
> 1) My time-nuts summaries sometimes appear unformatted and unreadable.
> >> All
> the text from all the postings is crammed together without spacing.
> How
> >> can
> I fix it?
>
> 2) I want to distribute 10 MHz references by fiber. There are
> RF-over-Fiber products available, but too expensive for me (thousands
> of
> $$$ per xmit/rcv set). I am thinking that it should be possible to
> use
> fiber Ethernet components to do this. I don't mean IEEE 1588 but a
> much
> simpler, no-computer-required, solution. Possibly just converting sine
> >> wave
> (coax) to square wave (fiber) to sine wave (coax). I am looking for a
> >> low
> cost solution. Any thoughts or recommendations??
>
> Thanks!
>
> Jim
> ___
> 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 8/28/21 4:57 PM, Dana Whitlow wrote: Bob, my own motivation for going to fiber was entirely different. I simply wanted to run 10 MHz all over the place from reference sources in disparate locations in the house, and I quickly discovered that cable leakage was embarrassingly severe. So I shut down and began contemplating a fiber link. But then reality set in and I realized that running fiber across the house had its own big problems, so I set the project aside. Dana just thinking out loud here.. there's a bucket load of cheap "media converters" around from fiber to twisted pair ethernet or RS422 - including older 10 and 100 base T. I wonder if they'd be repurposeable for 10 MHz distribution. or video over fiber widgets - used a lot for cameras and such. There's been some discussion on the list about using video distribution amps for 10MHz. ___ 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
Anything you do that has a bunch of 10 MHz cables running out from here or there
will impact your ability to listen to WWV at 10 MHz :) Other than killing all
the sources,
there is no silver bullet.
Bob
> On Aug 28, 2021, at 7:57 PM, Dana Whitlow wrote:
>
> Bob, my own motivation for going to fiber was entirely different. I
> simply wanted to
> run 10 MHz all over the place from reference sources in disparate
> locations in the
> house, and I quickly discovered that cable leakage was embarrassingly
> severe. So
> I shut down and began contemplating a fiber link. But then reality set in
> and I realized
> that running fiber across the house had its own big problems, so I set the
> project aside.
>
> Dana
>
>
> On Sat, Aug 28, 2021 at 3:32 PM Bob kb8tq wrote:
>
>> Hi
>>
>> With a whole variety of pretty good OCXO’s going for cheap money
>> on eBay, it’s likely less expensive to do cleanup oscillators on the link
>> compared to going crazy with low noise optical this or that. Yes, you
>> will be getting something in the high 150’s for noise, but still pretty
>> good
>> for $10.
>>
>> If you need better, spend $50 or so on a 10811. Still less money than
>> some of the crazy fiber stuff.
>>
>> With either one, send over a high enough frequency that the loop isn’t
>> dealing with reference spurs in any significant way. Given the clock rates
>> Ethernet runs at these days, that part should be fairly straightforward.
>>
>> This *assumes* that there is a crossover somewhere practical between
>> the fiber noise and the noise on the optical gear. You should be able to
>> work out what it is with some fairly normal phase noise or ADEV testing.
>>
>> Bob
>>
>>> On Aug 28, 2021, at 3:03 PM, Dana Whitlow wrote:
>>>
>>> I was looking for something similar about 18 months or so ago. Although
>> I
>>> haven't taken any
>>> action yet, I concluded that one could do a nice job for under $200 per
>>> segment, including the
>>> transmitter and receiver modules and lots of connectorized multimode
>>> fiber. What I *don't* know
>>> is what the phase noise performance would be, except that I do know that
>>> the fiber's VF *is*
>>> materially influenced by temperature.
>>>
>>> I was looking primarily at the HFBR-2416 for the fiber receiver, and the
>>> HFBR-1412 (standard
>>> power) or the HFBR-1414 (high power option) for the transmitter Unlike
>>> most of the available
>>> models, these are fundamentally analog devices, meaning that you can
>>> transmit sinewave
>>> 10 MHz through them. At the time I was looking, Mouser was selling these
>>> for about $20 each.
