# Wondering If Amplifier or Directional Coupler Will Help



## Bird Doo Head (Dec 8, 2010)

Hi All!

At our house, we have Cable TV, Internet & Cable Telephone.

We have many outlets for TV, but only 4 televisions. Only 2 are ever on at one time. Three are CRT with digital adapters from the cable company. (The other one is a modern one that lets the cable plug directly into it.) We don't have any set top boxes or DVRs or VCRS.

There is a drawing attached of our cable outlet.

THE PROBLEM-
The outlet in the drawing labeled "2nd Floor Front Room West Wall" has poor signals. It is manifested by pixelating pictures or the "No Signal" error. The problem is sometimes only a on few channels & other times up to all channels. I believe evenings are worst. 

This TV is the modern one where you plug the cable directly into the TV. (i verified the TV is OK by moving it to another jack. It worked fine.) I checked the cable up to that room in the only way I have means to check- I rang it out with an ohm meter on both the conductor and the shield, comparing the result with a similar length cable hooked to nothing.

This lead me to conclude that all the splitters are simply removing too much dB gain from the cable company's amp. (It is 15 dB)

PERHAPS A SOLUTION?-
To improve the signal, I was wondering if replacing one of the splitters with a Directional Coupler (aka Tap) would be the best plan. I'd use the line that comes off the existing splitter as kind of a 'backbone' wire to feed the next set of splitters.


I got the idea from when I was an electrician at a NFL stadium and we had to run cable wires. The TV people would hand us those taps to use and we'd install splitters only at the end of the run. 
_For Example- Perhaps we would run cable to a large section of suites. Every 4 suites, we would put a directional coupler. The Tap port would continue to the next section. The other port would go to a 4-port splitter, feeding the local TV sets. (All CRT in those days) We would repeat with another tap at the next section._

I'd rather not use an amplifier since that will be one more thing using electricity.
But if it is the better plan- that's what I'll do.

THE QUESTION-
Assuming a directional coupler is appropriate..
My puzzlement is what value of Directional Coupler would be appropriate. 
I searched the internet with no success, so I'm hoping to learn something new here.

Thanks For Your Advice!
Paul


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## adamz (May 13, 2018)

How many outlets after the 7db splitter have TV sets?

The 7db splitter is the best place to start troubleshooting.


How does the TV named Liv Room South Door look? If that one is good, connect the 2nd floor Frt Room West Wall connection at the the 7db splitter to the port named Liv Room and denote the result. This "port swap" will give you an indication how good the signal is at the input of the the 7db splitter and will help determine if the signal is weak at that point or you might have an isolated issue issue on the West Wall feed.


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## Bird Doo Head (Dec 8, 2010)

Hi Adam Z
Thank You for taking time to reply & help with this question!

After the 7 bD splitter, there are 2 televisions connected. Of those, sometimes both can be the ones that are on at the same time. The other outlets have terminating resistor caps on the F-connectors.

Liv Rm South / Door TV looks good. It is a CRT TV with a digital converter box from the cable company.

I tried your excellent suggestion about swapping cables with the 2nd floor front room. The TV in the 2nd floor had the same symptoms as before the swap. The Liv Room South Door still looked good & had its channels.

Interestingly, last evening the outlet labeled "2nd Floor Front Room Stair Wall" (way upstream from the 7 dB) had several pixelating channels. This morning, it is clear & goos. That one is a "modern" TV that doesn't need a converter box.

What should my next step be? 

Thanks Again! I appreciate your help and diagnostic assistance.

Enjoy Today!
Paul


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## adamz (May 13, 2018)

If the 2nd floor TV had the same symptoms on the good port, there is most likely an isolated issue with that feed.


A possible next step is bring the TV to 7db splitter port along with a jumper cable to reach the 7db splitter. If it looks good there, then the problem is in the line that goes to the 2nd floor.



Have you tried a new wall jumper at the bad TV? 



Check all the connectors in the feed including the ones behind the wall plate. Twist-on connectors can be problems. Bad crimps can be problems. Look closely at the stinger portions (the center conductor) of the connectors with a flashlight if possible. Stinger needs to be long enough and no ground shorting the stinger to the silver portion of the connector.


