Which amplified ota signal splitter do you recommend?

[sktrus]

A friend is considering dropping her satellite service off if she is able to get good ota signal on her tvs. She has been using ota with usb adapter to hopper 3. ( A new white color dual adapter).The results are good. Her antenna is amplified. What she is hoping is that the good signal reception from nearby tv towers will stay the same (or almost same) if she uses amplified signal splitter.
I remember reading here that a cheap old fashioned 3-4 way splitter (without power cord) will degrade the quality of signal when it comes to HD reception.
So, any solid splitter out there? Preferably, from Amazon. She is willing to try it and cut the cord if she is satisfied.
Thanks.

 

[TheKrell]

She probably doesn't need another amplifier at all since her antenna is amplified. But what I think she might want is called a "distribution amplifier", which amplification is different depending upon how many outlets it has. How many ways does she want to split her signal?

 

[sktrus]

Thanks TheKrell. I couldn't remember the right word 'distribution amplifier'. I think her family has 4 tvs in different rooms. I wonder if you keep the antenna cable amplified (connected to outlet) and attach the end to a distribution amplifier. So, the amplified antenna cable provides a good signal, and the distribution amplifer provides the signal to all 4 tvs without any signal loss. Am I right with my assumption here?

 

[Jim5506]

I have read anecdotally that having multiple amps can cause problems. Probably best to get a good pre-amp at the antenna and then split the signal as soon as it comes in the house.

 

[TheKrell]

I think her family has 4 tvs in different rooms. I wonder if you keep the antenna cable amplified (connected to outlet) and attach the end to a distribution amplifier. So, the amplified antenna cable provides a good signal, and the distribution amplifer provides the signal to all 4 tvs without any signal loss. Am I right with my assumption here?

I have an unamplified antenna going into my attic and to the input of a 4-way distribution amplifier. 3 of the outputs went to my dish network receivers upstairs, while the other went down 3 floors where it was split again. I used another amp (with modest amplification) in series with the other in the attic, and then split that 2 more ways.

I have read anecdotally that having multiple amps can cause problems. Probably best to get a good pre-amp at the antenna and then split the signal as soon as it comes in the house.

Yeah, I think all these amps introduce some noise, so serial amps like I reported above would be amplifying the noise. But I had no issues with them wired as described above for years. When I upgraded to the H3, I removed all amps and now that coax is going all the way from my roof antenna down to my basement with no amps whatsoever. Seems to work fine. At the same time, I went with a high gain antenna.

So, what do I conclude? It worked before, and it still works now just as well or better than it did, even with 4 major changes. The changes were:

1. Replacement of the VIP receivers with an H3 having one OTA input
2. Removal of all amps.
3. Use of the white AirTV adapter rather than the built-in tuners in the VIP receivers.
4. A better antenna.

I'm not messing with it at this point.

 

[sktrus]

Thanks guys. I must still ask few questions. Not familiar with terminology! Does 'the noise' mean poor picture quality or audio issues? Having two amplified devices (antenna and dist. amplifier) makes the situation worse?
Her cable comes from attic antenna to her basement, connected to amplifier with on /off switch. I read here at forum that amplifier gives better result if it is next to antenna. Unfortunately, that's not the case for her. How about certain brands, types to consider buying? No idea what to chose!

Amazon product ASIN B0082ZJNW6
Amazon product ASIN B001PI09SE
or something else from a reputable web site.

 

[Inclined Orbit]

There is another thread on off air antenna preamps and I would suggest reading that thread and getting the best recommended preamp and mount that at the antenna, then use a passive 4-way splitter to feed the TVs. What this does is put the first amplifier in the system right at the antenna for the best noise figure and amp will then make up for cable loss to the basement and through the splitter. Since a 4-way TV splitter has about 7dB loss an amplifier in the 15dB gain range should be fine, even for long cable runs. The amplifiers built into active splitters are not designed for low noise and a low noise preamp designed specifically to be fed directly from an antenna will provide a better quality signal.

