# MoCA with Tuning Adapter - New Splitter Needed?



## JstnAllndr (Dec 22, 2003)

Hi, all. I tried searching the forums but just need a quick answer for my situation.

I have a Roamio (basic) with a Tuning Adapter connected via ethernet to the cable modem right next to it. I will be setting up a TiVo Mini tonight in my bedroom that only has a cable outlet. I read on the forums MoCA does not play nice with tuning adapters.

Right now my cable set up is this:
Outlet->2-way splitter->Modem
___________________->Tuning Adapter->Roamio

Will I need to purchase a 3-way splitter and a second POE filter?
Outlet->3-way splitter->MoCA->Modem
___________________->TiVo
___________________->POE->Tuning Adapter

Thanks!


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## samsauce29 (Nov 30, 2007)

From everything that I've read on here, the 3-way splitter sounds like the way to go. 

Both my moca network and my tuning adapters have performed better since I added splitters and poe filters a month ago.


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## tarheelblue32 (Jan 13, 2014)

JstnAllndr said:


> Will I need to purchase a 3-way splitter and a second POE filter?
> Outlet->3-way splitter->MoCA->Modem
> ___________________->TiVo
> ___________________->POE->Tuning Adapter


Yes, this is the way to go. I would also recommend that the 3-way splitter be an unbalanced 3-way rather than a balanced one, and I would put the cable modem on the stronger output. I think the balanced 3-way splitters use an internal tap to get the 3 balanced outputs, and MoCA sometimes doesn't play well with taps.


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## Dan203 (Apr 17, 2000)

You don't need to POE filter. The POE filter is designed to prevent the MoCa signal from leaking out to your neighbors. Hence the name Point Of Entry. MoCa shouldn't cause any issues with the equipment inside your house.


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## tarheelblue32 (Jan 13, 2014)

Dan203 said:


> You don't need to POE filter. The POE filter is designed to prevent the MoCa signal from leaking out to your neighbors. Hence the name Point Of Entry. MoCa shouldn't cause any issues with the equipment inside your house.


Cox disagrees with you:

http://media.cox.com/support/print_media/tv/equipment/user_guides/cable_box/InstallingYourMotoTA.pdf


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## Dan203 (Apr 17, 2000)

tarheelblue32 said:


> Cox disagrees with you:
> 
> http://media.cox.com/support/print_media/tv/equipment/user_guides/cable_box/InstallingYourMotoTA.pdf


I don't know why they say that. MoCa is designed to operate on frequencies outside those used by your normal cable. It can technically overlap some frequencies above 500Mhz but it should auto detect your system and switch to a channel that does not overlap. (or you can manually set it if you want) Even if you have a 1Ghz system there is a whole range of channels in the D band that operate in the 1150-1500MHz range.


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## BigJimOutlaw (Mar 21, 2004)

For whatever reason, moca and tuning adapters do sometimes cause issues together. Mostly Time Warner folks are experiencing it. The easiest way to resolve is another POE filter on the TA.


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## webcrawlr (Mar 4, 2004)

Dan203 said:


> I don't know why they say that. MoCa is designed to operate on frequencies outside those used by your normal cable. It can technically overlap some frequencies above 500Mhz but it should auto detect your system and switch to a channel that does not overlap. (or you can manually set it if you want) Even if you have a 1Ghz system there is a whole range of channels in the D band that operate in the 1150-1500MHz range.


Have you tried selecting a channel other than D1 (1150) using 1Ghz splitters? I have and my PHY rates tanked. Putting in Holland 2Ghz splitters (HFS4D) allowed me to use any channel above that. I'm currently on D6 (1300) and my PHY rate is hovering around 275. I suspect moving MoCA up higher could help with the interference some devices seem to suffer from but doing so with 1Ghz splitters will most likely do so at the expense of PHY rates (speed).



BigJimOutlaw said:


> For whatever reason, moca and tuning adapters do sometimes cause issues together. Mostly Time Warner folks are experiencing it. The easiest way to resolve is another POE filter on the TA.


It's not just TAs, some cable modems don't do well is strong MoCA signals either.


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## Dan203 (Apr 17, 2000)

That begs the question... If MoCa can technically operate between 500-1500Mhz which frequencies do POE filters block and how do they not knock out real channels? If they're based on the original 875Mhz spec then wouldn't they knock out all channels in the 875-1000Mhz range for those on 1Ghz systems? 

