Le 02/01/2022 à 15:50, Bill Buhler a écrit :
Impedance, cat3-> cat6 cabling Impedance is 100 ohms
$1 Chinese adapters seem to be direct-connect of the coax connector to pins 1-2 of RJ45, HI :-) Anyway, it's just a matter of 2:1 balun, so it should be doable easily.
Topology, twisted pair is normally run in a star configuration, but that requires a Impedance matching hub in the middle. You'll need to design and add that to drive multiple devices.
Some existing GPSDO already have several outputs, that should not be a problem. I won't redesign the GPSDO from scratch, I'll probably integrate some existing modules around a RPi or ESP8266 for management.
I've never seen a cheap cat45 to f converter that actually had the right circuits to be clean.
I saw adapters called "baluns" for satellite distribution over RJ45 on electrical equipment catalogs. But if they really contain a balun, it would be for 75 Ohms, so not usable directly.
The other (maybe promising) idea would be to use fiber adapters, that would in the meantime avoid RFI, QRM and ligntning...
Good luck, it sounds like a fun project...
My interest is mostly in digital modes, computing, SDR, satellite, etc... Most of those things require frequency stability, so having a 10 MHz signal available everywhere in the shack seems to be something future-proof :-)
Moreover, "HF over fiber" is also something I am interested in for the future. If the lightning strikes, I'd prefer it to stay outside of the shack :-) Carrying 10 MHz over fiber may be a good start point.
73 de TK1BI