Argh! I'm trying to rewire some cable through the house from the splitter to a room on the other side using about 150 feet of cable. I read that thin coaxial cable has a maximum transmission distance of 100 meters before significant signal degredation, and I'm confused as to why the cable modem will connect to the network through a 50 feet cable feed but not through 150 feet. Our set-up is as follows:
cable from the box --> splitter --> 150 feet (100 foot segment connected to 50 foot segment) to other side of house (through the attic) --> cable wall jack --> 12 feet to modem --> ethernet to computer
Usually, the modem will pick up pings from the network in about 5 seconds, but with the rewiring, the cheap RCA piece-of-crap just flashes the "On" and "Pc-link" lights for a while, and sometimes seems to reset itself spontaneously. Perhaps the signal is too noisy or too weak...maybe I should install a piece of equipment to boost the signal or reduce line noise. We just spent a couple hours drilling holes in the house, and now it doesn't work. I'd like to avoid calling a cable tech who will probably charge a lot of money and be somewhat inept (just a generalization--sorry any cable techs!).
I am thinking that maybe I should get a signal tester for this and other projects. What is a good model and how much do they cost?
Any help, suggestions, insults, electronics tips or caveats would be appreciated. Thanks!
P.S. May you stand strong in these times of trouble.
cable modem madness
Have the cable guy come out. I dunno if they will charge or not, you should check. The cable guys usually do know about running cable and signal levels, that's why they are the cable guy after all. 
They aren't PC techs and that's where they are usually over their heads. You could add an amp or this or that but for you it will only be a guess as to if it is really good or not. The cable guy will have the equipment to measure the signal.
They aren't PC techs and that's where they are usually over their heads. You could add an amp or this or that but for you it will only be a guess as to if it is really good or not. The cable guy will have the equipment to measure the signal.
You are simply trying to run the cable too far. There are physical limits to what you are trying to do. The signal is degrading too much before your cable modem can get to it.
You could put an amp on the line, but it would not be worth the cost of an amp that is nice enough for your cable modem to work well. Remember that the signal is bidirectional, so an amp is probably not the answer, anyhow.
You need to either buy some really nice coax (and risk the same problem) or run Cat5. I suggest cat5, as it is rated to go further than coax. I think you have at least 300 feet before you run into Cat5 signal problems. Since the modem is only 10 Mbit ethernet, you shouldn't have any problems. When I first got to college, we ran cat5 all the way down the dorm hall to network our PC's. The big length that went hub-to-hub was around 325 feet. We had very few problems with it.
Oh, and you can save a ton of money on Cat5 if you go to a big cable supplier. When we networked our hall at school, we got a 1000 foot spool for $100 (US). You can buy a decent crimper for $15-$25, and ends for around $0.05 a piece. You will pay MUCH more if you go to a computer store. Just check the yellow pages for a cable manufacturer/wholesaler.
Once you get set up, you can charge your friends $0.25/ft for patch cables. You are making up your own cost, and saving them money.
You could put an amp on the line, but it would not be worth the cost of an amp that is nice enough for your cable modem to work well. Remember that the signal is bidirectional, so an amp is probably not the answer, anyhow.
You need to either buy some really nice coax (and risk the same problem) or run Cat5. I suggest cat5, as it is rated to go further than coax. I think you have at least 300 feet before you run into Cat5 signal problems. Since the modem is only 10 Mbit ethernet, you shouldn't have any problems. When I first got to college, we ran cat5 all the way down the dorm hall to network our PC's. The big length that went hub-to-hub was around 325 feet. We had very few problems with it.
Oh, and you can save a ton of money on Cat5 if you go to a big cable supplier. When we networked our hall at school, we got a 1000 foot spool for $100 (US). You can buy a decent crimper for $15-$25, and ends for around $0.05 a piece. You will pay MUCH more if you go to a computer store. Just check the yellow pages for a cable manufacturer/wholesaler.
Once you get set up, you can charge your friends $0.25/ft for patch cables. You are making up your own cost, and saving them money.
- p o o p
-
FlyingPenguin
- Flightless Bird
- Posts: 33161
- Joined: Wed Nov 22, 2000 11:13 am
- Location: Central Florida
- Contact:
150 feet isn't really all that far BUT you need to do it right:
- You need GOOD wire. The crap they sell in the average store won't do. It should be RG-6 coax. Radio Shack may carry it (not sure - they probably only sell RG-59). Try a mom & pop satelite TV shop and tell them you want RG-6 and that you want the GOOD stuff (explain what you're doing and that you're concerned about signal loss). Use a scrap piece of RG-6 for the jumper from the wall jack to the modem as well. No point using good cable most of the way and a P.O.S. wire the last 3 feet.
- You MUST split the signal for the modem at the EARLIEST point where the cable first enters the house. Each splitter knocks 6 db off the signal. It adds up. The first spitter should also be a 2 way if possible and not a 3 or 4 way. You reduce the signal at the splitter by the number of taps (4 taps reduces the signal strength by 75% - each tap gets 25% - which is a LOT of signal loss). If you need more taps for your TVs then use a 2-way splitter FIRST to tap off the modem line, then put another splitter on the other tap of the 2-way for all your TVs. That way the modem gets 50% of the signal strength and the TVs all share the remaining 50%.
