Is there any way of sending a satelite feed to its receiver then back again with the satelite signal on it through one cable or will I definitely need send and return cables?

What are the restrictions?

If you are trying to send the RF signal out of the receiver to other televisions in the house, then you can use diplexers.

I have used diplexors when sending televison and radio signals down the same cable but didn't realise you could use them when effectively sending signals in opposite directions on the same cable.

Please explain as I'm not that familiar with the workings of how a signal is carried on a cable.

Thanks

This is really cool.

The diplexers will mix or separate DSS and TV channel signals. Those signals are in completely different frequency ranges, so they will never get mixed. It's kind of a real world example of the paint that they show in cartoons, that paints a black and white checkerboard pattern on the floor right out of the can, and does not get mixed to gray.

And diplexers don't care which way the signals are going, so one can go into it while one goes out.

First, I assume that "satellite feed" means the signal from the LNB to the receiver, and "satellite signal" is the channel three or four output from the satellite receiver. If that is not so, ignore the following and send us an explanation of what you mean.

First, design what you want, ignoring that you only have one cable. Make up a drawing showing where the signals go. Here's the limitation -- design it so that two cables run next to one another -- a "satellite feed" cable runs (in your drawing) next to a "satellite signal" cable. Forget about the direction of travel of the signal. Then, convert this to the real world: everywhere that you have only one cable, use a diplexer to combine or separate the two signals.

Where I say "diplex in" below, I mean I mixed the DSS signal with a cable signal; "diplex out" means I separate them.

I have done this in a totally crazy situation in a client's home: The DSS signal was diplexed on the roof into cable A, was diplexed out on cable B, went around a splitter, was diplexed back in on cable C, then was diplexed out to go to the DSS receiver. Cable A had the DSS signal going down it with a cable signal coming up it, cable B was DSS signal only, used to run the DSS signal around the 8-way splitter, and cable C carried both DSS and cable signal away from the splitter and out to the TV and DSS receiver.

It worked flawlessly.

Wow is that hard to understand.

Ok, there seems to be something wrong in this thread. What exactly are you trying to do? You want to send signal from the sat receiver up to the dish? What precisely do you mean?

Sorry not to be clear about my post (was written in a hurry).
Pretty sure Ernie has grasped what I am trying to do.
I wish to send the signal from the LNB (Satellite dish) down to the receiver where it is decoded (Sky Digital) then take this decoded signal back up the same cable into an 8-way amplifier which distributes throughout the house.

The reason I am trying to do this is because the Satellite receiver was originally in one room with two cables but needs to be moved to another room with one cable (this cable currently being fed by the 8-way amplifier in the roof).
We are simply trying to avoid running another cable as access is awkward.

Sorry to be vague but satellite distribution is a fairly new area for me, although I am learning.

Thanks.

CMO, I would have to say yes, it should work. A diplexer is basically a frequency splitter, kinda like a speaker crossover, except for the addition of the DC-pass to the sattelite connection.

Something like this.

Larry
www.fineelectricco.com

Yup, Larry's artwork has got it.
We tend to organize our thoughts based on the direction of signal flow when we figure out system wiring, so it is kind of a revelation to use one wire for signals going in different directions.

Then again, I still run into guys who insist that a splitter can only split, not combine. This is where taking the time to talk to a vendor's salesman who loves to swap stories can help -- if we understand just what the splitter does, we can figure out how to creatively misuse it.

Sounds like spot-on advice to me.
I was hoping it would be this simple but its amazing how many people say you can't do it.

Thanks for everones help.

Would be as simple as using a diplexor designed to converge SAT and Antenna signals, wouldn't it? Then another one to split?

ItsCold:
Yup. The mindbender is that one signal is going one way and the other, the other. It is really simple once that thought has occurred to you.

Makes me wonder why I ran 2 coax to each location.

You only ran 2? :)

ItsCold:
you probably ran 2 coaxes because you could, so this solution didn't have to occur to you; or because you are a closet genius and you will need to add other signals to those cables in six months, when the new technology makes your present setup obsolete; or maybe you just did not want to stress the electrons in a single cable.

Plus (are you an installer?) installers, or people who think like them, tend to drag all the possible wires they can all at once rather than have to come back later. That sounds like an installer ploy. I have been so convinced that I should do that that I have secretly run additional wires, at no charge, with the required ones, then charged almost an arm and a leg for them when I came back to do an upgrade and I did not have to drill, crawl, feed and yank.