I never really paid attention to which frequencies a POE filter actually blocks. Until today, when I read the spec, I didn't even realize it operated on frequencies below 1Ghz. I assumed all MoCa frequencies were above 1GHz to prevent interference with real channels.


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## Dan203 (Apr 17, 2000)

Or is it one way, only blocking those frequencies on outbound signals?


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## saeba (Oct 12, 2004)

I just setup MoCA in my home. We have 3 TiVo's all with cablecards and tuning adapters (Bright House). The only POE filter I installed was at the house entry point and so far have had no issues with the tuning adapters.

I setup three-way splitters at the TiVos - one to TiVo, one to Tuning Adapter and one to Actiontec MoCA adapter. I haven't seen any signal degradation.

The way Bright House setup my feed is that I have a two-way splitter with one connection going to my cable modem, the other to a three-way splitter to the TiVos. I placed the POE right before the three-way splitter so I didn't affect the feed to the cable modem. I don't know that it would have affected the cable modem, but no point in taking that risk.


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## tatergator1 (Mar 27, 2008)

Dan203 said:


> Or is it one way, only blocking those frequencies on outbound signals?


On all the POE filter's for Cable systems I've seen, the blocking starts at >1005 MHz and they are not one way. They are typically configured such that they can only be installed one way, but signals >1005 MhZ will be bounced back on whichever side of the line they are present. For example, the MoCA in the house is bounced back into the home wiring, any errant MoCA signals present outside of the house will be bounced back out into the exterior wiring.


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## Dan203 (Apr 17, 2000)

tatergator1 said:


> On all the POE filter's for Cable systems I've seen, the blocking starts at >1005 MHz and they are not one way. They are typically configured such that they can only be installed one way, but signals >1005 MhZ will be bounced back on whichever side of the line they are present. For example, the MoCA in the house is bounced back into the home wiring, any errant MoCA signals present outside of the house will be bounced back out into the exterior wiring.


So if your MoCa network is set to Auto and selects a channel that uses a frequency below 1050MHz then the POE filter is doing nothing.

And that still doesn't explain why Cox would suggest using a POE filter before the TA like that. If they only block frequencies above 1GHz then how would it help a TA, or cable modem, in any way? Those use standard cable frequencies, below 1GHz, so how would having a POE filter in place help? Unless they're poorly designed and subject to interference from frequencies that shouldn't even effect them.


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## BigJimOutlaw (Mar 21, 2004)

Retail and Cable utilize the D-band of the moca spec (1150-1500 range). POE filters pass-through around 5-1000-ish (unless otherwise indicated) and reflect everything else, so that's why they're effective at controlling those moca networks.

The other moca bands (500 through 1025MHz) are reserved for satellite (E or F), telco (C) and whatever other applications might exist.

Don't know exactly what is happening when moca interferes with some TAs and cable modems, but I suspect moca's particularly strong signal has something to do with it.


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## tarheelblue32 (Jan 13, 2014)

The Actiontec MoCA adapters that TiVo sells only operate between 1150Mhz and 1500Mhz, and I'm pretty sure the built-in MoCA on the TiVo boxes are the same.


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## Dan203 (Apr 17, 2000)

OK that makes sense, the part about D band anyway, and confirms what I always assumed about MoCa before I actually read the spec. 

The Cox setup guide that was posted threw me off and made me question my understanding of how MoCa worked. Seems that the use of an extra POE filter in that situation is for blocking unintended interference, but technically should not be required.


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## webcrawlr (Mar 4, 2004)

saeba said:


> I setup three-way splitters at the TiVos - one to TiVo, one to Tuning Adapter and one to Actiontec MoCA adapter. I haven't seen any signal degradation.


So you aren't using the output of the Actiontec MoCA adapter? If not I'd try dropping to a two-way and put the TA on the output of the MoCA adapter. I recall reading somewhere that the MoCA adapter acts like a diplexer and only passes signals under 1000Mhz to the output.



BigJimOutlaw said:


> Don't know exactly what is happening when moca interferes with some TAs and cable modems, but I suspect moca's particularly strong signal has something to do with it.


Correct. MoCA adjusts the signal level (db) on the fly to the minimum level needed to maintain successful transmission. So if full power isn't needed it's not used. There's a catch though, the controller node regularly sends out beacons at full power for new node discovery. So if you have non-MoCA devices on your coax segment where MoCA signals are present that strong signal basically can lessen their ability to pick up those sub 1000Mhz signals.


