Two coax jacks?

Posted by: Dignan

Two coax jacks? - 02/07/2016 04:19

I've seen this in several houses now and I don't understand it: a wall plate with one ethernet and two coax jacks.

Nevermind that I think it should be the other way around, what on earth could I need two coax jacks in every room for? In my house there are five rooms with coax, which would require a 10-way splitter which is uncommon and from what I can tell online is generally frowned upon (8-way seems to be the recommended maximum for things like Fios).

I'm going to be terminating cables in a very large house next week, and the cabling installers put two coax lines in every room of this house - 13 rooms! So there are 26 coax cables coming back to their mechanical room. That's insane, right? What the heck is that even for?
Posted by: drakino

Re: Two coax jacks? - 02/07/2016 15:42

Satellite + OTA, or a number of other uses where power might be running over one so a separate run is needed for devices not expecting power on the wire.
Posted by: mlord

Re: Two coax jacks? - 02/07/2016 15:55

Originally Posted By: drakino
Satellite + OTA,

Or STB + Internet. Etc..

When I wired our new home last year, I didn't bother with coax at all,
except for one run directly to the computer room for internet access.

The rest of the place has a plentiful supply of dual Cat5e wall plates.
But even those are mostly unused --> wifi is pretty good around here.

Posted by: jmwking

Re: Two coax jacks? - 02/07/2016 18:24

When we redid our house, we ran coax to the two media stations (we're not big on TVs in bedrooms), and Cat5e to 6 locations (two closets for POE APs, two media stations, an outside mount for a camera, and a bedroom that might be an office someday).

Keeping the primary media stations off the wifi keeps the wifi snappy for devices.

Helped my brother - with four kids streaming on 2 or 3 devices each - do something similar.

-jk
Posted by: tfabris

Re: Two coax jacks? - 02/07/2016 20:54

At one point in history, my DirecTV satellite dish required two coaxial cables running from the set top box to the dish. I think this was for a brief period in DirecTV history. I don't think you need that any more, and I don't think you needed it when DirecTV first came out.

It had something to do with the LNB polarization on the dish in relation to the transponders on the satellites. There was a way you could work around the two-cable need with some sort of in-between multiplexing box, but I never got the box, I just ran both cables.
Posted by: JBjorgen

Re: Two coax jacks? - 03/07/2016 01:35

13 years or so ago when I had Starband (now HughesNet) + DishNetwork, it required two coax connections because there were two LNBs on the dish, one for internet and one for TV.
Posted by: Dignan

Re: Two coax jacks? - 03/07/2016 18:25

Thanks guys, those explanations make sense. My house does have a satellite dish on it (never used it), and the way the wiring all meets looks like it could be for what you describe. It all comes together in one Bell Atlantic box that I don't fully understand, but I do know that it has a coax splitter in the middle of it that does most of the work. Of course, I only have one line in use, making the other 9 unnecessary.

I guess I'm surprised that this brand new house would need two coax to every location. It's also in an area where not a lot of people probably have dishes due to very tall, old trees, and I'm pretty sure Fios is there too. I'll have to figure out how to wire up 13 pairs! I'll probably start with a 2-way splitter - one to the router and one to a 4 or 8-way splitter that will handle the locations they know they'll have TVs on (size of the splitter will depend on how many drops they need live, of course).

Should be interesting!
Posted by: K447

Re: Two coax jacks? - 03/07/2016 19:14

Why energise all the coax outlets? Just hook up the few needed now and have a few extra outputs available in the wiring panel for future moves/adds.
Posted by: jmwking

Re: Two coax jacks? - 03/07/2016 20:07

Originally Posted By: K447
Why energise all the coax outlets? Just hook up the few needed now and have a few extra outputs available in the wiring panel for future moves/adds.


Yeah - as I understand it, every time you split coax you lose some signal strength. You'll likely need a source tweak if you try to make every room live.

-jk
Posted by: gbeer

Re: Two coax jacks? - 03/07/2016 22:25

I still have that Dtv box. The intermediate box is is called a SWIM module. It's built into the dish nowadays.
Posted by: Dignan

Re: Two coax jacks? - 09/08/2016 04:24

FYI, I finished this job and the number of coax cables coming back to the closet was absurd. We only made half of them live (one for each room), but that was still something like 13 cables that we terminated into two 8-way blocks. We brought the main feed into a three-way block, with one connection for the router and the other two for each of the 8-ways, and it all seemed to work just fine. I still think there should have been two ethernet and one coax at each spot, but whatever.

When I actually got on location I saw what the problem was. Clearly, an electrician ran these low voltage lines. He ran every one of them to a full electrical box. This made it very hard to deal with slack, though fortunately (and weirdly) he made them all two-gang boxes. That helped with the cable slack, but it was very weird in the end to see all these double-gang wall plates with just two coax connectors on one side and a single ethernet jack on the other. I have a couple dozen 3-port keystone single gang wall plates in my garage that we could have used if the electrician had just run these to single-gang low voltage boxes.

Anyway, we got the job done and the client is happy. They'll never, ever use those 13 coax cables, but they have them!