# Multiple coax signal amplifiers?



## JonCiccarone (Jan 10, 2016)

Also, forgot to mention, in the living room, before the coax connects to the TV, it connects to the power strip that the whole entertainment system is plugged into, and there's a coax cable connecting the power strip to the TV (tried to upload a picture but I'm finding it impossible to do so from a phone). This has been like this forever so I chose not to touch it when I made the transition. Not sure if this is helping my signal strength in the living room, I figured it was just surge protection, but I thought it was worth sharing.

JC


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## diyorpay (Sep 21, 2010)

I would think all 42 channels would get to all tvs.

Make sure bedroom channel scan is set to antenna and not cable.


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## FrodoOne (Mar 4, 2016)

Firstly, there is no such thing as a HD antenna.
A TV antenna can range from a simple di-pole (or folded di-pole) up to one with many other “elements”, which will give it higher “gain” (at the frequency range for which it is designed).
The antenna which you now have “goes into an amplifier and is then split 6 different ways”.
You mention ”I can get 42 channels in my living room, but only 16 in the master bedroom”. However, you do not state what channels are “received” at the other four locations fed by these “splitters” nor how the splitting is arranged.
As diyorpay said:-


diyorpay said:


> I would think all 42 channels would get to all tvs.
> Make sure bedroom channel scan is set to antenna and not cable.


“Will adding another (or multiple) coax amplifiers fix my problem?”

Unlikely, in fact it is almost certain to make things worse.
With digital TV, the TV tuner is designed to operate using the signal received in a “normal” service area by a reasonably good antenna. If operated in a “fringe” area where the signal is “weak”, where with an “analogue” TV you may have received a “snowy” picture, with “digital” TV the picture will “break up” and/or not be “received” at all. (This is called “The Digital Cliff”)
Conversely, if close to a transmitter where the signal is strong, or too much amplification is applied to the received signal, the digital TV tuner will be “overloaded” and again the picture will “break up” and/or not be “received” at all. (With commercially available amplifiers, this excess signal will not be such that it will destroy the tuner.)

Because you have the signals you need in one place
make sure that the TV(s) concerned ARE set to scan and receive the required channel frequencies (and coding) AND
check the organisation and wiring of the splitters concerned.

If you have (or can borrow) a small digital TV which will receive all channels AND has a setting which will give an indication of the “Strength” and “Quality” of each channel, plug it into each co-axial outlet in turn to check that the signals are available at a reasonable strength and quality at each point.
If so, any problem lies with the TV normally plugged in at that point.
If not, any problem lies in the splitters and their connections.


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## FrodoOne (Mar 4, 2016)

JonCiccarone said:


> Also, forgot to mention, in the living room, before the coax connects to the TV, it connects to the power strip that the whole entertainment system is plugged into, and there's a coax cable connecting the power strip to the TV (tried to upload a picture but I'm finding it impossible to do so from a phone). This has been like this forever so I chose not to touch it when I made the transition. Not sure if this is helping my signal strength in the living room, I figured it was just surge protection, but I thought it was worth sharing.
> 
> JC


This "arrangement" is an attempt to ground the antenna via the "ground" wire in the socket outlet supplying the power strip - and is NOT a good idea.

Search on "Grounding TV Antenna", to see what should be done.


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## JonCiccarone (Jan 10, 2016)

FrodoOne said:


> If you have (or can borrow) a small digital TV which will receive all channels AND has a setting which will give an indication of the “Strength” and “Quality” of each channel, plug it into each co-axial outlet in turn to check that the signals are available at a reasonable strength and quality at each point.
> If so, any problem lies with the TV normally plugged in at that point.
> If not, any problem lies in the splitters and their connections.


Ok I'll do that when I get the chance. So you don't think the length of the coax runs has anything to do with the lack of channels in the bedrooms? I've read about signal loss over long runs, but again, I'm not sure if that's relevant to my situation.