>>>
>>> See the datasheet at
>>>
>> https://www.mouser.com/datasheet/2/678/AV02-0176EN_2019-02-15-1827546.pdf
>>> with particular attention to page 21 regarding the HFBR-2416 receiver.
>>>
>>> I was also looking at Fiber Instrument Sales for patch cords. We bought
>> a
>>> lot of fiber stuff from
>>> them at Arecibo, and I was always happy with them. See:
>>>
>> https://www.fiberinstrumentsales.com/catalog-cable-assemblies?gclid=Cj0KCQjwvaeJBhCvARIsABgTDM7eNTkP2nQbyFzhcwDE38VnSEP879MBKV1ZyDq2YrnEtOn7_VfzjbkaAtpfEALw_wcB
>>>
>>> Somebody had pointed out yet another source of connectorized fibers
>> ("patch
>>> cords") to me, but I cannot find the name
>>> at the moment.
>>>
>>> Dana K8YUM
>>>
>>>
>>> On Sat, Aug 28, 2021 at 11:52 AM AC0XU (Jim)
>>> wrote:
>>>
I am hoping that you can help me about a couple of things:
1) My time-nuts summaries sometimes appear unformatted and unreadable.
>> All
the text from all the postings is crammed together without spacing. How
>> can
I fix it?
2) I want to distribute 10 MHz references by fiber. There are
RF-over-Fiber products available, but too expensive for me (thousands of
$$$ per xmit/rcv set). I am thinking that it should be possible to use
fiber Ethernet components to do this. I don't mean IEEE 1588 but a much
simpler, no-computer-required, solution. Possibly just converting sine
>> wave
(coax) to square wave (fiber) to sine wave (coax). I am looking for a
>> low
cost solution. Any thoughts or recommendations??
Thanks!
Jim
___
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 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 ma
[time-nuts] Re: Query about List and about 10 MHz Distro
Bob, my own motivation for going to fiber was entirely different. I
simply wanted to
run 10 MHz all over the place from reference sources in disparate
locations in the
house, and I quickly discovered that cable leakage was embarrassingly
severe. So
I shut down and began contemplating a fiber link. But then reality set in
and I realized
that running fiber across the house had its own big problems, so I set the
project aside.
Dana
On Sat, Aug 28, 2021 at 3:32 PM Bob kb8tq wrote:
> Hi
>
> With a whole variety of pretty good OCXO’s going for cheap money
> on eBay, it’s likely less expensive to do cleanup oscillators on the link
> compared to going crazy with low noise optical this or that. Yes, you
> will be getting something in the high 150’s for noise, but still pretty
> good
> for $10.
>
> If you need better, spend $50 or so on a 10811. Still less money than
> some of the crazy fiber stuff.
>
> With either one, send over a high enough frequency that the loop isn’t
> dealing with reference spurs in any significant way. Given the clock rates
> Ethernet runs at these days, that part should be fairly straightforward.
>
> This *assumes* that there is a crossover somewhere practical between
> the fiber noise and the noise on the optical gear. You should be able to
> work out what it is with some fairly normal phase noise or ADEV testing.
>
> Bob
>
> > On Aug 28, 2021, at 3:03 PM, Dana Whitlow wrote:
> >
> > I was looking for something similar about 18 months or so ago. Although
> I
> > haven't taken any
> > action yet, I concluded that one could do a nice job for under $200 per
> > segment, including the
> > transmitter and receiver modules and lots of connectorized multimode
> > fiber. What I *don't* know
> > is what the phase noise performance would be, except that I do know that
> > the fiber's VF *is*
> > materially influenced by temperature.
> >
> > I was looking primarily at the HFBR-2416 for the fiber receiver, and the
> > HFBR-1412 (standard
> > power) or the HFBR-1414 (high power option) for the transmitter Unlike
> > most of the available
> > models, these are fundamentally analog devices, meaning that you can
> > transmit sinewave
> > 10 MHz through them. At the time I was looking, Mouser was selling these
> > for about $20 each.
