# Anything bad with having 4x splitters w/ MOCA?



## hostage (Jul 27, 2004)

Are there any issues with having 4 splitters on a cable mesh mesh network with OTA and MOCA devices? I have the following:

2x Tivo Minis
2x Moca Adapters
1x Tivo Roamio
1x TV Antenna

I know splitters can weaken a signal, though I am a little confused of how it would work in a situation where the source is from more than one location. Is there any rules of thumb? I am using 5-2k+ splitters I got off of Amazon I am currently bipassing one splitter as I was having issues with signals. I don't know if this was from loss or if it was from it being a 1k splitter. I know I am not using it for it's intended purpose, though it is a little confusing lol.

Splitters Purchased:
https://www.amazon.com/Pack-Holland-Dishpro-Satellite-Diplexer/dp/B00684D77A
https://www.amazon.com/gp/product/B00KO8W9RA/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B00KO8W93E/ref=oh_aui_detailpage_o03_s01?ie=UTF8&psc=1

Most of my house is RG6 and I do have a couple of runs of older cables, I might re-crimp some of the ones that were to hard to replace.

I did try stringing a tivo mini to the out of a moca adapter that was plugged into a microcell, though it didn't work. Now I wonder if I should have had a splitter on that 0_o.


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## snerd (Jun 6, 2008)

As a rough rule of thumb, an N-way splitter sends a bit less than (1/N) of the RF signal power to each of the outputs. Splitters always absorb some of the RF power (converting it into heat), thus the qualifier "...a bit less...".

A brief RF tutorial:

MoCA networks are point-to-point, so at any specific instant in time there is only one device sending data, and one device receiving data. In a properly configured MoCA network (with PoE filter on the input of the first splitter), the signal from the sending device travels up through the coax (passing "backwards" through splitters) until it "reflects" off the PoE filter and passes down through the coax "tree" to reach all of the MoCA devices. Splitters are actually bi-directional, and the same fraction of power will pass between the input port and any specific output port, no matter which direction the RF signal is moving. So, signals passing "backwards" through a splitter will pass a bit less than (1/N) of the RF signal power through to the input port of the splitter, while absorbing most of the unpassed signal.

A splitter will pass all frequencies (up to the max frequency rating of the splitter) between the input port and each of the output ports. A diplexer is a slightly different beast, because it treats different frequencies in different ways. MoCA signals will pass mostly between the IN port and the SAT port, while frequencies used for CATV and modems will pass mostly between the IN port and the VHF/UHF port. Compared to a typical 2-way splitter, the splitter will pass about 45% of the incoming power to each output port (absorbing 10%) while a diplexer passes about 70% of incoming power. So, there is less RF power loss going through a diplexer, while different types of signals are passed to different ports.

It is OK to use multiple levels of splitters, while keeping in mind that the RF power is diluted each time a splitter is encountered. MoCA networks support up to 16 devices, so a balanced tree built from 2-way splitters could have 15 splitters using 4 levels of splitters. Ignoring losses in the coax, a MoCA signal in this kind of system would pass up through 4 levels of splitter for a total loss of about 14 dB, the signal would then reflect off the PoE filter (with another loss of 1.5 dB) and pass down through 4 levels of splitters (another 14dB loss) for a total loss of 29.5 dB. MoCA devices are designed to withstand about 51 dB of loss before data rates begin to decline, which means there is extra "headroom" of about 21dB.

Bottom line: as long as you don't go out of your way to use too many splitters, and you have a PoE filter installed, signal loss through splitters isn't usually a problem.


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## krkaufman (Nov 25, 2003)

Fool me once, shame on Tennessee ...  Never heard back from you on the previous "PoE" MoCA filter thread, here: MOCA POE filter suggestions?

We'd have to know more about specifically how your devices are connected via coax and networked to be able to determine whether TiVo Support's suggestion Re: the "PoE" MoCA filter is accurate. The brand & model to buy comes second.

Similarly, how all the splitters are used in your setup, and what's connected to each, is just as important as knowing the specs of each component. If possible, it would be useful to have a more detailed description or diagram (however rough) informing how your devices connect. See attached for a few examples, for inspiration.



















​
That said, the splitters you linked are seemingly designed for satellite setup use. (They're listed under "Satellite TV Equipment," have satellite frequency specs, and the power passing is an additional hint.) These splitters would not be ideal for a MoCA setup, since, being designed for satellite, they would have higher output port isolation at MoCA frequencies (1125-1675 MHz, within the satellite frequency range) .... rather than intentionally lower output port isolation, as found in the Holland GHS-PRO-M (e.g.) and Verizon MoCA 2.0-rated splitters.