Also, I noticed today that the bedrooms have RG59 cable instead of RG6 like the majority of the house, could this have anything to do with having less channels?
Thanks 
JC


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## FrodoOne (Mar 4, 2016)

JonCiccarone said:


> My setup is the antenna cable goes from the roof, thru the attic, all the way down to the basement (guessing about a 30-35 ft. run) where it goes into an amplifier and is then split 6 different ways. The living room is significantly closer to the splitter than the master bedroom,





JonCiccarone said:


> Ok I'll do that when I get the chance. So you don't think the length of the coax runs has anything to do with the lack of channels in the bedrooms? I've read about signal loss over long runs, but again, I'm not sure if that's relevant to my situation.
> 
> Also, I noticed today that the bedrooms have RG59 cable instead of RG6 like the majority of the house, could this have anything to do with having less channels?
> Thanks
> JC


At no point in this discussion have you indicated that you have tested just how well a single known working TV will work when connected directly to the antenna – without any amplifier or splitters involved. (You really should make this test and [hopefully] the TV concerned will be able to provide some indication of the “strength” and “quality” of the signal which it is receiving – on the various “channels” concerned.)
You have only quoted the length of the co-ax run from the antenna to the amplifier/splitter (guessing about a 30-35 ft. run) – 10 m.
The “majority’ of the house is in RG6 but the “bedrooms” are in RG59, and you have not indicated any lengths involved.
You have not indicated the frequency of the TV “channels” which you need to receive but US UHF TV Channels 14 to 51 range from (about) 470 MHz to 697 MHz.
The centre of this range is about 600 MHz and 
http://www.net-comber.com/cable-loss.html indicates that (at this frequency) the “loss” over 10m (33’) of RG59 is 2.03db and for RG6 it is 1.63db – which is difference of only 0.4db and (hence) NOT significant.
You have not indicated the “gain” of the amplifier being used but typical amplifiers available in this country have “gains” of around 15 db, so, presumably, yours would be similar.

When you “split” any output signal from an amplifier “in two”, the “loss” for each output is 3.1db.
So, if you were to take an input signal and from an antenna,
amplify it by 15db,
“split” the output 3 times (to derive 8 outputs), the result would be 
a “gain” of 15db –(3.1*3)
= 15db-9.3db
= 5.7db (“Gain”) on each of the 8 outputs involved.
(Note that your outputs are split [only] 6 ways, so that one or more of these may have less “loss” than this. However, it is not possible to determine this without knowing how the “splitting” is “arranged”.)

From this you would need to subtract any losses in the co-ax cables.
However, since you know that one TV close to the amplifier and splitter(s) is working satisfactorily and the worst you can expect from the “loss” in any existing cable in your premises is 2.03 for each 10 m (33’), I think that you may rule out co-ax cable losses as a problem – unless you have a house with cable runs of well over 30 m (100’).


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## JonCiccarone (Jan 10, 2016)

Hi Frodo, thanks for your replies.

I haven't tested the signal strength and to be honest I'm not very familiar with how to do so. I'm certainly capable of connecting the antenna cable directly to the living room cable, but I'm not familiar with how to test signal strength.

I did some more tests yesterday and got more details, the only coax run in the house that is RG59 is the master bedroom. I'm assuming the other 2 bedrooms were wired at a later date. The cable connecting the master bedroom tv to the wall jack was also RG59, and out of curiosity I swapped it out for an RG6 quad shield cable, and I was able to get 21 channels versus 17 just from doing that. The other bedrooms (wired with RG6) can retrieve around 31-34 channels, but the picture quality isn't the best, gets pixelly at frequently. The master bedroom is about 45 feet from coax splitter, and the other 2 bedrooms are about 30 ft. Please let me know how I can get you the information you need to "diagnose" the potential problem. Thanks

JC

PS - here's a link to the coax setup https://docs.google.com/document/d/1-kx7HY6GkkLVvME3rrLMTTQscvoNDlI94X4S_43GnqY
Antenna cable is the far right one going into amplifier. White cable is cable company connected directly to cable that goes to modem for Internet


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## GrayHair (Apr 9, 2015)

Look at the ouput ports on the CATV splitter. Some ports may have higher attenuation than others. Put your "problem" set on the port with least attenuation and then direct tune to a "missing" channel. If your set won't tune to a channel not in it's table, you'll have to rescan.

Just for grins, pick up a type-F barrel connector (should be cheap!) and connect the source cable directly to the cable for the problem set. Could be a flaky splitter.

