Coax Splitter/Amplifier

[frntchr]

Greetings,

I'm having issues with my high speed internet. About 2-3 times a month, my cable modem loses its signal which, in turn, disables my internet and Vonage. I then have to fiddle [insert your own f-word] with it until I get a signal.

I've read on these forums that it's the quality of equipment that I have (Charter's Ambit modem) and that it doesn't like to receive a split signal. I've verified this by running a barrel connector direct from the main feed to the cable modem. When I put the splitter back on, it'll work for a while, then I wrestle with it until I get a good signal.

Question 1: would amplifying the signal help?

Question 2: what are decent cable amplifiers out there?

Current setup:

Main -> Y-split -> 1 goes to Cable modem
-----------------> 2 Rest of house (5-port splitter)

 

[rcdallas]

You don't want a amplifier to boost signals to your cable modem, that is not a fix.

You might have a bad drop (line from tap to house) or possibly a bad port on the tap, or even hard line troubles. If you have good picture quality on basic cable all channels on all tv's, without a meter, I would have to say possibly a return issue, one way to test that is with a digital cable box using interactive feature such as on demand. When the cable modem goes out, play with on demand, if nogo then I bet it is a return problem.

If you are more then 100' from the TAP, you are supposed to have RG-11 NOT RG-6.

The way you described your setup is the correct way to have it installed.

 

[dishrich]

Your 2-way splitter could have gone bad; it does happen.
Make sure that if you try changing it, it's rates 5-1000 mhz.

But, as rc points out, it sounds like you have problems that are NOT in your house. (ie: Charter's problem) I just went through this with Insight last summer with my modem dropping from the network - it turns out Insight has had MANY of their tap-boxes in Springfield go bad on the return side, as well as the low band (ch's 2-6) looked like crap. They came out to my house, changed the tap-box in my pedestal in 5 min & I haven't a problem since. (as well as my low-band looks a lot better)

 

[rcdallas]

In an ideal world, the tech will take his fancy meter and troubleshoot that by means of divide and conquer then call for a line tech. If you get a lazy "cable dawg" they'll tell you that you need to go out to Lowe's, buy a compression tool and fittings and replace all the fittings in the house then say sign here. Trust me I've seen that.

 

[Todd Humphrey]

The splitter and length of cable are not an issue as long as you have enough signal. If you do not have enough signal, then removing the splitter doubles the signal. Since signals are measured on a log scale, doubling is not much of an increase, but if you are on a threshold, it can make the difference.

TV is a one way signal, whereas cable modem is a two signal. If you have an amp not rated for cable modem use, you are going to have problems. One solution is to split the signal with a 2-way amp, run one run to your cable modem, the second to the amp for distribution to your TV's

Bottom line, this is your cable co problem and they should fix it.

 

[stevo/65]

They need to put in a DC coupler and then use the tap leg to modem then the out leg to feed the tv`s . and make sure it is atleast a DC-6

 

[Todd Humphrey]

A DC-6 using the through port for TV???

The issue presented here is the operation of the modem, not the image quality on the TV.

That would drop the signal level of the cable modem by 6db and the through port still looses 1-2 db at that tap value. A two way splitter drops BOTH signal levels by 3db, which doubles the signal level to the modem over using the DC method, and only drops the TV part by 1-2 additional db's. Unless your TV signal is below -5 to 0db, no television is going to notice a 1-2db drop whereas the modem may care about a 6db drop.

If you use a DC, then I suggest using the tap port for the TV and the through port for the modem.

 

[stevo/65]

Thats right , use tap to tv
It has been many years.... since i have messed with cable

 

[webbydude]

Stevo is exactly right. Signal strength is not the only requirement for a cable modem. Most modems recommend no more than 2 dB of signal to operate properly. Usually around here, Adelphia, Comcast, and Time Warner use DC6 and DC9s, with the throughput going to the television (or splitters)

The problem with an amplifier is that it not only amplifies the good signal, but whatever possible noise problems that may or may not be present.

I'm inclined to go with Rcdallas' idea and start with the drop (it should be at least RG-7 or RG-11 for runs over 100 - 150') as well as checking out the tap.

 

[stevo/65]

Stevo is exactly right. Signal strength is not the only requirement for a cable modem. Most modems recommend no more than 2 dB of signal to operate properly. Usually around here, Adelphia, Comcast, and Time Warner use DC6 and DC9s, with the throughput going to the television (or splitters)

The problem with an amplifier is that it not only amplifies the good signal, but whatever possible noise problems that may or may not be present.

I'm inclined to go with Rcdallas' idea and start with the drop (it should be at least RG-7 or RG-11 for runs over 100 - 150') as well as checking out the tap.

Thanks Webbydude,
It has been a long time since i have installed modems for cable.
I remembered something about too much db going to the modem was not good.
The company i contracted for was with Cox and they used DC-6

 

[webbydude]

Thanks Webbydude,
It has been a long time since i have installed modems for cable.
I remembered something about too much db going to the modem was not good.
The company i contracted for was with Cox and they used DC-6

It's been 5 years for me as well. Like most installers, I contracted out. Not enough $$/hour as a direct employee. Saw that many of my peers were making more money installing satellite systems; decided it was better in the long run to jump ship and go that direction. Not to mention the hours are a lot better

 

[frntchr]

Thanks all for your input!!

