# Signal loss and ground loops in 75-ohm cable splitters **URL:** \ **Category:** Factual Questions\ **Created:** [February 19, 2005, 10:37pm UTC](https://boards.straightdope.com/t/signal-loss-and-ground-loops-in-75-ohm-cable-splitters/290953 "2005-02-19T22:37:08Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Jurph](https://avatars.discourse-cdn.com/v4/letter/j/50afbb/32.png) [@Jurph](https://boards.straightdope.com/u/Jurph)\ **Post date:** [February 19, 2005, 10:37pm UTC](https://boards.straightdope.com/t/signal-loss-and-ground-loops-in-75-ohm-cable-splitters/290953/1 "2005-02-19T22:37:08Z")
I’m considering getting myself a Hauppauge PVR card for my computer, but I need a quick tutorial on the basics of 75-ohm coaxial cables. Because I use a cable modem, there is a convenient cable with TV signal right next to my computer. My questions are: 1. Can I use a commercial off-the-shelf (COTS) cable splitter, e.g. from Radio Shack, and run one half to my PC and the other to my cable modem? 2. Do I need to ground the “grounding screw” that splitters seem to come with? 3. My cable modem connects (through a router) to a PCI ethernet card; my Hauppauge card will also be a PCI card. Is there any danger of a ground loop or interference? ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [February 19, 2005, 10:46pm UTC](https://boards.straightdope.com/t/signal-loss-and-ground-loops-in-75-ohm-cable-splitters/290953/2 "2005-02-19T22:46:16Z")
Make sure you get one spec’d for cable frequencies (some aren’t). [Like this one](http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=15-2587) Re grounding screw. No that’s kind of unnecessary for your use. RE reducing interference, your best bet is to use factory molded cables where you can instead of splicing, unless you’re really good at making cables properly. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [February 19, 2005, 10:56pm UTC](https://boards.straightdope.com/t/signal-loss-and-ground-loops-in-75-ohm-cable-splitters/290953/3 "2005-02-19T22:56:30Z")
1. Yes, usually. Radio Shack is pretty overpriced on them, but they’re convenient. I’ve seen them in mail-order catalogues, both paper and online; but you have to wait a week, and/or there are minimum order amounts\*. 2. No, the cable will have been grounded per the NEC when the original installation tech ran the line into the building. I’ve never grounded any indoor splitters - as long as the line is grounded properly (and it wouldn’t hurt to check that it is ), you’re safe. 3. Not that I tell. As long as your connectors are properly crimped and tightly screwed on and there aren’t any crimps, fraying, sharp bends or other damage to your cables, there shouldn’t be any problem with ground loops or interference. - - On preview, what **astro** said about frequency response applies, as well. ---
**Author:** ![Jurph](https://avatars.discourse-cdn.com/v4/letter/j/50afbb/32.png) [@Jurph](https://boards.straightdope.com/u/Jurph)\ **Post date:** [February 20, 2005, 9:31pm UTC](https://boards.straightdope.com/t/signal-loss-and-ground-loops-in-75-ohm-cable-splitters/290953/4 "2005-02-20T21:31:21Z")
Alright, so how much trouble am I in if I got [this one](http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=&product%5Fid=15%2D1234&site=search) instead? The connector is F-type, but I noticed that the splitter in my living room says “5-1000 MHz” which mine does not. Will it compromise my internet connection? Am I better off just going back tonight with the receipt and getting an exchange? ---
**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\ **Post date:** [February 20, 2005, 9:46pm UTC](https://boards.straightdope.com/t/signal-loss-and-ground-loops-in-75-ohm-cable-splitters/290953/5 "2005-02-20T21:46:52Z")
> [@Jurph](#): > > Alright, so how much trouble am I in if I got [this one](http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=&product%5Fid=15%2D1234&site=search) instead? The connector is F-type, but I noticed that the splitter in my living room says “5-1000 MHz” which mine does not. Will it compromise my internet connection? Am I better off just going back tonight with the receipt and getting an exchange? The specifications say that it is good to 890 MHz, which should be more than enough for any cable system.