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## u3b3rg33k (Jul 17, 2018)

i've designed and upgraded/replaced cable TV systems in stadiums. when they want to go from 1 tv per suite to 4, it's not as simple as "add another splitter". 

can you look in the TV and get the signal level for each drop, at the splitter, and feeding the splitter? 
btw most splitters are 3.5dB. if you have 3 tap splitter you actually have 2x 2 3.5dB splitters in one housing - that's why two are labelled 7dB and one is labelled 3.5dB. 


what grade cabling do you have indoors? any hidden splitters? those are often trouble. I usually use RG6 quad, and a single splitter indoors with as many taps as needed to home run each TV. 

putting in an amplifier without knowing signal levels can do more harm than good. if you feed any amplifier (even a good one) with too much signal, or you run it too hot, you'll just bump the noise floor and not actually get things to work better. often getting the last 3dB out of an amp doubles or triples the noise. Feeding a TV with too much signal can cause the same problem.


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## Bird Doo Head (Dec 8, 2010)

Thank You agign guys for helping!



adamz said:


> A possible next step is bring the TV to 7db splitter port along with a jumper cable to reach the 7db splitter. If it looks good there, then the problem is in the line that goes to the 2nd floor.
> I tried this good diagnostic idea. The signal was poor even with a short jumper. And, being the dope I can be, I forgot that there are two cables going up to that room. (We used to have Comcast that required two cables.) The spare cable was just as poor.
> 
> Have you tried a new wall jumper at the bad TV?
> ...


I check & did find one loose connector at the wall plate, so for diagnostics I removed the wall plate & went from cable to TV. Again, no luck.


The cables are all RG-6. Perhaps it is time to get a signal strength meter & go from there?

What I Tried Yesterday-
At the first set of splitters, the 2nd floor stair wall passed through the 5.5 and the 3.5 splitter. I moved it to the 5.5 & moved the kitchen to the 5.5 + 3.5. (It is a much shorter run at 8 feet versus 30 feet to the stair wall.) That seems to have solved the stair wall problem. The signal is good & all channels work.

Is This A Good Idea?
Instead of putting an amp. and possibly causing more problems, as ub3rg33k mentioned, what if I take out the 5.5 and 3.5 splitter and put in a Zero Loss Splitter. I'd then take the 2nd floor west wall cable all the way to it, getting it out of the 7 dB splitter.

This way, I'm not amplifying the signal but am (i think) eliminating 7 dB of loss.

Do those items work and do you thing it will be a good plan for this problem?
I realize they use electricity, but if it has to be so...


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## u3b3rg33k (Jul 17, 2018)

What's a zero loss splitter? afaik you can't divide x/2 and get x. 

i counted 8 taps on you drawing. I recommend you get an 8 way splitter like this:
https://multicomstore.com/scvs-8.ht...g0asscYiNUXK63hPCDBeT1oun8wIE4shoC3GkQAvD_BwE
feed your cable modem off a 2 way 3.5dB , put a decent amp in front of the 8 way. you should be golden.


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## Bird Doo Head (Dec 8, 2010)

I might be calling Zero Loss Splitter by the wrong name, or a colloquial name. 
It's a powered splitter that puts the signal back to the dB level is was when entering the device. I suppose it is an amplifier that doesn't amplify beyond the entry level of the signal. An example is: Electroline EDA-UG2802.

Thanks for the link to the 8-way splitter. I'm a little confused. Should the amplifier go ahead of the first pair of splitters (a 5.5 & 3.5) or the 7 dB splitter?

Thanks!
Paul


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## u3b3rg33k (Jul 17, 2018)

Bird Doo Head said:


> I might be calling Zero Loss Splitter by the wrong name, or a colloquial name.
> It's a powered splitter that puts the signal back to the dB level is was when entering the device. I suppose it is an amplifier that doesn't amplify beyond the entry level of the signal. An example is: Electroline EDA-UG2802.
> 
> Thanks for the link to the 8-way splitter. I'm a little confused. Should the amplifier go ahead of the first pair of splitters (a 5.5 & 3.5) or the 7 dB splitter?
> ...


I highly recommend you keep the cable modem before the amplifier. most cheap (i.e. home grade) amplifiers do not have a return path for the cable modem's output, so you will have very poor/no internet if you place it after the amplifier. 

honestly, i would try a single 8 way without an amp first, just to see if it works. if you can avoid the amplifier, avoid it. it probably won't, but it's worth a shot.


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## adamz (May 13, 2018)

You have conflicting items:


Item 1) I tried your excellent suggestion about swapping cables with the 2nd floor front room. The TV in the 2nd floor had the same symptoms as before the swap. The Liv Room South Door still looked good & had its channels.

