Does a cable splitter affect quality when not connected to a device?

Question

I have one cable line coming from the wall to a 2 way splitter, one end goes to the modem, the other to my tv. I recently put a second splitter on the tv line, to put a second tv in my living room to watch two football games on Sundays. I noticed when both tv's were on, the signal was fine on both sets. But when I disconnected the second tv, leaving the splitter in but only connected to the first, I would lose quality on my main tv on the first few channels. I thought that a splitter only degraded the signal when it was actually connected to a device, otherwise it pretty much acts like a female-female connector. Am I correct or wrong?

Answer 1

First, the other answers that tell you to terminate an unused splitter output leg (or cable line attached to it) with a resistor cap are 100% correct. You can buy a package of them cheap any place that TV antenna accessories are sold, like the electrical department of a big hardware store. Failure to do so can cause reflections back to the splitter than can have unpredictable effects on its other legs, none of which are good.



But there's more: if I've read your question correctly, you've installed a second 2-port splitter at the output leg of your first splitter. That inserts more loss than necessary in the output ports of the second splitter. In very simplistic terms, the output of your second splitter is down to less than 25% of the power level of your cable input. What you should do instead is retire both 2-port splitters and replace them with a single 3-port splitter. That would raise your minimum signal level at each output to a little under 33%. That still sounds like too much loss, but it should work okay with almost any cable system. I ran a 4-port splitter for years with no problems.

Answer 2

As another stated the standard 2-way splitter will decrease the signal by 3.5db. Split that again and you'll get a loss of 7dp, which is what you'll get if you use a 4-way splitter. The more you split, the more it degrades the signal. A true female to female connector (f-81 or barrel connector) will degrade your signal by about 1db, maybe less, but there is loss. The longer your cable the more loss you'll get too.



Why would you get poorer signal when you have the other line disconnected? A few things may be happening here. Interference may leak into the line if it's not plugged into something, but more than likely the second unit is grounding the splitter/cable better than your main TV/receiver. If the splitter is made for satellite and you're not using it for satellite one "leg" of that splitter will pass power while the other won't. You could try switching "legs" to see if that has any affect.

Answer 3

An un-connected output from a splitter can cause reflections back into the cable. This shows up as ghosting and other issues.



Radio shack sells "Resistor Caps" that act like something is attached. But the splitter always cuts the signal strength in half so if this becomes a problem you might want to consider an amplified splitter.

Answer 4

Splitters always degrade signal, the first few channels have lower signal quality usually anyway, and i have no clue as to why you weren't receiving a degrade with both TVs hooked up but one when one was disconnected, that goes against logic on how splitters work, if the splitter had a booster that would explain one, but it would also kind of make the other one even more confusing.

Answer 5

Don't use more than you actually need in splitting.. There is a 3.5 db. loss in signal strength through each splitter. If any connections are left open, they should be terminated with the proper impedence terminator plug.. (or you might get ghosting or other strange effects.) Also if you leave a long cable connected to a splitter, but going nowhere, it will affect your TV service also...

Answer 6

4 Way Splitter Loss

Answer 7

If you use a powered splitter for the tvs it will not matter if you disconnect a tv. There is no signal loss and complete isolation between the ports. the passive splitters always cause a loss.

Answer 8

Radio (and TV) frequency signals can reflect from unterminated cables, depending on the length in relation to signal wavelength, this can subtract from the original signal, or have little effect. So a splitter with one side unused, can have higher losses, even though that sounds counter-intuitive.



Professional cable installations use a terminator (dummy load) on unused ports.

Answer 9

I'm not certain about the signal in your situation, but some signals (like DMX) degrade if they aren't terminated properly. It may be that the open connection is causing an issue, and connecting anything to that terminal would improve it.

Answer 10

You need to get a wifi card or USB wifi dongle for your new desktop. That will allow you to connect to your router and the Internet.

Answer 11

It depends