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## tarheelblue32 (Jan 13, 2014)

webcrawlr said:


> So you aren't using the output of the Actiontec MoCA adapter? If not I'd try dropping to a two-way and put the TA on the output of the MoCA adapter. I recall reading somewhere that the MoCA adapter acts like a diplexer and only passes signals under 1000Mhz to the output.


He needs the 3-way splitter. If you look at the diagram on his post, it shows that the output of the MoCA adapter goes to his cable modem.


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## nooneuknow (Feb 5, 2011)

Wow, I'm late to the party on this thread...

As a Cox customer, on a 1GHZ HFC RF cable network, I can say that it is very important (when using MoCA) that Cisco STA1520 TAs have a PoE filter on the splitter "Out" leg feeding the TA, and the TA's "Out" port go unused. I put terminators on mine, just to keep with the modern cable network best practices, of leaving no port unterminated (whether that port self-terminates without anything connected is an unknown).

It looks like the thread has self-corrected to get to this same conclusion. I'm just a bit shocked that a few members seem to have never heard about this, nor understand the "why" and "how" of it all...

I've preached until my keyboard has no more visible letters, on the subject matter (and on a few other select topics I'm deeply versed in).

The note about balanced 3-way splitters is factually correct, in that in order to be "balanced", a directional coupler is used in combination with a splitter (internal to the splitter as a whole), and DCs don't always play well with MoCA (but sometimes are actually required, or the best thing for a certain situation).

What is interesting about, say an eight way splitter, is that it's internally a two-way, feeding two more two-ways, then feeding four two-ways, and the outs of those are what feed the eight-way "Out" ports.

One thing that is often not stated, is that a TA can be fed by (nearly) any coax run. It does not have to be from adding a splitter for TiVo & TA. You could home-run your TAs, if you wanted to, and the readings came out good. But, with MoCA, that still requires a PoE filter to prevent TA malfunctions, and the reason for the required non-use of the TA Out port, is the internal TA "equalizer" (amp), lacking a proper internal PoE filter and MoCA bypass path, only found in amps made for playing well with MoCA. Even some (older) cable modems require an added PoE filter. That's due to the same interference and intermodulation that can be caused by sending high power (high dB) frequencies, into a device not designed to be exposed to them. Such devices can malfunction, or simply suffer degradation of the signals it is meant to deal with.


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## tarheelblue32 (Jan 13, 2014)

nooneuknow said:


> Also, any splitter with an odd, rather than even, number of "Out" ports, will have a DC internally


My understanding of splitters is that an *un*balanced 3-way splitter does not do this, because it is essentially a 2-way splitter with a second internal 2-way splitter on one of the outputs of the first internal splitter. So, an unbalanced 3-way splitter should work okay with MoCA whereas a balanced 3-way splitter should be avoided.


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## nooneuknow (Feb 5, 2011)

tarheelblue32 said:


> My understanding of splitters is that an *un*balanced 3-way splitter does not do this, because it is essentially a 2-way splitter with a second internal 2-way splitter on one of the outputs of the first internal splitter. So, an unbalanced 3-way splitter should work okay with MoCA whereas a balanced 3-way splitter should be avoided.


I removed the quoted line, as it was stated as an "absolute", whereas whether or not DCs are used, internally, varies, and they can be found in some splitters with any number of ports, and it takes some calculating of the -dB value of the out ports to determine if any are used internally.

You are 100% correct in your understanding of 3-way balanced versus unbalanced. However, the DC in a balanced splitter can still have a purpose and place in a MoCA network. It's just something to be taken into consideration, as a part of the whole. I wouldn't go as far as to say no DCs should be used, or that balanced 3-ways are unsuitable, period.

For those who are able to make diagrams of their network, it should be easy to figure where, if applicable, to place a balanced three-way. Just as it was said to use the lower-loss port on an unbalanced one for a cable modem, I can also say that the layout of the ports on a balanced one can often give away what ports are going through the coupler, and you can use that to also decide which one to use for a CM, that might run "hot" using the former recommendation.

In the KISS category, yes, you might just be better off not using a balanced three-way, instead using an additional two-way and terminator, in order to bring the level down on a specific coax run (or a four way in place of the balanced three-way, plus a terminator, if that works out for all associated runs).


