cable amplifier?

[huffmuds9320]

I have digital cable tv in my house which the cable company provides the cable box. The tvs with the cable box has digital cable while the other tvs that don't have the cable box can watch the analog cable channels of course.

Here is how my wiring is setup, I'll try to describe it as best I can. The main cable comes into the house and is connected to a 2 way splitter. From the splitter one cable goes to the living room upstairs (~25 feet). The other one goes to the back of the house (~80 feet) which is then connected to a 3 way splitter. From the 3 way splitter another cable (~25 feet) goes the the rooms upstairs and finally a 2 way splitter so both tvs upstairs. The tv in the living room has no reception problem since it is closest to the source. The tvs in toward the back of the house that have analog cable has a bit of snowing images on some channels. And the tv with digital on some channels either cannot receive or appears skipping.

The cable splitters say 5-900mhz on them. I am using the RG-6 quad shield cables, my old wiring was RG-59 which I replaced because the wiring was very old. With the new RG-6 wiring it improved the reception a bit.

The questions I have are if the 2.4ghz splitters are better than the 900mhz splitters, I though you only needed the 2.4ghz if you have satellite tv. And my other question is if an amplifier would improve the reception. Thank you.

 

[brianl703]

The three-way splitter has 3 outputs. One is labeled 3.5dB and the other two are labeled 7dB.

The one that is labeled 3.5dB has the strongest output and should be the one connected to the TVs in the back of the house.

Also, if any of these splitters have unused outputs, you should replace them with either an F81 barrel or a 2-way as appropriate.

I've heard that 2.4GHz splitters don't work well for cable, I've never used them so I can't say for sure. I just use the 1GHz splitters and so do the cable companies. You can often get splitters from your cable company's bill payment office or you can go to Lowe's or Home Depot and get the Ideal 1GHz splitters. These Ideal splitters are at least as good as the ones the cable company uses.

 

[JHZR2]

There is such a thing as too much amplification. Garbage in will equal garbage out, and this is the case for your signal distribution as well as your TV.

Do you have reason to believe that the signal is loosing adequate strength to display fully/properly?

 

[brianl703]

Well, depending on how his splitters are wired, he could have as much as 14dB (3.5 + 7 + 3.5) of splitter loss to the furthest TV.

A 16-way splitter has 14dB of splitter loss, to give you an idea.

How many actual TVs do you have connected? I bet it's a lot less than 16, which means that this problem could be fixed without using an amp, simply by redoing how the splitters are wired.

(EDIT: I mistakenly posted that an 8-way splitter has 14dB of loss..nope..it's a 16-way..)

 

[brianl703]

From what I gather your wiring is arranged as follows:

2-way splitter #1:

Input < Main feed from cable co.
Output #1 > Living room TV
Output #2 > Three-way splitter #2

3-way splitter #2:

Input < Output #2 from 2-way splitter #1
Output #1 > To 2-way splitter #3 upstairs
Output #2 > What?
Output #3 > What?

2-way splitter #3:
Input < Output #1 from 3-way splitter #2
Output #1 > To TV
Output #2 > To TV


What is connected to the other 2 outputs from the 3 way splitter? If nothing, that splitter should be removed and replaced with an F81 splice. That will improve the signal.

 

[huffmuds9320]

Yes that is how my wiring is arranged.

The 2 other outputs on the 3 way splitter are connected to 2 tvs. On the 3 way splitter it says 5-900mhz but it does not say how much signal loss for the output. From my observation the tvs that all connect to this 3 way splitter have some reception issues.

 

[brianl703]

Try replacing the 3-way splitter with a 1GHz one, and connect the 3.5dB output to the 2-way splitter that feeds the other TVs. That will get your max splitter loss down to approx 11dB which will probably be OK.

It sounds like the 3-way splitter in question is just a piece of [censored], especially if it doesn't even tell you what the loss is. I bet if you pushed on the backplate with your pinky it would bend and crush in. Is it by chance gold plated?

This is a good splitter:

Note the lack of gold plating and the fact that it does tell you what the loss on each output is.

 

[brianl703]

Another good splitter.

 

[brianl703]

BTW, the .5dB difference between these splitters in the loss is simply a result of how they calculated it.

 

[Win]

Originally Posted By: brianl703
Well, depending on how his splitters are wired, he could have as much as 14dB (3.5 + 7 + 3.5) of splitter loss to the furthest TV.


I figured at least -9 dB to - 12 dB, plus cable loss that will increase with frequency.

This is a lot of attenuation and has the same practical effect of introducing an equivalent amount of noise into the system.

Might want to have the cable company check the signal strength to make sure its not noisy to start with, and then put a good quality (low noise) amplifier right after the first splitter, so the nearest TV does not have AGC problems.

All of the consumer grade splitters are likely little better than junk.

 

[brianl703]

The only ones I've found at retail that are any good are the Ideal ones. I don't buy splitters anymore since the Comcast office is just up the street...

BTW, both my eMTA and my cable modem are working fine with 11.5dB of splitter loss..but the signal off the tap is pretty high to begin with.

 

[huffmuds9320]

Originally Posted By: brianl703
Try replacing the 3-way splitter with a 1GHz one, and connect the 3.5dB output to the 2-way splitter that feeds the other TVs. That will get your max splitter loss down to approx 11dB which will probably be OK.

It sounds like the 3-way splitter in question is just a piece of [censored], especially if it doesn't even tell you what the loss is. I bet if you pushed on the backplate with your pinky it would bend and crush in. Is it by chance gold plated?

This is a good splitter:

Note the lack of gold plating and the fact that it does tell you what the loss on each output is.




Thanks for the replies everyone.

Yeah the 3 way splitter I have is gold plated, I used to think that gold was better quality. I noticed that on the 2.4ghz splitters it says "power pass" on them and does not list the signal loss numbers on them.

A while back I called up my cable company (Comcast) and they ran some checks on the line. They said everything looks to be okay and told me to check the connections. I even went and exchanged the cable box because the one they gave me the first time was bulky and looked old.