I suspect if you simply add a 4-way divider to the existing amplifier in the basement you will probably have the same signal quality at all TVs that you have now feeding just one TV because the lowest gain antenna preamps are about 10dB gain and more than enough to make up for a 4-way splitter with a few dB left over. Moving that same amplifier to the antenna will improve signal quality simply because it will be ahead of any cable loss to the basement and the signals its amplifying will have less noise, so every signal will be slightly better.

 

[sktrus]

Thanks I Orbit. Another beginner’s question. Number of TVs being used with 4 way splitter at the same time. 4 TVs are connected. But, only 2 TVs will be used at the same time. Does that mean the video quality can’t degrade too much? ( 2 compared to 3-4 TVs). Or does it mean it won’t matter because the signal is split into 4 ways under any circumstance?

 

[Altitudinous]

Agree with Inclined Orbit, and I suggest two things, if I may:
1. While she still has Dish, while watching an OTA channel, hit Info and Recall to bring up the signal strength. Do this for all channels she cares about. If the numbers are something like 80 or above (I regularly watch and record channels that report around 70 signal strength from the Hopper 3 with AirTV dual white adapter with no pixelation, from a powered $13 antenna that is 500 feet away and towers are 60 miles away), then you've likely got enough margin to be fine with a passive 4-way splitter.
2. Go get one from Lowe's and try it for 10 bucks, such as this one...you could return it if it's not satisfactory.
IDEAL
Zinc 4-Way Coax Video Cable Splitter
Model #85-334

 

[sktrus]

Good suggestion Altitudinous. Cheaper better if it works. We will look into it. Thanks.

 

[charlesrshell]

Thanks I Orbit. Another beginner’s question. Number of TVs being used with 4 way splitter at the same time. 4 TVs are connected. But, only 2 TVs will be used at the same time. Does that mean the video quality can’t degrade too much? ( 2 compared to 3-4 TVs). Or does it mean it won’t matter because the signal is split into 4 ways under any circumstance?

Can someone answer sktrus question?

 

[sktrus]

Yeah Charles, waiting!!

 

[Altitudinous]

I believe that the answer is there is some signal drop at all of outputs of the splitter regardless of how many TVs are being used at the same time. Many splitters have the dB loss at each output written right on the label.

 

[charlesrshell]

I believe that the answer is there is some signal drop at all of outputs of the splitter regardless of how many TVs are being used at the same time. Many splitters have the dB loss at each output written right on the label.

I think you are correct.

 

[TheKrell]

I believe that the answer is there is some signal drop at all of outputs of the splitter regardless of how many TVs are being used at the same time. Many splitters have the dB loss at each output written right on the label.

I agree. These TV coaxes are transmission lines and it does not matter whether the TV is on or not. That's assuming the TV terminates the coax which it surely does. I would not try to improve matters by connecting only 2TVs to a 4-way splitter. The disconnected legs will see an infinite impedance and reflect the signal back toward the splitter. Same with a shorting plug. The proper termination of a disconnected coax is done using a 75 ohm plug.

 

[Inclined Orbit]

Thanks I Orbit. Another beginner’s question. Number of TVs being used with 4 way splitter at the same time. 4 TVs are connected. But, only 2 TVs will be used at the same time. Does that mean the video quality can’t degrade too much? ( 2 compared to 3-4 TVs). Or does it mean it won’t matter because the signal is split into 4 ways under any circumstance?

A signal splitter or power divider will have the same loss on all ports when terminated with the proper impedance or TV sets regardless if they are receiving or turned off. A TV set that is turned off still presents a reasonable load close enough to 75 ohms to an antenna or splitter in the antenna path. If you leave some ports on the splitter disconnected it will cause the loss to change very slightly due to a high VSWR and that usually results in the frequency response of the ports in use to have some amplitude ripple.

What that means in layman's terms is where a splitter with all ports terminated properly with a TV set or a 75 ohm load, a 4-way splitter will have a fairly consistent loss around 6 to 7dB across its specified frequency range. Leave a few TVs disconnected and the frequency response through the ports still in use will have slightly more loss at some frequencies and a little less loss at other frequencies that comes and goes across the entire frequency range. The additional loss can be around 1dB and the absence of loss can be up to a dB in a sinusoidal pattern across the entire frequency range.