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## HarperVision (May 14, 2007)

BigJimOutlaw said:


> ........Don't know exactly what is happening when moca interferes with some TAs and cable modems, but I suspect moca's particularly strong signal has something to do with it.


I would say that's most likely it and probably pertains to the harmonics of the moca signal's frequencies, if it's as powerful as you guys are reporting. The first harmonic of moca freqs like 1GHz, 1250MHz, 1500MHz etc are 500, 625, & 750MHz, smack dab in the cable band.


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## saeba (Oct 12, 2004)

webcrawlr said:


> So you aren't using the output of the Actiontec MoCA adapter? If not I'd try dropping to a two-way and put the TA on the output of the MoCA adapter. I recall reading somewhere that the MoCA adapter acts like a diplexer and only passes signals under 1000Mhz to the output.


I'm using Actiontec ECB3500T01 units and there is no coax output on these.


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## JstnAllndr (Dec 22, 2003)

I appreciate all the replies! Went by Radio Shack and laughed when they wanted $21 for a cable splitter. So I tried it at home without it, and lo and behold it works!

I have a 2-way splitter feeding a cable modem on one output and the tuning adapter pass through to the TiVo on the other. Seems to be working fine. (Bright House with a Cisco tuning adapter).

Now I just have to figure out Bright House wants to raise my cable bill $50 when I returned my only cable box...


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## tarheelblue32 (Jan 13, 2014)

JstnAllndr said:


> I have a 2-way splitter feeding a cable modem on one output and the tuning adapter pass through to the TiVo on the other. Seems to be working fine. (Bright House with a Cisco tuning adapter).


The pass-through on the tuning adapters will often interfere with MoCA signals. If your Mini has trouble communicating with the Roamio, that is probably why.


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## ellinj (Feb 26, 2002)

Cox recommended POE filters on all DOCSIS devices, including the TA and my modem. In fact the TA self install kits I got from Cox included them.


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## nooneuknow (Feb 5, 2011)

ellinj said:


> Cox recommended POE filters on all DOCSIS devices, including the TA and my modem. In fact the TA self install kits I got from Cox included them.


I failed to mention (in my prior posts) that my Cox market provides those "self install kits", free of charge, as well (and returning the kits are not required, and will be declined, if turning in a TA or CM).

They include everything you could possibly need. Cox wouldn't issue them, with every TA and modem, if the cost of the parts inside, wasn't worth it.


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## Bigg (Oct 31, 2003)

Wow, I'm glad I don't have to deal with all this TA crap!

Couldn't the OP use a 2-way and do?:
Leg 1>>>TA>>>TiVo
Leg 2>>>MoCA>>>modem


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## nooneuknow (Feb 5, 2011)

Bigg said:


> Wow, I'm glad I don't have to deal with all this TA crap!
> 
> Couldn't the OP use a 2-way and do?:
> Leg 1>>>TA>>>TiVo
> Leg 2>>>MoCA>>>modem


No. The Cisco STA1520 TA can still malfunction, unless it has a PoE filter keeping the MoCA from getting into to IN port.

Actually, everything is just wrong with such a setup, if you are going to use MoCA. Even without MoCA, some have had issues with the quality of the EQ amp found inside TAs with an OUT port, causing more issues than it is worth, to use in-line. Unless an amp has an internal PoE filter to keep the MoCA from passing into the amp, and a bypass, to send the MoCA through unadulterated (as-is), no amp belongs in-line on a MoCA pathway.

I've seen maybe a total of six members claim that they set up everything exactly the opposite of what is suggested, and it works fine. Of those six, I think three came back later, asking why their TiVo or MoCA adapter was reporting insufficient bandwidth, or something else was acting up...


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## tarheelblue32 (Jan 13, 2014)

Bigg said:


> Wow, I'm glad I don't have to deal with all this TA crap!
> 
> Couldn't the OP use a 2-way and do?:
> Leg 1>>>TA>>>TiVo
> Leg 2>>>MoCA>>>modem


I definitely wouldn't recommend it. When I tried using the RF output on my tuning adapter to connect to my Roamio Plus, the tuning adapter completely blocked my Roamio Plus from being able to communicate over MoCA. A 3-way splitter is the way to go in this situation.