'gist: The frequency spec on a splitter isn't determinant regarding its relative suitability for a MoCA setup.

The components linked may work, but the cumulative difference between these splitters and more MoCA-compatible models may matter. MoCA allows a max of 57 dB loss between nodes, with a given link's budget loss being the minimum sum of insertion losses and output port isolation losses between two nodes (see pages 13-16), with a properly-installed "PoE" MoCA filter helping to keep losses to a minimum (see here). The choice of splitter matters little with just one splitter in the setup; however, the choice of component becomes more critical as the number of splitters goes up.

edit: p.s. This isn't a splitter at all:


hostage said:


> Splitters Purchased:
> https://www.amazon.com/Pack-Holland-Dishpro-Satellite-Diplexer/dp/B00684D77A


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## krkaufman (Nov 25, 2003)

hostage said:


> I did try stringing a tivo mini to the out of a moca adapter ...


That will get you nowhere because MoCA adapters that have RF/STB Out pass-through ports are using an internal diplexer, feeding the MoCA frequencies to the adapter's MoCA (coax-to-Ethernet) circuitry and only passing the sub-MoCA frequencies through the pass-through port.

There's no MoCA signal for the Mini to find when connected to the MoCA adapter's pass-through port.



hostage said:


> Now I wonder if I should have had a splitter on that 0_o.


Yes, you could have used a splitter to connect the MoCA adapter and Mini to the coax plant, separately. Or you could have connected the Mini via Ethernet to the same switch to which the MoCA adapter was connected (assuming a free switch port; if none, connect the Mini and MoCA adapter to a network switch, and connect the switch to the microcell).


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## hostage (Jul 27, 2004)

Sorry it took so long to reply, wife made me move a lot of things around and wasn't sure what exactly the way we were going, though I think I finally have a solution. Got a new AP so I can keep the router in the basement with all the AV and rest of the networking gear. 

If I place a splitter between Moca Adapter and the 2 way 5-2k splitter, I have connection issues to the Tivo Mini3. I then replaced the splitter with a coupler and it improved immediately. I still need to check the terminations on one cable, though wondering what else I can do to improve things. I do have the Tivo Roamio pass through the Moca. I don't know if that is better or worst than a splitter.

I do have a unused Moca adapter, though I am trying to figure out where to place it as adding additional that additional splitter caused issues. I did replace the 5-900 splitters with the 5-2k. I have another moca adapter that I want to user in another part of the house, though would like to figure out where to go with the splitters.

Should I just use the house supplied 5-900 splitters? Ditch the diplexers or 5-2k splitters? Is there anything else I should get?


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## snerd (Jun 6, 2008)

Your diagram needs more details about which ports of the devices are connected to each cable. For example, the MoCA adapter will actually block MoCA signals between the two coax ports, so this connection will work properly only if the "Device" or "STB/OUT" port (labeling depends on which MoCA adapter you have) is connected to the Roamio. The other RF port should connect to the IN port of the 2-way splitter. If connected properly, using the pass-through of the MoCA adapter will provide stronger signals than you would get from adding another splitter.

I don't recommend using a coupler in place of the splitter, as that might cause reception problems for the OTA signals. I'm guessing that you had the wrong connections to the splitter, and that prevented the Mini V3 from getting good MoCA signals. Try the 5-2K splitter that you already have. This particular configuration can't really benefit from a "MoCA rated" splitter.

The diplexer should have the OTA+PoE connected to the VHF/UHF port, the Mini connected to the SAT port, and the IN/OUT port connected to coax that runs to one of the outputs of the 2-way splitter.

Hope that makes sense. The parts you already have should work fine once everything is connected properly.


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## krkaufman (Nov 25, 2003)

snerd said:


> I'm guessing that you had the wrong connections to the splitter, and that prevented the Mini V3 from getting good MoCA signals.


This comment also makes me wonder about the spec of the splitter used when the disruption occurred...


hostage said:


> If I place a splitter between Moca Adapter and the 2 way 5-2k splitter, I have connection issues to the Tivo Mini3.
> ...
> Should I just use the house supplied 5-900 splitters?


In a word... NO. Any 900 MHz splitters are almost certainly an impediment to a healthy MoCA network (operating at 1125 MHz and higher).

What brand & model # are the 2K splitters you're using? The frequency rating of a splitter isn't determinant relative to its MoCA compatibility.*** The general recommendation, when current splitters don't seem to be supporting a stable MoCA setup, is to upgrade to known-good MoCA 2.0-compatible splitters: Holland's GHS-PRO-M series (see here) or Verizon's MoCA 2.0-rated splitters.