> >
> > See the datasheet at
> >
> https://www.mouser.com/datasheet/2/678/AV02-0176EN_2019-02-15-1827546.pdf
> > with particular attention to page 21 regarding the HFBR-2416 receiver.
> >
> > I was also looking at Fiber Instrument Sales for patch cords. We bought
> a
> > lot of fiber stuff from
> > them at Arecibo, and I was always happy with them. See:
> >
> https://www.fiberinstrumentsales.com/catalog-cable-assemblies?gclid=Cj0KCQjwvaeJBhCvARIsABgTDM7eNTkP2nQbyFzhcwDE38VnSEP879MBKV1ZyDq2YrnEtOn7_VfzjbkaAtpfEALw_wcB
> >
> > Somebody had pointed out yet another source of connectorized fibers
> ("patch
> > cords") to me, but I cannot find the name
> > at the moment.
> >
> > Dana K8YUM
> >
> >
> > On Sat, Aug 28, 2021 at 11:52 AM AC0XU (Jim)
> > wrote:
> >
> >> I am hoping that you can help me about a couple of things:
> >>
> >> 1) My time-nuts summaries sometimes appear unformatted and unreadable.
> All
> >> the text from all the postings is crammed together without spacing. How
> can
> >> I fix it?
> >>
> >> 2) I want to distribute 10 MHz references by fiber. There are
> >> RF-over-Fiber products available, but too expensive for me (thousands of
> >> $$$ per xmit/rcv set). I am thinking that it should be possible to use
> >> fiber Ethernet components to do this. I don't mean IEEE 1588 but a much
> >> simpler, no-computer-required, solution. Possibly just converting sine
> wave
> >> (coax) to square wave (fiber) to sine wave (coax). I am looking for a
> low
> >> cost solution. Any thoughts or recommendations??
> >>
> >> Thanks!
> >>
> >> Jim
> >> ___
> >> 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 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
Hi
With a whole variety of pretty good OCXO’s going for cheap money
on eBay, it’s likely less expensive to do cleanup oscillators on the link
compared to going crazy with low noise optical this or that. Yes, you
will be getting something in the high 150’s for noise, but still pretty good
for $10.
If you need better, spend $50 or so on a 10811. Still less money than
some of the crazy fiber stuff.
With either one, send over a high enough frequency that the loop isn’t
dealing with reference spurs in any significant way. Given the clock rates
Ethernet runs at these days, that part should be fairly straightforward.
This *assumes* that there is a crossover somewhere practical between
the fiber noise and the noise on the optical gear. You should be able to
work out what it is with some fairly normal phase noise or ADEV testing.
Bob
> On Aug 28, 2021, at 3:03 PM, Dana Whitlow wrote:
>
> I was looking for something similar about 18 months or so ago. Although I
> haven't taken any
> action yet, I concluded that one could do a nice job for under $200 per
> segment, including the
> transmitter and receiver modules and lots of connectorized multimode
> fiber. What I *don't* know
> is what the phase noise performance would be, except that I do know that
> the fiber's VF *is*
> materially influenced by temperature.
>
> I was looking primarily at the HFBR-2416 for the fiber receiver, and the
> HFBR-1412 (standard
> power) or the HFBR-1414 (high power option) for the transmitter Unlike
> most of the available
> models, these are fundamentally analog devices, meaning that you can
> transmit sinewave
> 10 MHz through them. At the time I was looking, Mouser was selling these
> for about $20 each.
>
> See the datasheet at
> https://www.mouser.com/datasheet/2/678/AV02-0176EN_2019-02-15-1827546.pdf
> with particular attention to page 21 regarding the HFBR-2416 receiver.
>
> I was also looking at Fiber Instrument Sales for patch cords. We bought a
> lot of fiber stuff from
> them at Arecibo, and I was always happy with them. See:
> https://www.fiberinstrumentsales.com/catalog-cable-assemblies?gclid=Cj0KCQjwvaeJBhCvARIsABgTDM7eNTkP2nQbyFzhcwDE38VnSEP879MBKV1ZyDq2YrnEtOn7_VfzjbkaAtpfEALw_wcB
>
> Somebody had pointed out yet another source of connectorized fibers ("patch
> cords") to me, but I cannot find the name
> at the moment.