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## nooneuknow (Feb 5, 2011)

tarheelblue32 said:


> I definitely wouldn't recommend it. When I tried using the RF output on my tuning adapter to connect to my Roamio Plus, the tuning adapter completely blocked my Roamio Plus from being able to communicate over MoCA. A 3-way splitter is the way to go in this situation.


Exactly. I used to always say pretty much the same. But, there's always those pesky few who somehow manage to get just enough MoCA through the TA, to wind up with the status saying the MoCA link is up. More common, are those who have inadequate RF strength to begin with, and using a splitter takes everything out, as they are right on the edge of "working" (mostly non-MoCA users report this), thus reporting the in-line method is the way to go.

There's always a 1%er out there, just waiting to counter any post made with absolutes, like "that won't work" or "MoCA can't get through a TA", etc...


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## Bigg (Oct 31, 2003)

nooneuknow said:


> No. The Cisco STA1520 TA can still malfunction, unless it has a PoE filter keeping the MoCA from getting into to IN port.


But in that case, since the Base Roamio doesn't have MoCA, all it needs is RF, so couldn't the OP put the MoCA filter ahead of the TA and TiVo? The TiVo shouldn't have an issue being behind a MoCA filter, since it doesn't have MoCA, hence the whole point of the MoCA adapter on the other leg.

Or is there some reason, independent of MoCA, that the TA doesn't do a good job of passing <870mhz RF to the TiVo?


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## tarheelblue32 (Jan 13, 2014)

Bigg said:


> But in that case, since the Base Roamio doesn't have MoCA, all it needs is RF, so couldn't the OP put the MoCA filter ahead of the TA and TiVo? The TiVo shouldn't have an issue being behind a MoCA filter, since it doesn't have MoCA, hence the whole point of the MoCA adapter on the other leg.
> 
> Or is there some reason, independent of MoCA, that the TA doesn't do a good job of passing <870mhz RF to the TiVo?


Okay that's a good point. I guess in that case it wouldn't hurt to try using the RF output. I just really don't trust anything about the tuning adapters. They are cheaply made pieces of crapola. I would still recommend the 3-way splitter as the better option over using the RF output on the tuning adapter.


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## nooneuknow (Feb 5, 2011)

tarheelblue32 said:


> Okay that's a good point. I guess in that case it wouldn't hurt to try using the RF output. I just really don't trust anything about the tuning adapters. They are cheaply made pieces of crapola.


Several members have reported the TA was still compromising the CATV RF signal, even without MoCA. I had many more issues with losing many more channels (when the TA would get in a fault state), if I didn't use the splitter method, and that's with no MoCA.

Every 6 months, or so, somebody will report how their TiVo wouldn't work, not using the RF out of the TA.

Those usually chalk up to those with very weak signals (I've managed to waterboard specifics from some of them) right from the demarc, and that one extra split just does is too much. Unfortunately, rather than take advice to get their MSO to fix the signal, they just report that using the out port of the TA is "the only way to go", based on their vast experience with one TA, often their first TA.

I have had 6 TAs in operation, at the same time (before my Roamio upgrade). Even the TAs can interfere with other TAs, causing mayhem, or all of them to go down. It's best not to rely on them any more than absolutely necessary.


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## Bigg (Oct 31, 2003)

tarheelblue32 said:


> Okay that's a good point. I guess in that case it wouldn't hurt to try using the RF output. I just really don't trust anything about the tuning adapters. They are cheaply made pieces of crapola. I would still recommend the 3-way splitter as the better option over using the RF output on the tuning adapter.


Yeah, I guess if you have a hot enough line for that, it's not a bad idea, but even with a 2-way at the home run location with everything else off the other leg and then a 3-way at this location, that's quite a bit of loss.



nooneuknow said:


> Several members have reported the TA was still compromising the CATV RF signal, even without MoCA. I had many more issues with losing many more channels (when the TA would get in a fault state), if I didn't use the splitter method, and that's with no MoCA.
> 
> Every 6 months, or so, somebody will report how their TiVo wouldn't work, not using the RF out of the TA.
> 
> Those usually chalk up to those with very weak signals (I've managed to waterboard specifics from some of them) right from the demarc, and that one extra split just does is too much. Unfortunately, rather than take advice to get their MSO to fix the signal, they just report that using the out port of the TA is "the only way to go", based on their vast experience with one TA, often their first TA.


