| Electronics > Beginners |
| Ethernet cable questions |
| << < (4/4) |
| Psi:
Are you sure the 150 reading is 150ohm? If it was 150k i would expect that you are touching each meter probe to your finger while testing the wire |
| tooki:
--- Quote from: LapTop006 on March 05, 2019, 07:02:59 am --- --- Quote from: tooki on March 05, 2019, 04:24:02 am --- --- Quote from: wraper on March 03, 2019, 06:11:25 pm --- --- Quote from: sal_park on March 03, 2019, 05:55:26 pm ---cat6socket -> cat6 cable (solid core) 10 meters long -> cat6 socket. --- End quote --- What are those sockets? A lot of sockets have built in transformers and termination resistors. --- End quote --- Only the sockets for devices do this. The sockets for wall sockets and patch panels are pure connectors, since they aren’t endpoints. --- End quote --- One common exception is sockets intended for phone use. Even if they're 8p8c / RJ45 (insert argument about naming here). The patch panel shouldn't have any of that, but the wall socket might. --- End quote --- Nope. The jack is just a passive connector. An 8P8C jack only has a transformer in a NIC or network switch (i.e. in places where the signal is being send to a transceiver chip and from there onto wherever the decoded data goes). All the wiring in between is only wired straight through. A wall jack is literally a permanently-wired extension cord, nothing more. POTS phone jacks most definitely could not, and thus would not, have a transformer inline, since that would block the DC line voltage used to power the telephone itself. |
| tooki:
--- Quote from: LapTop006 on March 05, 2019, 07:02:59 am --- --- Quote from: tooki on March 05, 2019, 04:24:02 am --- --- Quote from: wraper on March 03, 2019, 06:11:25 pm --- --- Quote from: sal_park on March 03, 2019, 05:55:26 pm ---cat6socket -> cat6 cable (solid core) 10 meters long -> cat6 socket. --- End quote --- What are those sockets? A lot of sockets have built in transformers and termination resistors. --- End quote --- Only the sockets for devices do this. The sockets for wall sockets and patch panels are pure connectors, since they aren’t endpoints. --- End quote --- One common exception is sockets intended for phone use. Even if they're 8p8c / RJ45 (insert argument about naming here). The patch panel shouldn't have any of that, but the wall socket might. --- End quote --- OK, I did a bit of googling and found some cases where the whole jacks (as in, the wall box) can contain a component: primarily ISDN jacks with built in terminators. ISDN does require terminator resistors on the last socket on a line. But in every example I saw, this was part of the whole wall box, not inside the actual connector itself. (E.g. it's a plain 8P8C connector, with punchdown blocks and the resistor, all on a PCB.) I also saw some British jack boxes with built in spark gaps or surge arrestors, resistors and ring capacitors. But again, on a PCB, not integrated into the connector itself. (I've never seen this anywhere else; I think elsewhere, it was normal to have these components inside the telephone itself.) But this thread is about Ethernet patch panels. The Cat 5/6/7 sockets used for wall jacks and in the patch panels MUST be purely passive, as I said. They're nothing but extension cords. The actual Ethernet endpoints are in the devices that are connected through the wall wiring. |
| Richard Crowley:
Such low resistances make me wonder whether you have your PoE injector (not identified) still in the circuit somewhere? Otherwise it is just completely bizarre. |
| Emo:
Hi, You have mixed up all the colours. look at the bottom of the patch panel. It should have two color schemes a/b In your first picture one row should have only different coloured wires, the four pairs. As you did it there is only the same colour pairs per socket. So follow the colours on the bottom, preferable the /B set Eric Edit; confusing in this situation is that there are roughly two systems. See attached images. Yours might be according to image 1. To be safe you could use a continuity tester to find out the correct pins/colors. Also no explanation for the 150 ohm resistance unless the POE is still attached somewhere a mentioned before |
| Navigation |
| Message Index |
| Previous page |