2 Jan
2022
2 Jan
'22
3:39 p.m.
Regarding distribution by fiber optics, that should also be no problem.
But you kind of need to build your own system.
Take a look at SPDIF/TOSLINK optical emitters and receivers. There are
low cost modules available for up to 10Mbps using standard 650nm TOSLINK
plastic fibers (e.g. TORX/TOTX 135XA series from Toshiba at a cost
around 25 euro a pair). Since you only need to transport a reference
clock, basically a square wave, there should not be a problem using them
in an extreme simple schematics for distances up to a few tens of meters.
But of course, costs will not be in the 1€ rand like the Alibaba balun.
But there are also Chinese sources going down to less than $1 per
optical transceiver in a 100pcs range.
Marius, YO2LOJ
On 02/01/2022 19:59, Rob PE1CHL via 44Net wrote:
On 1/2/22 3:17 PM, Toussaint OTTAVI via 44Net wrote:
But I'd like to be able to carry 10 MHz
reference signal to various locations in the shack over network cabling. My first idea is
about using existing converters for TV/SAT :
- RF to Ethernet passive couplers (a F connector tied to pins 1-2 of a RJ45 connector, $1
on Chinese warehouses).
- RF to fiber adapters (such as those used in FTTH/CATV). But a first look shows
frequency range is 50-1000 MHz.
I have not handled that particular scenario. What
we have done (at least temporarily):
- used commercial "video distribution amplifiers" from the old analog video
days to split the 10 MHz signal over several coax outputs. works fine.
- used "coax to utp baluns" from China (intended to use oldfashioned analog
cameras over UTP wiring). also worked fine while we needed it. I think that is what you
meant with the first option?
So I guess the combination of these two will also work.
Video stuff is of course specifiied for the 0-6 MHz range but as long as there is no
intentional lowpass filter in them, it will work at 10 MHz.
Of course the CATV baluns do not work well for the purpose they are intended for, but for
10 MHz it does not really matter.
But I think using coax is the better option, it tends to radiate (and pickup
interference) less than UTP.
Rob
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