Tv cable question

[toehanus]

Trying to hook up our tv antenna. We had it outside and had it hooked up to a high def coaxial cable that went into the old direct tv junction box outside the house. We decided to move the antenna into the attic. Ran the high def cable into the attic, used an adaptor to connect it to a long non high def cable so that we could put the antennae at the other end of the house. Now we have no channels. If we run the non high def cable directly to tv we have channels, but connected to the high def cable, nothing. So, my question is, can you connect high def and non high def cables?


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[BReeves]

The cable itself really doesn't make any distinction between HD and SD, that is determined in the transmitting equipment. The two common cables used in the home are RG-6 and RG-59, RG-6 is slightly larger and has lower loss, typically used on longer runs. RG-59 is smaller usually used to connect between video components.

You may have a shorted cable, pretty easy to get a strand of the shield shorted to the center conductor if you are not experienced in installing the connectors.

Probably should add. If you are in a fringe area, you reduced the available signal by moving the antenna into the attic and if you ran RG-59 you added more loss. This may or may not keep you from receiving anything but could reduce the number of channels you will receive.

 

[NightShade]

Yeah, if the run is longer there will be more signal loss. On top of that mounting it inside vs outside introduces signal loss along with a splitter cutting the signal as well.

Could do a couple things. Get an antenna that has more signal gain, shorten the cable run, or get an amplifier. Out of the three the amplifier is probably the easiest to do. One of the best things that you can do is remove any unneeded splitters or change splitters that have a high number of ports for one with less. A two port splitter usually cuts the signal to each by about 3.5db the larger splitters will often have one port that cuts the signal by 3.5db and the rest will cut by 7db or more. After that changing out the lines for RG6 will be a big help, http://www.w4rp.com/ref/coax.html Now that channels have went to digital pretty much everything runs between 54 and 687Mhz.

I have a small attic antenna in a closet that has to pull signal through around 10 or 15 walls since I am on the north end of my apartment complex and the broadcast antennas are south of here. I only have a three foot cable from the antenna to an amplifier and it works pretty well. The amp is actually one of the ones that Cox puts in place when they have low signal and need to boost it a bit. One input and three amplified outputs, one power input and one passthrough. If you know someone who cut cable and has one of the amplifiers I would get it. May also find some at a thrift store as well.