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In my house there is a wall outlet with 2 coaxial cables coming out. Why 2? I saw there some sort of service that needs double bandwidth?

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closed as off-topic by duskwuff, R Drast, Voltage Spike, Dmitry Grigoryev, Kevin Reid May 25 '18 at 18:14

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  • \$\begingroup\$ One cable, one antenna? No idea. You'd need to be more specific (e.g. picture, context, country). \$\endgroup\$ – Tom Carpenter May 19 '18 at 9:32
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    \$\begingroup\$ One incoming, one to feed another socket... \$\endgroup\$ – Solar Mike May 19 '18 at 9:36
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    \$\begingroup\$ They used to have one for TV and one for radio. At least our house (Netherlands) had two different antennae and two cables. \$\endgroup\$ – Oldfart May 19 '18 at 9:48
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    \$\begingroup\$ Possibilities: 1) very very old analog cable systems once used dual cable, 2) an inlet and outlet, 3) satellite TV DVR’s that need constant connection to both horizontal and vertical poles. \$\endgroup\$ – Tyson May 19 '18 at 15:40
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    \$\begingroup\$ Outlets with two coaxial connectors were used once upon a time for 10Base2 ethernet (e.g. amazon.com/White-Female-Connectors-Solder-Wallplate/dp/…) \$\endgroup\$ – Jules May 19 '18 at 18:49
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If it looks anything like the one in this image, it is likely just for historical reasons. At least here in Belguim, they are pretty much always just wired in parallel internally.

When everything worked with antennas, you would be able to use a different antenna (and perhaps cable, see note) for the FM radio band than the TV band. The connector for radio is different from that of TV, so you can't plug the TV into the radio cable and vice-versa (it wouldn't damage anything, just wouldn't work). Now this is pretty much always done over just one coaxial cable, and the same coaxial cable carries both FM radio and TV signals (sometimes also other things like phone signals and internet, through standards such as DOCSIS). To support the different applications they still have two connectors, but internally they connect to the same wire.

enter image description here

Image source (Niko Product page)

Note: They would use different cable not because one cable didn't work at both frequencies, but to avoid issues with power combiners.

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My house (in the US, built in early 2000's) has 2 coax cables running to nearly every room. There is a central wiring cabinet in the house that has all the cables running to it: 20 or so cables; 10 rooms, each w/ 2 cables per room. What I connect them to in the wiring cabinet is up to me. The wiring cabinet also has the "outside" cables going into it (cables from the street, from satellite dishes, etc.).

In my case I have DirecTV satellite TV, which uses just 1 coax cable, so I have just 1 coax wire connected to each room.

However, the previous owner of this house had Dish (a different satellite TV) and Comcast (a cable TV provider) connected to each room, so they used both cables in each room.

Older DirecTV setups required 2 coax cables to each receiver, which would also have used all the cables at once.

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