 

[Todd Humphrey]

webbydude, The problem presented was corrected when the splitter was removed thus increasing the signal. If the problem was not solved by removing the splitter, then your suggestion of over driving would make sense.

In this case the solution seemed to be to INCREASE the signal level, which would be the case if a DC was used and the through port feed the cable modem.

 

[stevo/65]

webbydude, The problem presented was corrected when the splitter was removed thus increasing the signal. If the problem was not solved by removing the splitter, then your suggestion of over driving would make sense.

In this case the solution seemed to be to INCREASE the signal level, which would be the case if a DC was used and the through port feed the cable modem.

The correct way to install is tap to modem
when using Directional couplers as splitters for cable modem installation.
I talked to an old cable buddy who i use to work with " many years ago"
he said the exact same thing webbydude said.
Like i said before it has been awhile since i have installed for a cable company.
I too was a inhouse tech for a cable co. before i went into contracting "more money"
I take it that you have installed for a cable company too before you started installing for satellite companies?

 

[webbydude]

The correct way to install is tap to modem
when using Directional couplers as splitters for cable modem installation.
I talked to an old cable buddy who i use to work with " many years ago"
he said the exact same thing webbydude said.
Like i said before it has been awhile since i have installed for a cable company.
I too was a inhouse tech for a cable co. before i went into contracting "more money"
I take it that you have installed for a cable company too before you started installing for satellite companies?

I never worked "inhouse". Have always been a contractor. The $$ was never appealing enough. Granted, there were benefits (401K, medical, dental, etc...) but said benefits weren't enough to offset the reduced pay.

 

[stevo/65]

I never worked "inhouse". Have always been a contractor. The $$ was never appealing enough. Granted, there were benefits (401K, medical, dental, etc...) but said benefits weren't enough to offset the reduced pay.

I was fortunate enough to get my training and experience as a "inhouse" tech first.
Was inhouse for 6 years, did all the NCTI courses available ect.
I was into it big time, then i realized with all the training and knowledge i have, it was more feasable for me to make much more money contracting. Been contracting ever since, now have been doing this stuff going on 18 years now with time as a inhouse and contractor.
But with all the pay reductions in the sub-contractors arena, i am now a retailer.
It is the the only way "IMO" to make a decent living in the satellite biz without having to work for free

 

[cableman265]

If you give me your MAC address I can look up your signal levels and possibly tell you whats going on. Or else you can get into it yourself and post it here.

 

[Todd Humphrey]

Webbydude - You are not looking that the problem presented to you in this thread. The poster said he was able to get the modem to work if he REMOVED the splitter, thus INCREASING the signal level to the modem. If he installes a DC with the TAP port connected to the modem, that REDUCES the signal level MORE than the splitter.
I am not disputing your training that a tap should be used with a modem because overdriving may be an issue, but you just cannot blindly ignore the facts presented. If the fact that increasing the signal level solves the modem problem is true, then you cannot recommend an action that LOWERS the signal more.

How does that make sense?

Do you know what a DC is, other than you are suppose to use one for cable modem installs?

http://www.dbsinstall.com/diy/parts/directionalcouplers.asp

 

[webbydude]

Stevo is exactly right. Signal strength is not the only requirement for a cable modem. Most modems recommend no more than 2 dB of signal to operate properly. Usually around here, Adelphia, Comcast, and Time Warner use DC6 and DC9s, with the throughput going to the television (or splitters)

The problem with an amplifier is that it not only amplifies the good signal, but whatever possible noise problems that may or may not be present.

I'm inclined to go with Rcdallas' idea and start with the drop (it should be at least RG-7 or RG-11 for runs over 100 - 150') as well as checking out the tap.

Webbydude - You are not looking that the problem presented to you in this thread. The poster said he was able to get the modem to work if he REMOVED the splitter, thus INCREASING the signal level to the modem. If he installes a DC with the TAP port connected to the modem, that REDUCES the signal level MORE than the splitter.
I am not disputing your training that a tap should be used with a modem because overdriving may be an issue, but you just cannot blindly ignore the facts presented. If the fact that increasing the signal level solves the modem problem is true, then you cannot recommend an action that LOWERS the signal more.

How does that make sense?

Do you know what a DC is, other than you are suppose to use one for cable modem installs?

http://www.dbsinstall.com/diy/parts/directionalcouplers.asp

Actually, WHAT I said was that I believe the drop is the 1st place you should start with. I've installed more than enough cable modems over the years to know that you can overdrive a modem. The OP may have temporarily "fixed" the modem by bypassing his splitter (which it being bad is another possibility...but that still doesn't change the fact I would still START with the drop or tap).

Regardless, there is no reason why you shouldn't use a DC (6 or 9) splitter. It's only going to drop the dB's down 6 or 9, but still keep the other levels for your video outlets.

 

[Todd Humphrey]

I must apologize, it was stevo that said the tap to modem was the correct way, and it was he that I should have directed my comments too. Sorry about that.