>
> Dana K8YUM
>
>
> On Sat, Aug 28, 2021 at 11:52 AM AC0XU (Jim)
> wrote:
>
>> I am hoping that you can help me about a couple of things:
>>
>> 1) My time-nuts summaries sometimes appear unformatted and unreadable. All
>> the text from all the postings is crammed together without spacing. How can
>> I fix it?
>>
>> 2) I want to distribute 10 MHz references by fiber. There are
>> RF-over-Fiber products available, but too expensive for me (thousands of
>> $$$ per xmit/rcv set). I am thinking that it should be possible to use
>> fiber Ethernet components to do this. I don't mean IEEE 1588 but a much
>> simpler, no-computer-required, solution. Possibly just converting sine wave
>> (coax) to square wave (fiber) to sine wave (coax). I am looking for a low
>> cost solution. Any thoughts or recommendations??
>>
>> Thanks!
>>
>> Jim
>> ___
>> 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 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
White rabbit seems pretty good for time synced over fiber. PTP with
enhanced stability profile. It's a IEEE standard. It seems to work for
CERN. Lately I've been looking at Cisco devices that can support it. It
whould be nice if I could find hardware that'll support it more easily...
Maybe it'll come soon?
If you need optics I highly recommend AMC optics they'll code (Cisco,
Intel, NetApp) SFP+ and QSFP for any vendor you want. Prices are great and
it's all made the USA no relation to me. I've been getting into 100G
Ethernet over OM4 fiber. The new profile for PTP over fiber is legit.
Bill
On Sat, Aug 28, 2021, 12:04 PM Dana Whitlow wrote:
> I was looking for something similar about 18 months or so ago. Although I
> haven't taken any
> action yet, I concluded that one could do a nice job for under $200 per
> segment, including the
> transmitter and receiver modules and lots of connectorized multimode
> fiber. What I *don't* know
> is what the phase noise performance would be, except that I do know that
> the fiber's VF *is*
> materially influenced by temperature.
>
> I was looking primarily at the HFBR-2416 for the fiber receiver, and the
> HFBR-1412 (standard
> power) or the HFBR-1414 (high power option) for the transmitter Unlike
> most of the available
> models, these are fundamentally analog devices, meaning that you can
> transmit sinewave
> 10 MHz through them. At the time I was looking, Mouser was selling these
> for about $20 each.
>
> See the datasheet at
> https://www.mouser.com/datasheet/2/678/AV02-0176EN_2019-02-15-1827546.pdf
> with particular attention to page 21 regarding the HFBR-2416 receiver.
>
> I was also looking at Fiber Instrument Sales for patch cords. We bought a
> lot of fiber stuff from
> them at Arecibo, and I was always happy with them. See:
>
> https://www.fiberinstrumentsales.com/catalog-cable-assemblies?gclid=Cj0KCQjwvaeJBhCvARIsABgTDM7eNTkP2nQbyFzhcwDE38VnSEP879MBKV1ZyDq2YrnEtOn7_VfzjbkaAtpfEALw_wcB
>
> Somebody had pointed out yet another source of connectorized fibers ("patch
> cords") to me, but I cannot find the name
> at the moment.
>
> Dana K8YUM
>
>
> On Sat, Aug 28, 2021 at 11:52 AM AC0XU (Jim)
> wrote:
>
> > I am hoping that you can help me about a couple of things:
> >
> > 1) My time-nuts summaries sometimes appear unformatted and unreadable.
> All
> > the text from all the postings is crammed together without spacing. How
> can
> > I fix it?
> >
> > 2) I want to distribute 10 MHz references by fiber. There are
> > RF-over-Fiber products available, but too expensive for me (thousands of
> > $$$ per xmit/rcv set). I am thinking that it should be possible to use
> > fiber Ethernet components to do this. I don't mean IEEE 1588 but a much
> > simpler, no-computer-required, solution. Possibly just converting sine
> wave
> > (coax) to square wave (fiber) to sine wave (coax). I am looking for a low
> > cost solution. Any thoughts or recommendations??