- DO NOT use a cable TV surge suppressor (a surge supressor that the coax connects through). I found out the hard way that cable modems don't like this.
- DO NOT use an RF amplifier. The kind you buy at Radio Shack or Walmart won't work with cable modems.
- DO NOT run the coax near any electrical noise souces (electical motors like the AC fan or flourecent light fixtures).
- Are you using a clean tap on the splitter? If the tap was vacant previously and uncovered, and it's outside or in the attic it may be corroded. Replace the splitter - they're cheap (maybe $5). Buy a good one with gold plated contacts at a satelite shop (not Radio Shack - their splitters are junk).
- Are you getting a strong signal to the house, or you getting a lot of snow on your TVs? If the signal is weak to start with, the additional 150 ft of cable will only degrade it more. You may need to have the cable company look at it.
- You may have a bad connector on your cable. If you crimped your own cable connectors and you've never done it before, it's easy to screw them up. Make sure that the foil wrapper around the inner core is NOT touching the center conductor. You also do not want to squash the center insulator when you strip it (and unless you strip wires for a living it's hard to do it with without squashing it). Use a razor knife to cut around it and then pull it off.
Better yet, if you buy some RG-6 from a satelite shop, have THEM crimp the connectors for you.
- Have you tried connecting a TV to the cable to see if it's getting a decent signal? If there's a lot of snow then the signal is weak and keep in mind that the modem is going to be fussier than a TV when it comes to signal strength.
If it still won't work, I would recommend as Shaggy does, to leave the modem closer to the cable entry point and run CAT5 the rest of the way. Might even be more cost effective as CAT5 cable may be cheaper than RG-6 coax.
I had to do that in my house. The signal was poor in my computer room AND the modem was interfering with the TV in my bedroom. I moved it to the living room where the signal is much stronger and ran CAT 5 from there. 150' is okay for CAT5 as long as you avoid electrical noise sources.
Hope this helps.
- You need GOOD wire. The crap they sell in the average store won't do. It should be RG-6 coax. Radio Shack may carry it (not sure - they probably only sell RG-59). Try a mom & pop satelite TV shop and tell them you want RG-6 and that you want the GOOD stuff (explain what you're doing and that you're concerned about signal loss). Use a scrap piece of RG-6 for the jumper from the wall jack to the modem as well. No point using good cable most of the way and a P.O.S. wire the last 3 feet.
- You MUST split the signal for the modem at the EARLIEST point where the cable first enters the house. Each splitter knocks 6 db off the signal. It adds up. The first spitter should also be a 2 way if possible and not a 3 or 4 way. You reduce the signal at the splitter by the number of taps (4 taps reduces the signal strength by 75% - each tap gets 25% - which is a LOT of signal loss). If you need more taps for your TVs then use a 2-way splitter FIRST to tap off the modem line, then put another splitter on the other tap of the 2-way for all your TVs. That way the modem gets 50% of the signal strength and the TVs all share the remaining 50%.
- DO NOT use a cable TV surge suppressor (a surge supressor that the coax connects through). I found out the hard way that cable modems don't like this.
- DO NOT use an RF amplifier. The kind you buy at Radio Shack or Walmart won't work with cable modems.
- DO NOT run the coax near any electrical noise souces (electical motors like the AC fan or flourecent light fixtures).
- Are you using a clean tap on the splitter? If the tap was vacant previously and uncovered, and it's outside or in the attic it may be corroded. Replace the splitter - they're cheap (maybe $5). Buy a good one with gold plated contacts at a satelite shop (not Radio Shack - their splitters are junk).
- Are you getting a strong signal to the house, or you getting a lot of snow on your TVs? If the signal is weak to start with, the additional 150 ft of cable will only degrade it more. You may need to have the cable company look at it.
- You may have a bad connector on your cable. If you crimped your own cable connectors and you've never done it before, it's easy to screw them up. Make sure that the foil wrapper around the inner core is NOT touching the center conductor. You also do not want to squash the center insulator when you strip it (and unless you strip wires for a living it's hard to do it with without squashing it). Use a razor knife to cut around it and then pull it off.
Better yet, if you buy some RG-6 from a satelite shop, have THEM crimp the connectors for you.
- Have you tried connecting a TV to the cable to see if it's getting a decent signal? If there's a lot of snow then the signal is weak and keep in mind that the modem is going to be fussier than a TV when it comes to signal strength.
If it still won't work, I would recommend as Shaggy does, to leave the modem closer to the cable entry point and run CAT5 the rest of the way. Might even be more cost effective as CAT5 cable may be cheaper than RG-6 coax.
I had to do that in my house. The signal was poor in my computer room AND the modem was interfering with the TV in my bedroom. I moved it to the living room where the signal is much stronger and ran CAT 5 from there. 150' is okay for CAT5 as long as you avoid electrical noise sources.
Hope this helps.
---
“The Government of Spain will not applaud those who set the world on fire just because they show up with a bucket.” - Prime Minister of Spain, Pedro Sánchez
“The Government of Spain will not applaud those who set the world on fire just because they show up with a bucket.” - Prime Minister of Spain, Pedro Sánchez