[time-nuts] Re: Query about List and about 10 MHz Distro

[Robert DiRosario]

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 <k8yumdoober at gmail.com> 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 <kb8tq at n1k.org> 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 <k8yumdoober at gmail.com> 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.Schatzman at 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
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