And after all that, some sets just have better receivers than others. Once transmission line problems have been resolved or eliminated, check the signal level (often through the set's menu) on both sets at about the same time. Some menus and instruction manuals present information in "unusual" ways or headings. Go exploring and GOOD LUCK!


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## FrodoOne (Mar 4, 2016)

JonCiccarone said:


> Hi Frodo, thanks for your replies.
> 
> I haven't tested the signal strength and to be honest I'm not very familiar with how to do so. I'm certainly capable of connecting the antenna cable directly to the living room cable, but I'm not familiar with how to test signal strength.
> 
> ...


While I have given you the best advice that I can, I think that I should now "drop out" from any further discussion in relating to your "problems" - concerning TV reception - since I am in Australia and you are in the USA.
(The connection via your Cable Company to your Modem should have nothing to do with your TV [off air] connection.)
I am quite surprised that no person in North America has "jumped in" to "correct" anything that I have said! (Was I not wrong in any way?)

Again, I regret that I can see no way in which I can assist you further!

(I assume that you did note my earlier reference to "coding". It has been noted here that, several years ago, certain manufacturers did not include the decoding of MPEG4 in their receiving devices available at that time - but only included decoding up to MPEG2.
Since some TV transmitters are now using MPEG4 (in this country), such (obsolete ?) "receivers" will not now receive/decode these transmissions, to the frustration of those possessing them.)
The major delinquent company concerned seems to be P*******c

Is it possible that some of your receiving devices are "obsolete", as compared to the transmissions which you wish to receive?


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## ktkelly (Apr 7, 2007)

I would consider changing from your current amplifier to splitter set up, to to a one in 8 out all in one unit.


https://www.amazon.com/Channel-Mast...=8-4&keywords=cable+tv+distribution+amplifier


This will give you a more balanced set up, having equal gain on all ports which basic splitters do not..


May not correct all of your issues, but it should get you a lot closer, although the RG59 can and most likely will be a cause of additional signal loss.


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## JonCiccarone (Jan 10, 2016)

Figured I'd get back to all of you with the solution to my problem,

After a lot of frustration and confusion about not getting a good signal in the master bedroom, I decided to buy a better antenna, and out of stubbornness I chose to run a new coax cable to the master bedroom from the main splitter to replace the old RG59 that was used, as I was convinced this was causing increased signal loss. This is where I found the real problem...

Thinking that replacing the cable would be as simple as connecting some new RG6 quad shield to the old RG59 and pulling the new cable through, I tried to do just that. To my misfortune, and many holes cut in the downstairs bedroom wall, I found a number of surprises. The RG59 cable was spliced in the wall to a short distance of RG6 quad Shield, where it then connected to a hidden splitter screwed to the ceiling joist, then transitioned back to RG59. The rg59 run from the hidden splitter to the master bedroom had at least 50-60 feet of extra cable taped together in a big coil and buried behind drywall in the basement... 
So I removed this mess of a setup and rewired everything with 1 rg6 quad shield cable, and moved the hidden splitter to an accessible location.

Now I'm able to get 37 channels, which is the same as the rest of the bedrooms. Still not as much as the living room, but I'm convinced that the receiver on the living room tv is stronger as it is a much nicer tv, and also the shortest coax run in the house. Very thankful to be done with this "learning experience".

Thank you all for your help,
JC


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## FrodoOne (Mar 4, 2016)

JonCiccarone said:


> Figured I'd get back to all of you with the solution to my problem,
> ################
> Now I'm able to get 37 channels, which is the same as the rest of the bedrooms. Still not as much as the living room, but I'm convinced that the receiver on the living room tv is stronger as it is a much nicer tv, and also the shortest coax run in the house. Very thankful to be done with this "learning experience".
> 
> ...


Thank you for your information concerning the problems which you found.
It is "satisfying" when a questioner lets others know of the problems which have been found and which those attempting to answer his questions may not have imagined!

Might I suggest that you "document" the "set-up' for your own benefit and for the benefit of anyone who in the future may purchase your house.

I have attached a document (made originally using "Powerpoint") showing the lay-out of the TV distribution system in a house sold about 5 years ago.
This was left for the new owners, with other documents relating to the premises, in the hope of assisting them should they wish to make any changes.


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