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 <[email protected]> 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 <[email protected]> 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 <[email protected]> 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 <[email protected]> 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) <[email protected]> >>>>> 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 -- [email protected] -- To unsubscribe >>>> send >>>>>> an email to [email protected] >>>>>> To unsubscribe, go to and follow the instructions there. >>>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- [email protected] -- To unsubscribe >>>> send an email to [email protected] >>>>> To unsubscribe, go to and follow the instructions there. >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] -- To unsubscribe send >>>> an email to [email protected] >>>> To unsubscribe, go to and follow the instructions there. >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] -- To unsubscribe send >>> an email to [email protected] >>> To unsubscribe, go to and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- [email protected] -- To unsubscribe send an >> email to [email protected] >> To unsubscribe, go to and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe send an > email to [email protected] > To unsubscribe, go to and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