Interesting. The problem is, some locations just don't have a lot of signal coming in. I guess in that case, an amp is going to be required, if only to overcome the extra splitters. What a bunch of kludgery!


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## macwhizROC (Mar 14, 2007)

The TAs are based on old pre-MoCA designs. They usually have an internal amplifier to make up for signal loss from the internal splitter between the TA itself and the output port. That amplifier does not do nice things to the TiVo's MoCA signal, and it may hurt TV reception if your signal levels aren't great to begin with. So, plugging the TiVo into the TA's output port may cause problems with TiVo Mini units connected via MoCA. Better to have the TA and TiVo connected to individual ports of a splitter.

Additionally, the TAs weren't designed to see very strong incoming signals on the MoCA band. With the TiVo being so close in terms of wire length, the MoCA signal can overpower the TA's tuner, causing intermittent operational problems. This problem also occurs with pre-MoCA cable modems; recent cable modems have a built-in MoCA filter to prevent this. In the case of TAs, you need the MoCA filter between the TA and the splitter to keep the strong MoCA signal from creating interference. (Sure, Cisco and Arris could redesign the TAs from a modern cable modem design to fix this. We all know that's not likely.)

It's also a good idea as a general practice to install another MoCA filter between the incoming cable line and the first splitter in your house, to keep the MoCA signal from leaving your house. Otherwise, it's possible that your neighbors could see your MoCA network. By default, MoCA doesn't use encryption, so without a MoCA filter blocking your signal from the street, any neighbor with a MoCA adapter could essentially be plugged into your home network. Even if the security issues don't worry you... do you want your neighbor's MoCA devices eating into your TiVo MRV network's bandwidth?


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## Bigg (Oct 31, 2003)

macwhizROC said:


> The TAs are based on old pre-MoCA designs. They usually have an internal amplifier to make up for signal loss from the internal splitter between the TA itself and the output port. That amplifier does not do nice things to the TiVo's MoCA signal, and it may hurt TV reception if your signal levels aren't great to begin with. So, plugging the TiVo into the TA's output port may cause problems with TiVo Mini units connected via MoCA. Better to have the TA and TiVo connected to individual ports of a splitter.


That's interesting. Although only the RF portion of that applies to the OP, since we're talking about a Roamio Basic, without built-in MoCA.



> Additionally, the TAs weren't designed to see very strong incoming signals on the MoCA band. With the TiVo being so close in terms of wire length, the MoCA signal can overpower the TA's tuner, causing intermittent operational problems. This problem also occurs with pre-MoCA cable modems; recent cable modems have a built-in MoCA filter to prevent this. In the case of TAs, you need the MoCA filter between the TA and the splitter to keep the strong MoCA signal from creating interference. (Sure, Cisco and Arris could redesign the TAs from a modern cable modem design to fix this. We all know that's not likely.)


Wow, what a crappy design! I know for a fact that some older modems were designed properly to only handle the frequencies they were designed to handle (<860mhz in the case of DOCSIS 2). My parents are running MoCA from their Comcast whole-home DVR and it does not negatively affect their SB5100, which was purchased in 2003 when Comcast first enabled DOCSIS on their system for the then 1.5/256 service. That modem will finally be retired at some point in the next 6 months, either for an SB6141 or an eMTA if they get Comcast phone.



> It's also a good idea as a general practice to install another MoCA filter between the incoming cable line and the first splitter in your house, to keep the MoCA signal from leaving your house. Otherwise, it's possible that your neighbors could see your MoCA network. By default, MoCA doesn't use encryption, so without a MoCA filter blocking your signal from the street, any neighbor with a MoCA adapter could essentially be plugged into your home network. Even if the security issues don't worry you... do you want your neighbor's MoCA devices eating into your TiVo MRV network's bandwidth?


Yeah, I know it's best practice. My parents have a MoCA filter that was installed when they got whole-home. I don't have one, and my MoCA network is encrypted. My thought is if there is anyone on my tap that also has MoCA, it's most likely for X1, in which case they would have a filter. I even asked the cable guy about it one time, as he said don't worry about it. Our plant can't reliably pass a channel at 615mhz (it's a 625mhz plant that doesn't quite get there), so I'm not too worried about an 1150mhz signal going much farther than the one tap!

I would say that when I own my own house, I would do it right, but then again I hope to be in a FIOS area.


