Ethernet over coax question...

dabflyboy

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OK, this is a dumb question, but I really just don't know the answer. My garage is about 70ft away from my house, and it has a coax cable running to it via direct burial (no conduit). I have no idea what the previous owner used it for. I bought a coax tester to test the viability of using it for a POE camera via the POE ethernet-over-coax adapters that Andy sells. When testing the line it came back saying the center conductor is shorted to the insulation, but I have no idea where. I REALLY don't want to have to dig that thing up.....sooooo what exactly would happen if I connected a camera to it via POE anyway? What's the worst that could happen? Thanks.
 
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TonyR

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OK, this is a dumb question, but I really just don't know the answer. My garage is about 70ft away from my house, and it has a coax cable running to it via direct burial (no conduit). I have no idea what the previous owner used it for. I bought a coax tester () to test the viability of using it for a POE camera via the POE ethernet-over-coax adapters that Andy sells. When testing the line, it came back saying the center conductor is shorted to the insulation. What exactly would happen if I connected a camera to it via POE anyway? What's the worst that could happen? Thanks.
If the POE switch or POE injector is truly 802.3/af or /at rated, nothing....it just would not work. The PD (cam) cannot talk to the PSE (POE power supply) so it won't switch on.

Have you inspected both ends? At worse, cut off both ends, insure outer shield is not touching center or earth, using a DVM or analog multi-tester on Rx100K or Rx10K check at one end for any continuity between the 2 (don't touch either with fingers or body while measuring). If any resistance read, then it's likely cut and shorted underground.
 
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dabflyboy

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If the POE switch or POE injector is truly 802.3/af or /at rated, nothing....it just would not work. The PD (cam) cannot talk to the PSE (POE power supply) so it won't switch on.

Have you inspected both ends? At worse, cut off both ends, insure outer shield is not touching center or earth, using a DVM or analog multi-tester on Rx100K or Rx10K check for any continuity between the 2 (don't touch either with fingers or body while measuring). If any resistance read, then it's likely cut and shorted underground.
Ok cool, thanks. I only took a quick look at the ends when connecting the tester to them. The other end of it terminates on the side of the house where there is a cable distribution box/amplifier, but it was just hanging freely and not connected to it. I'm guess once upon a time they may have had a TV out there?

I think I have some twist on RG6 cable connectors in a toolbox from years ago, so I'll give that a try along with the resistance test.
 

bp2008

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If the cable turns out to be okay with new connectors, I'd just install regular gigabit ethernet over coax adapters, and use it to feed a PoE switch in the garage. Then you can have multiple cameras, a TV, or PC, or wifi access point or whatever you like, and not be limited to just one device and also not need to worry about sending PoE power down the coax cable.
 

dabflyboy

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That's a solid idea. I'll probably end up doing just that. Thanks. Hopefully I won't have to run new cable.
 

dabflyboy

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Well, that coax is defunct. I even tried connecting one of our small TV's to it after connecting the other end to the amplifier/splitter box. Nada. Looks like I'm going to have to dig it up and lay some conduit. We have pocket gophers, and I wonder if they've chewed on the line. Thanks for the help.
 

tech_junkie

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Well, that coax is defunct. I even tried connecting one of our small TV's to it after connecting the other end to the amplifier/splitter box. Nada. Looks like I'm going to have to dig it up and lay some conduit. We have pocket gophers, and I wonder if they've chewed on the line. Thanks for the help.
If you have power at your garage, I would recommend just setting up a pair of ubiquity nanobeams.

These are not wifi, as its a wireless layer2 transport. The real term for it is RFIP The citizen bands are 5Ghz and 60Ghz.
 
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I went the easy route (and cheaper) by installing these.


Along with an inexpensive 4 Port POE+ switch with an uplink port. This handles 3 2K Dahua cameras and 1 5MP Panoramic Dahua camera without any bandwidth issues. It all comes back up after a power outage and is dead reliable. Of course, this only works if your garage AC circuit is on the same phase as the house AC circuit you plug the adapter into.
 

TonyR

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I went the easy route (and cheaper) by installing these.


Along with an inexpensive 4 Port POE+ switch with an uplink port. This handles 3 2K Dahua cameras and 1 5MP Panoramic Dahua camera without any bandwidth issues. It all comes back up after a power outage and is dead reliable. Of course, this only works if your garage AC circuit is on the same phase as the house AC circuit you plug the adapter into.
TL;DR: So if you're about to try a pair of PLA's, insure they comply with the G.hn specification.

Got nothing better to do or are curious:

I've used the old X-10's of the 80's and some of TP-LINK's PLAs over the years and they can work great but along with what you said, they must be on the same side of the phase (in the U.S., a split-phase, 120/240 3-wire residential service) in order to operate. If there's some capacitive coupling perhaps when a 240VAC device like an electric dryer or electric water heater is operating they may work marginally or still, not at all. So too often they just won't work or are troublesome for the application.

Enter the G.hn spec for these PLAs circa 2012 where they claim to work on any wire in the house, same phase or not, and only caution about placing on a surge protector or next to "high powered electrical devices such as refrigerators, air-conditioners, microwave ovens, etc."

I cannot attest to how well these newer G.hn specs work but will likely have that opportunity soon. In the mean time, I posted this info in case someone is considering going with a pair of PLAs to solve an issue trying to provide Ethernet access to a remote barn or garage/shop that has power supplied by the house but have held back because it's not on the same leg/phase as the house and they couldn't get the PLAs to work (weren't of the G.hn spec). So if you're about to try a pair of PLA's, insure they comply with the G.hn specification.

I can't specifically or personally recommend a device but I do know that Comtrend was on-board early and even has a version that provides POE. Also, zYxel has some G.hn-spec'd PLAs. I have an older pair of zYxel PLAs running in a customer's 2 story home for 6 years now without a hiccup.

Below are links to manufacturer info, both Comtrend and zYxel can be found at amazon and other online retailers.
 

Nick70068

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Just be aware that some of the powerline ethernet adapters can trip a Combination arc fault circuit interrupters (CAFCI). I had to get rid of my TP-Link because it would sporadically trip my Siemen's CAFCI 30 amp breaker. So I decided to go with an old router running DD-WRT setup as a wireless bridge to my main router.
 
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