Bottom line is always terminate any unused ports on your splitters with a 75ohm load resistor so the splitter will be working to advertised specs and not causing unpredictable performance.

 

[charlesrshell]

A signal splitter or power divider will have the same loss on all ports when terminated with the proper impedance or TV sets regardless if they are receiving or turned off. A TV set that is turned off still presents a reasonable load close enough to 75 ohms to an antenna or splitter in the antenna path. If you leave some ports on the splitter disconnected it will cause the loss to change very slightly due to a high VSWR and that usually results in the frequency response of the ports in use to have some amplitude ripple.

What that means in layman's terms is where a splitter with all ports terminated properly with a TV set or a 75 ohm load, a 4-way splitter will have a fairly consistent loss around 6 to 7dB across its specified frequency range. Leave a few TVs disconnected and the frequency response through the ports still in use will have slightly more loss at some frequencies and a little less loss at other frequencies that comes and goes across the entire frequency range. The additional loss can be around 1dB and the absence of loss can be up to a dB in a sinusoidal pattern across the entire frequency range.

Bottom line is always terminate any unused ports on your splitters with a 75ohm load resistor so the splitter will be working to advertised specs and not causing unpredictable performance.

Thanks Inclined Orbit. Good info.

 

[Jim5506]

A four way splitter will result in each out put having approximately 1/4 of the signal strength of the input, or -7dB.

Electricity can be loosely compared to water flow, if you have a hose outputting 40 gallons per minute and you attach it to a 4 way output manifold you get approximately 10 gallons per minute out of each of the four attached output hoses.

Signal strength is measured in decibels (dB) which is a logarithmic measurement where doubling the associated number reflects the square of the value not the doubling. It is a multiplication of the value by itself instead of the addition of the value to itself.

If you are getting an acceptable signal at one TV, splitting the signal 4 ways would mean that you would only need to amplify the signal 7 -8 dB to approximate the original signal strength at the output that was present at the input.

So with a satisfactory input signal, you only need a 7 -8 dB amplifier to fix your problem. You will note the two amplifiers shown in post #6 above are well within that range.

You don't need to over amplify the signal, if it is satisfactory for all channels when connected directly to one TV, then the 7.5-8 dB distribution amps will work fine.

 

[sam_gordon]

No one has pointed out yet that splitting the signal (generally) will NOT affect video or audio quality. You won't lose quality until you lose ENOUGH quantity of signal. This is the "digital cliff". On a scale of 1-10, a signal strength of 4 should give you the identical picture that you get a with a signal strength of 10. It's only when you get down to 1 (maybe 2) that you see a difference. These numbers are made up, I'm not saying that if you have only 20% of signal, that your picture will go to crap.

Does your friend need a distribution amp or will a four way splitter work? No one here can say for sure. How much signal is coming into the antenna? What kind of cable to she have going to the TVs? How long are the runs between the antenna and the TVs?

I have found my TVs do a better job picking up antenna signals than my Dish receivers.

Me being the cheap bastard that I am, I would hook up the four way splitter, then do a channel scan on the TVs. If I start having picture quality issues or don't get all the stations I think I should, then I would add an RF amp before the splitter. As pointed out, you'd need about a 25-30 db amp to make up for a four way split (4x7=28).

 

[Jim5506]

It's not 4X7!! You only need enough ot get you above the digital cliff. The 7dB is the total loss in the splitter, the 4 is built into the 7dB. Companies use a 30dB amplifier to make up for line losses plus splitting.

IF your noise floor is low and you use a low noise pre-amp, a 30dB pre-amp can bring the usable signal up for very weak stations, but the caveat for amplifying is that amplifiers amplify the noise floor plus they add whatever noise is in the amplifier itself and usually end up narrowing the difference between usable signal and the noise in the signal.

ONLY use a 30dB pre-amp in deep fringe situations, if you have a moderately strong station nearby, slapping a 30 dB pre-amp can overload you tuner and really mess things up.

One last comment. Digital TV reception is part science (the numbers) and part art (trial and error). You never really know if something is going to work until you try it. TVFool may say your signal is too weak to receive but you may be able to slap a 30dB pre-amp on your antenna and the station may work. Got an idea - give it a try and see if it works for you.