Also, in addition to @snerd's suggestion to make sure the MoCA adapter's "IN" ("Network") port is connected to the input of the 2-way splitter; and upgrading any splitters used to GHS-PRO-M's; you'd want to extend your MoCA network by attaching the input of an appropriately-sized splitter to the main 2-way splitter's output currently connecting to your Mini v2, keeping the current 2-way in place at the top level to maintain the OTA signal strength delivered to the Roamio, and locating the MoCA adapter at the top of the tree. (Other configurations are also possible, but this would most closely map to your suggested setup.)

edit2: e.g.:





​
*** edit: p.s. Are the 2K splitters being used the same ones I previously cautioned about...


krkaufman said:


> ... the splitters you linked are seemingly designed for satellite setup use. (They're listed under "Satellite TV Equipment," have satellite frequency specs, and the power passing is an additional hint.) These splitters would not be ideal for a MoCA setup, since, being designed for satellite, they would have higher output port isolation at MoCA frequencies (1125-1675 MHz, within the satellite frequency range) .... rather than intentionally lower output port isolation, as found in the Holland GHS-PRO-M (e.g.) and Verizon MoCA 2.0-rated splitters.
> 
> 'gist: The frequency spec on a splitter isn't determinant regarding its relative suitability for a MoCA setup.
> 
> The components linked may work, but the cumulative difference between these splitters and more MoCA-compatible models may matter.


... ???​


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## hostage (Jul 27, 2004)

Amazing how some people have different answers. I have the diplexer setup properly with the moca filter attached to the right part. I am currently using those 5-2000k that you warned me about 0_o. It isn't that often that people get to tell me "I told you so".  One splitter that was left from Time Warner was 5-900, though I do have 2x 3 way splitters that are rated for 5-1000. I am guessing those won't work well either.

I think I will need the following:
2x2 way splitter
1x3 way splitter

I could also replace the 2-way splitter that the Mini V2 is connected to with a 3-way, yank the OTA line out of the wall and have the Mini V2, V3, and OTA cable w/ Moca filter plug into that 3 way splitter. This would remove the need for the Diplexer. Would this be better? Basically remove diplexer and plug Antenna w/ moca filter and V3 into the same splitter as the V2 mini.


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## snerd (Jun 6, 2008)

hostage said:


> Amazing how some people have different answers.


Not amazing at all -- none of us have complete information about how your equipment is connected, since your diagrams don't specify which ports are connected to each segment of coax. That makes a huge difference to how the RF signals flow on the network. For example, a 2-way splitter doesn't behave as if 3 wires are shorted togther -- signals flow between the input and each output, but are mostly blocked from flowing from one output to another output. So, the exact connection to each port matters. This is more true of diplexers.

So, we're forced to guess what could be wrong, and it isn't very likely that all of us will make the same guess. More detail could easily help us figure out where the problem lies. Help us to help you.


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## hostage (Jul 27, 2004)

snerd said:


> Not amazing at all -- none of us have complete information about how your equipment is connected, since your diagrams don't specify which ports are connected to each segment of coax. That makes a huge difference to how the RF signals flow on the network. For example, a 2-way splitter doesn't behave as if 3 wires are shorted togther -- signals flow between the input and each output, but are mostly blocked from flowing from one output to another output. So, the exact connection to each port matters. This is more true of diplexers.
> 
> So, we're forced to guess what could be wrong, and it isn't very likely that all of us will make the same guess. More detail could easily help us figure out where the problem lies. Help us to help you.


This was more into reference to some other forums/reviews I have read, though this seems the most reliable form of details I have found so far.


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## hostage (Jul 27, 2004)

In short, I went ahead and ordered the Holland moca compatible splitters, for $12 shipped from TTS, it isn't much. I will let you guys know about the results.

I got 2x2 and 2x3 way splitters. I don't need all of them, though gives me room to redo a couple things, if I choose. I guess I will donate the satellite ones I ordered to a local thrift shop. I will keep the diplexer in the current spot, unless someone says otherwise. Thanks again for the help so far, have a bit of juggling right now. I feel better using something that is meant for this, then questioning the quality of the other splitters I purchased.


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## mdavej (Aug 13, 2015)

I think your filter on the antenna is redundant. The diplexer is enough.
Confused about installation


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## hostage (Jul 27, 2004)

Guess that explains why I wasn't getting the emails for this thread, had it set to my old college email that I haven't used in 14 years lol!