> >
> > Thanks!
> >
> > Jim
> > ___
> > 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 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
I was looking for something similar about 18 months or so ago. Although I
haven't taken any
action yet, I concluded that one could do a nice job for under $200 per
segment, including the
transmitter and receiver modules and lots of connectorized multimode
fiber. What I *don't* know
is what the phase noise performance would be, except that I do know that
the fiber's VF *is*
materially influenced by temperature.
I was looking primarily at the HFBR-2416 for the fiber receiver, and the
HFBR-1412 (standard
power) or the HFBR-1414 (high power option) for the transmitter Unlike
most of the available
models, these are fundamentally analog devices, meaning that you can
transmit sinewave
10 MHz through them. At the time I was looking, Mouser was selling these
for about $20 each.
See the datasheet at
https://www.mouser.com/datasheet/2/678/AV02-0176EN_2019-02-15-1827546.pdf
with particular attention to page 21 regarding the HFBR-2416 receiver.
I was also looking at Fiber Instrument Sales for patch cords. We bought a
lot of fiber stuff from
them at Arecibo, and I was always happy with them. See:
https://www.fiberinstrumentsales.com/catalog-cable-assemblies?gclid=Cj0KCQjwvaeJBhCvARIsABgTDM7eNTkP2nQbyFzhcwDE38VnSEP879MBKV1ZyDq2YrnEtOn7_VfzjbkaAtpfEALw_wcB
Somebody had pointed out yet another source of connectorized fibers ("patch
cords") to me, but I cannot find the name
at the moment.
Dana K8YUM
On Sat, Aug 28, 2021 at 11:52 AM AC0XU (Jim)
wrote:
> I am hoping that you can help me about a couple of things:
>
> 1) My time-nuts summaries sometimes appear unformatted and unreadable. All
> the text from all the postings is crammed together without spacing. How can
> I fix it?
>
> 2) I want to distribute 10 MHz references by fiber. There are
> RF-over-Fiber products available, but too expensive for me (thousands of
> $$$ per xmit/rcv set). I am thinking that it should be possible to use
> fiber Ethernet components to do this. I don't mean IEEE 1588 but a much
> simpler, no-computer-required, solution. Possibly just converting sine wave
> (coax) to square wave (fiber) to sine wave (coax). I am looking for a low
> cost solution. Any thoughts or recommendations??
>
> Thanks!
>
> Jim
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send
> an email to time-nuts-le...@lists.febo.com
> To unsubscribe, go to and follow the instructions there.
>
___
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email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Query about List and about 10 MHz Distro
Look at Synchronous Ethernet. On Sat, 28 Aug 2021, 17:51 AC0XU (Jim), wrote: > I am hoping that you can help me about a couple of things: > > 1) My time-nuts summaries sometimes appear unformatted and unreadable. All > the text from all the postings is crammed together without spacing. How can > I fix it? > > 2) I want to distribute 10 MHz references by fiber. There are > RF-over-Fiber products available, but too expensive for me (thousands of > $$$ per xmit/rcv set). I am thinking that it should be possible to use > fiber Ethernet components to do this. I don't mean IEEE 1588 but a much > simpler, no-computer-required, solution. Possibly just converting sine wave > (coax) to square wave (fiber) to sine wave (coax). I am looking for a low > cost solution. Any thoughts or recommendations?? > > Thanks! > > Jim > ___ > 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 8/28/21 9:56 AM, Andy Talbot wrote: When I asked about this on another Group a while back, I was told the phase noise made it an undesirable solution. Although I never tried it, I would imaging balanced shielded twisted pair would be a better way to go. Immune from ground loop problems than can beset coax distribution and a whole raft of ICs support the medium, from RS422 to CAN bus drivers and receivers. Andy www.g4jnt.com We use fiber to distribute high quality 10 and 100 MHz at JPL. I can visualize the rack downstairs from my office where the cables terminate, but I can't for the life of me remember the brand name. It's a 3U card.. DSN does it as well, with obsessive attention to temperature, mechanical stress, etc. From 