Cable Modem woes

[nst6563]

Ok...here's the situation...

I have 3 machines hooked into a d-link wireless g router. 2 are via LAN cable, the 3rd by wireless. Router is hooked to Cable modem. All works ok with that setup.

Here's where I'm having some issues...
The same line that the Cable comes in on, we also have Satelite. starting from outside:

Outside:
Cable Line + Satellite > Diplexer (combines cable + satellite into one cable for entering the house) > single RG6 into house.

Inside:
RG6 > Diplexer (seperates Sat and Cable into seperate lines) > Cable and Sat.
On the Cable output of Diplexer, it goes to a splitter and splits to Cable modem and Cable box. Satellite output obviously goes to Satellite reciever.

That setup doesn't work.
What happens is that it all works fine...until I plug in the RG6 to the Satellite reciever. Once I plug the satellite receiver in, the Cable modem drops.

Is there a solution to this? I'd prefer NOT to make everything wireless since one of the PC's is an HTPC. The next closest "open" cable line is upstairs, and my wireless signal drops in half if I move the router and cable modem up there.

Are there diplexers and such that work with a cable modem? I suspect that the cross-traffic from the Satellite's LNB and the bi-directional data from the cable modem are interfering with each other.

 

[tdg]

I'm not famaliar with combining satelite & cable, but probably what you need to do is put a high pass filter on the incoming cable line, before it combines with the satellite. This way all the high frequencies are sent to the TV's, and upstream frequencies are blocked from going back towards the cable modem/ISP.

 

[Lowbatt]

I'm not famaliar with combining satelite & cable, but probably what you need to do is put a high pass filter on the incoming cable line, before it combines with the satellite. This way all the high frequencies are sent to the TV's, and upstream frequencies are blocked from going back towards the cable modem/ISP.

if you block the upstream your cable modem wont work. Honestly I doubt that there is any way to use the diplexer. I'm sure its cross interference or something causing the modem to drop. I'd suggest just running a cabler line directly to where you want the modem to be. You could also try removing the cable splitter and see if that modem still drops off. It could jsut be loosing too much between the diplexer and the splitter.

 

[nst6563]

running a direct cable line isn't an option (renting).
I've tried without the diplexer and same thing happens...as soon as the sat is plugged in, the cable modem drops.

For now I just moved the cable modem and wireless router upstairs. Put wireless adapters on the other 2 machines (and I can't stand it...friggin' slow and the connection rate is horrendous...I get anywhere from 1mb to 36mb on my machine. The other machines get the full 54mb all the time. Tried different adapter and router too...guess it's just a location problem).

I'm still open to suggestions though...ANYTHING to get me back on a cat5 connection since it seems the room my computer is in acts like a farraday cage.

 

[Duster]

So you have two incomening signals on the same line. not going to work

And you only have 2 cable ports in your hhouse and your unwilling to move the cable modem to the second outlet well your going to have to run your own line then. You could prob run a line outside the house to a window then move inside to the Sat. Would be getto but would work. Other wise get some wifi signal boosters so wifi works down stairs.

 

[nst6563]

So you have two incomening signals on the same line. not going to work

Actually, it can work, just prolly not with a cable modem and satellite. I had it working fine before with a satellite and digital cable, but there's something thrown into the mix with a cable modem that it doesn't like.

Putting two signals onto the same line happens all the time especially in telecommunications, it's called multiplexing. A device sits on each end of the cable, one that combines the signals to send and the other to recieve the signals and seperate them.