Anyway it was weird, I don't know if the diplexer was causing issues or not. The connection was good enough to get streaming videos of the internet, though not good enough to maintain a connection for the shows recorded to the TiVo and even OTA. I did the following and it seems to be great. I put additional splitters I did not have before and it seems to be running great...so far! I did want to follow this up as I hate open ended threads where it has all the problems you are having, though the person solves it w/o following up. This is what I ended up doing:

1) Removed diplexer
2) pulled OTA line out of house and plugged it into a 3-way MOCA Splitter. I also think my coax termination was bad on the OTA line as the whole body twisted around the connector so I don't know if it was grounded great. 
3) Added additional MOCA adapters where I just had couplers. I did everything above and when it started working, I then added these into the mix. It looks like the MOCA splitters really helped. 



Thanks for the help!


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## snerd (Jun 6, 2008)

Replacing couplers with splitters should have helped clean up your OTA signals. At the locations marked "spare drop to random room", if there are rooms that have nothing connected to the coax, you should place a 75-ohm termination on the wall plate to ensure that your OTA signals are clean throughout the house.


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## krkaufman (Nov 25, 2003)

hostage said:


> 3) Added additional MOCA adapters where I just had couplers.


Can you elaborate on what this bullet means?

It's too late for a before snapshot, but you may find value in checking the MoCA stats on one or more of your MoCA-connected Mini's.


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## fcfc2 (Feb 19, 2015)

hostage said:


> Guess that explains why I wasn't getting the emails for this thread, had it set to my old college email that I haven't used in 14 years lol!
> 
> Anyway it was weird, I don't know if the diplexer was causing issues or not. The connection was good enough to get streaming videos of the internet, though not good enough to maintain a connection for the shows recorded to the TiVo and even OTA. I did the following and it seems to be great. I put additional splitters I did not have before and it seems to be running great...so far! I did want to follow this up as I hate open ended threads where it has all the problems you are having, though the person solves it w/o following up. This is what I ended up doing:
> 
> ...


Well, congratulations on getting your MoCA network up and working, but I can only say your diagrams puzzled me. I guess the first question I have is, are all those drops going to "random outlets" being used for anything. If not then, the splitters which are feeding them should be able to be replaced by either a lower port splitter or a coupler which you don't show, but report using?? 3GHz couplers are the recommended ones to use if possible to replace a splitter when possible. If you want to extend your MoCA network for computers, MoCA wireless adapters or whatever then keep them but otherwise these drops / splits add unnecessary loss.
Confused about how you were using the diplexer. The correct way is to invert the diplexer and have the OTA antenna connected to coax coming from the antenna, and in your case, either the input or the "Sat" leg can be used to connect to the coax network or the nearby mini. Was this how you had it connected? If you install it correctly, there is little need for an additional MoCA filter, but if your signal strength is not an issue it will do no harm to keep it.
I agree that the MoCA splitters you are now using helped you get the MoCA network running, but in general the fewer the splitters, the fewer the # of ports the splitters being used, the better it is for both your MoCA network and the OTA reception for your DVR.


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## snerd (Jun 6, 2008)

fcfc2 said:


> Well, congratulations on getting your MoCA network up and working, but I can only say your diagrams puzzled me. I guess the first question I have is, are all those drops going to "random outlets" being used for anything. If not then, the splitters which are feeding them should be able to be replaced by either a lower port splitter or a coupler which you don't show, but report using?? 3GHz couplers are the recommended ones to use if possible to replace a splitter when possible. If you want to extend your MoCA network for computers, MoCA wireless adapters or whatever then keep them but otherwise these drops / splits add unnecessary loss.


I suspect that the couplers fcfc2 describes (a short barrel connector with two female F-type ends) is different than the couplers that hostage was using (3-way junction that looks like a tiny 2-way splitter, but acts by directly shorting the three ports together). If I'm right about this, putting the couplers back in play would be a bad idea.


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## krkaufman (Nov 25, 2003)

hostage said:


> 3) Added additional MOCA adapters where I just had couplers.





fcfc2 said:


> If not then, the splitters which are feeding them should be able to be replaced by either a lower port splitter or a coupler which you don't show, but report using?? 3GHz couplers are the recommended ones to use if possible to replace a splitter when possible.


By "coupler" I believe @hostage means something different than you (and I) envision(ed). I don't believe they're referring to a F81 connector (e.g., e.g.), but some other splitter-like component that I've never run across. @snerd has recommended use of such a coupler in a setup or two, recently, for a specific benefit, but I can't find the posts, at the moment.