20 years ago: https://tmo.jpl.nasa.gov/progress_report/42-148/148L.pdf - probably overkill PTS has a Fiber distribution amp: https://www.ptsyst.com/DA1-100-10-FO-B.pdf There's this, but Im going to bet it's pricey: https://emcore.com/products/reference-timing/ On Sat, 28 Aug 2021 at 17:51, AC0XU (Jim) wrote: I am hoping that you can help me about a couple of things: 1) My time-nuts summaries sometimes appear unformatted and unreadable. All the text from all the postings is crammed together without spacing. How can I fix it? 2) I want to distribute 10 MHz references by fiber. There are RF-over-Fiber products available, but too expensive for me (thousands of $$$ per xmit/rcv set). I am thinking that it should be possible to use fiber Ethernet components to do this. I don't mean IEEE 1588 but a much simpler, no-computer-required, solution. Possibly just converting sine wave (coax) to square wave (fiber) to sine wave (coax). I am looking for a low cost solution. Any thoughts or recommendations?? Thanks! Jim ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Query about List and about 10 MHz Distro
On 8/28/21 9:51 AM, AC0XU (Jim) wrote: I am hoping that you can help me about a couple of things: 1) My time-nuts summaries sometimes appear unformatted and unreadable. All the text from all the postings is crammed together without spacing. How can I fix it? 2) I want to distribute 10 MHz references by fiber. There are RF-over-Fiber products available, but too expensive for me (thousands of $$$ per xmit/rcv set). I am thinking that it should be possible to use fiber Ethernet components to do this. I don't mean IEEE 1588 but a much simpler, no-computer-required, solution. Possibly just converting sine wave (coax) to square wave (fiber) to sine wave (coax). I am looking for a low cost solution. Any thoughts or recommendations?? Take a look at the standard fiber optic modules that plug into a switch. They typically have a very simple logic level interface to the diode. here's a $27 dollar example - but I think you might want to iterate around - I recall finding cheaper ones - part of it is which fiber cable/connector you use, and part of it is what the backside interface looks like. I can't find it now, but you can get the mating electrical connector, or you can solder wires. https://www.fs.com/products/11555.html?attribute=77&id=219732 The OVRO-LWA uses fiber to connect the remote antenna preamp with ~1km fiber to the receiver at 30-90 MHz - they use a laser diode on the Tx end and a receiver on the Rx end. They're pretty cheap. They've done quite a bit of testing of various schemes, and measuring noise performance and loss. dig around here: http://www.tauceti.caltech.edu/LWA/lwamemos.html In particular memo 12 http://www.tauceti.caltech.edu/LWA/memos/memo12.pdf - gives a couple part numbers. If you need Sandy Weinreb's report (from 2019, referenced by Larry D'Addario in memo 12) - you could probably email him, or I can look for a copy. ___ 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
When I asked about this on another Group a while back, I was told the phase noise made it an undesirable solution. Although I never tried it, I would imaging balanced shielded twisted pair would be a better way to go. Immune from ground loop problems than can beset coax distribution and a whole raft of ICs support the medium, from RS422 to CAN bus drivers and receivers. Andy www.g4jnt.com On Sat, 28 Aug 2021 at 17:51, AC0XU (Jim) wrote: > I am hoping that you can help me about a couple of things: > > 1) My time-nuts summaries sometimes appear unformatted and unreadable. All > the text from all the postings is crammed together without spacing. How can > I fix it? > > 2) I want to distribute 10 MHz references by fiber. There are > RF-over-Fiber products available, but too expensive for me (thousands of > $$$ per xmit/rcv set). I am thinking that it should be possible to use > fiber Ethernet components to do this. I don't mean IEEE 1588 but a much > simpler, no-computer-required, solution. Possibly just converting sine wave > (coax) to square wave (fiber) to sine wave (coax). I am looking for a low > cost solution. Any thoughts or recommendations?? > > Thanks! > > Jim > ___ > 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.