*The item above indicates the port that feeds the bad TV is a GOOD port*

Item 2) A possible next step is bring the TV to 7db splitter port along with a jumper cable to reach the 7db splitter. If it looks good there, then the problem is in the line that goes to the 2nd floor. 
I tried this good diagnostic idea. The signal was poor even with a short jumper. And, being the dope I can be, I forgot that there are two cables going up to that room. (We used to have Comcast that required two cables.) The spare cable was just as poor. *
*
*Item 2 indicates the port that feeds the bad TV is BAD port. This is opposite of Item 1 above (unless the TV itself is bad, but I thought that the TV was tested and was good).**
*
Please don't over think the issue, solve the conflict above and you will have the problem identified. Other TV sets fed from that 7db splitter are good. This seems to indicate there is plenty of signal at the input of the 7db splitter. 

If you bring the TV to the 7db splitter again, try it on the other ports too. Then put it on the bad port again. Sometimes a revisit is necessary to confirm things.

Can you post a photo of the "7db" splitter? :smile:


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## Bird Doo Head (Dec 8, 2010)

Thanks for answering guys!

While the TV was in its 2nd floor location I tried moving the 2nd floor west cable to the other ports on the 7 dB splitter & got the same poor results at the TV.

I re-tested with the TV at the splitter & a new short jumper. On each port, it still had a bad signal. 

Next, I had a spare 7 dB splitter & swapped it. All symptoms remained the same. (Photo attached)

Next, I made a cable to reach from the wire for the 2nd floor west wall wire (near the 7 dB) and connected it to the 5 dB splitter that is upstream. (Connecting the up-the-wall cable to the new cable with a F-Coupler). 
I put the TV back in the room & it worked perfectly. So, I believe this means the cable up the wall is good.

I wonder if these tests, and the ones you guys taught me, mean that there is good signal up to the 7 dB and the 7 dB, plus the extra cable-feet up the wall, weakens the signal just enough to cause problems. (Just my amateur's guess)


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## adamz (May 13, 2018)

Nice job checking things again.



I re-tested with the TV at the splitter & a new short jumper. On each port, it still had a bad signal. The TV doesn't work at the splitter. So it can't be connected to this splitter. The bad TV simply cannot overcome the 7db loss even though the other TVs are good on the 7DB splitter (which by the way the 7DB splitter is called a 4-way splitter).


*You have several choices to try:*


1. You can try keeping the bad TV on or near the 5db splitter since it works there. Then I assume you will have gained a TV with no signal - put the dislocated TV on the 7DB splitter where the bad TV was. Advantage of this choice is it's no cost.

2. Get a higher gain amplifier to replace the 15db gain, perhaps a 25db gain amp 54-900MHZ bandwidth. I don't think it will hurt replacing the 15db amp as opposed to adding a 2nd amp.

3. Get a single inline amp +7db minimum just for the bad TV. No relocating feeds with this choice.

4. I think when you say zero loss splitter, you actually mean a powered splitter that might even boost the signal. If you go this route, simply replace the 7DB splitter with a powered splitter similar to this: https://www.amazon.com/dp/B00695G11...9a4a-409119324e83&ie=UTF8&qid=1533061542&sr=2


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## Bird Doo Head (Dec 8, 2010)

Thanks for the list of things to try, Adam. I apologize for my delayed reply while I tested some things.

I _think_ my results from trying your Step One (Relocating) told me that the tuner in the TV isn't a terribly good one. I put one of our CRT TV sets that we use with a digital adapter from the cable company where the problem TV is (2nd floor west wall- after the 7 dB). It got a fine signal and all of the channels.

Since "she who gets two votes" would prefer to have the CRT TV where she watches, I'll put things back where they were and probably use either an inline amp or replace the existing 15 dB amplifier with a higher gain, per your suggestions. 

I think I understand what I read that if the new amplifier causes problems I can put an attenuator on the troublesome circuit.

Thank You Both again for your help. I certainly appreciate the education I got from you guys and will report back what my results are.
Enjoy Today!
Paul


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## adamz (May 13, 2018)

Good luck with your choice.



There are other options. You can put a cable tuner on the problem TV. It might increase the cable bill though, but is a simple fix. Even a new TV seems like it might fix it.


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## adamz (May 13, 2018)

Just an idea - If you put a cable tuner on the problem TV try to use of its AV inputs instead of the tuner input if it's possible.


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## Bird Doo Head (Dec 8, 2010)

Thanks for the idea of using AV inputs. I think I'll experiment with the other solutions you guys presented (amplifier, etc.) and if necessary get a new TV (or a book and reading glasses).
Thanks Again!
Paul


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