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## fcfc2 (Feb 19, 2015)

snerd said:


> I suspect that the couplers fcfc2 describes (a short barrel connector with two female F-type ends) is different than the couplers that hostage was using (3-way junction that looks like a tiny 2-way splitter, but acts by directly shorting the three ports together). If I'm right about this, putting the couplers back in play would be a bad idea.


https://www.amazon.com/10pcs-Frequency-Barrel-Connectors-Couplers/dp/B0037JB75S
These, barrel connectors, are what I am suggesting vs the multiple splitters if those "random" ports are not needed. This is what I had guessed?, where what the OP was referring to as I am unfamiliar with what you are referring to as "couplers". Here is what Amazon seems to be referring to as "couplers"....basically what I am calling barrel connectors, https://www.amazon.com/RiteAV-4330136515-Coax-Coupler-Premium/dp/B000V1PAVM.


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## krkaufman (Nov 25, 2003)

snerd said:


> I don't recommend using a coupler in place of the splitter, as that might cause reception problems for the OTA signals.


Heh, one mention by @snerd was in this very thread, but it was a recommendation NOT to use such a "coupler" on the basis that it could affect OTA reception -- which the OP's summary seems to have confirmed.


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## JoeKustra (Dec 7, 2012)

krkaufman said:


> Heh, one mention by @snerd was in this very thread, but it was a recommendation NOT to use such a "coupler" on the basis that it could affect OTA reception -- which the OP's summary seems to have confirmed.


He moved: Roamio Basic w/ OTA Antenna - Pre-amp/amp question


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## snerd (Jun 6, 2008)

krkaufman said:


> By "coupler" I believe @hostage means something different than you (and I) envision(ed). I don't believe they're referring to a F81 connector (e.g., e.g.), but some other splitter-like component that I've never run across. @snerd has recommended use of such a coupler in a setup or two, recently, for a specific benefit, but I can't find the posts, at the moment.


OK, now I guess I'll need to elaborate even more. You're link to a "splitter-like component" gives a somewhat bogus hand-wavy explanation of a "directional coupler". True directional couplers are used on the big coax that runs underground and/or strung from telephone poles. These act like a very unbalanced 2-way splitter which sends a tiny fraction of the power out the "tap" that runs to your house, while sending the vast majority of the power down the street to the next tap point. This allows RF power to be distributed efficiently through cities/neighborhoods.

I'm guessing that hostage is using a beast that I've called a "joiner" that might look like this or that or the other and unfortunately they use words like "splitter" and "combiner" to describe them, but they do not function as true splitters. These junctions simply short together the center wires of the three ports, which is absolutely guaranteed to introduce major reflections of any RF signals on the coax plant. Sometimes reflections are a good thing in a MoCA network (e.g. from a PoE filter) and MoCA can adapt somewhat to compensate, but for OTA/catv signals it is always best to avoid any reflections, which is why true splitters are preferred, and also why it is best to terminate unused ports with a 75-ohm termination.


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## scole250 (Nov 8, 2005)

Be gentle if this a bad idea, but what about a 6 way splitter where each output only has an 11 db loss, like this? http://a.co/8haIxdc


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## fcfc2 (Feb 19, 2015)

scole250 said:


> Be gentle if this a bad idea, but what about a 6 way splitter where each output only has an 11 db loss, like this? Amazon.com: BAMF 6-Way Coax Cable Splitter Bi-Directional MoCA 5-2300MHz: Home Audio & Theater


I have tested the MoCA performance of that brand and it did not perform quite as good as the Verizon and Holland MoCA rated splitters for MoCA.
The diagrams provided are IMO a bit misleading, and therefore a single multiport splitter will not work because the coax runs are not continuous from one central source (homerun wiring), that is, one or more of the splitters pictured are in different rooms/locations, often referred to as "cascaded" splitters. Further complications, the OP is setting up an OTA signal with cable internet. IMO these are extra difficult because of the need to keep the OTA signals and the cable company signals separated or isolated from each other and again this makes for using one multiport splitter pretty much impossible.


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## krkaufman (Nov 25, 2003)

scole250 said:


> Be gentle if this a bad idea, but what about a 6 way splitter where each output only has an 11 db loss, like this? Amazon.com: BAMF 6-Way Coax Cable Splitter Bi-Directional MoCA 5-2300MHz: Home Audio & Theater


Not possible for the OP (@hostage) owing to the physical layout of their setup, as best depicted in their latest diagram over in their new thread, linked above. They currently require 3 splitters owing to their cable plant not being home-run.

edit: What fcfc2 said, but less.


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