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## nooneuknow (Feb 5, 2011)

Some of the earlier Motorola DOCSIS 2 cable modems shipped with defective filtering for >860MHz, requiring a cable modem-only trap to be installed, like a PoE filter, on the coax going into the CM. This was a problem with regular 1GHz CATV signals, no MoCA needed to suffer from slow internet, and malfunctions, if in a 1GHz market (>860MHz).

Since I'm on a Cox network, that uses all of 1GHz, and found I could get 2x the speed by using a trap on my DOCSIS 2 CM, I automatically put a trap on my DOCSIS 3 modem. That actually disabled 4 of my 8 downstream QAM channels, requiring removal, as they use 4 < 860MHz & 4 > 860MHz, even for mid-tier data packages. 12 and greater downstream QAM channels are used for their Ultimate tier.

For MoCA, unless you can find any reference that a coax-connected device has MoCA filtering, there's always a chance some things will run better, if not exposed to the higher frequencies, but even more of a factor is the strength of those frequencies, and what role harmonic interference between the higher and lower frequency bands play.

Harmonic interference can be present, without there being a smoking gun, or malfunctioning device, just plain old "not as good/fast as things could be", until you check to see if adding more filters/traps helps...

ETA: Harmonic interference is a good reason NOT to use splitters rated greater than 1.2GHz, under the false assumptions people often make when they hear that MoCA operates higher than 1GHz, that they must then need 2GHz or 3GHz splitters. 860Mhz will work for most not on a 1GHz network, and 1.2GHz isn't even used by Cox on their 1GHz network. They will take out self-installed splitters rated any greater than 1.02GHz, even though their own whole home system uses MoCA, on the same bands as retail MoCA.


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## Bigg (Oct 31, 2003)

nooneuknow said:


> Some of the earlier Motorola DOCSIS 2 cable modems shipped with defective filtering for >860MHz, requiring a cable modem-only trap to be installed, like a PoE filter, on the coax going into the CM. This was a problem with regular 1GHz CATV signals, no MoCA needed to suffer from slow internet, and malfunctions, if in a 1GHz market (>860MHz).
> 
> Since I'm on a Cox network, that uses all of 1GHz, and found I could get 2x the speed by using a trap on my DOCSIS 2 CM, I automatically put a trap on my DOCSIS 3 modem. That actually disabled 4 of my 8 downstream QAM channels, requiring removal, as they use 4 < 860MHz & 4 > 860MHz, even for mid-tier data packages. 12 and greater downstream QAM channels are used for their Ultimate tier.
> 
> ...


Interesting. That's some weird stuff. In their case, the MoCA doesn't negatively affect the speed. Their modem consistently pulls 27/6 (25/5 package), which is about the practical limit for DOCSIS 2 equipment.

The problem with your logic about 2ghz (satellite splitters) is that most regular cable (860mhz) splitters pass everything, likely up to several ghz.

It sounds like Cox dug themselves into a hole with their absurdly difficult to manage 1ghz plant, versus the standard 860mhz plant. I wonder if they will abandon 1ghz and go back to 860mhz when they finally get around to killing off analog?

Comcast doesn't really care what you have, as long as it works. However, their plants are mostly 860mhz or less, and as far as I can tell, they don't really have anything above about 750mhz. Why they don't add more HD channels, I don't know, but that seems to be about what they're doing. They may not want to open the gap between lower frequency systems, like mine, at 625mhz and the rebuilt systems at 860mhz any more than they already have, with the former having about 70 HD's and the latter having about 120 HD's, along with some additional SD's.


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## nooneuknow (Feb 5, 2011)

Bigg said:


> The problem with your logic about 2ghz (satellite splitters) is that most regular cable (860mhz) splitters pass everything, likely up to several ghz.


A lower rated splitter should still provide some attenuation, going by the same logic that you use to posit others may have no need for a PoE filter, at the very place they were designed to be placed, and for the very purpose they were first created for. You often state that your local network techs claim your MoCA won't get far, anyway, and I respectfully try not to say anything. If I do, I just point out that you have a low top-frequency plant and network, while I'm on a high top-frequency plant and network, and it's a YMMV matter.

I'm well aware that an 860MHz splitter doesn't contain the components for a reject band, thus doesn't just have a hard-stop at 860MHz.

Think about it for a little bit, before you respond, please. Both are YMMV, based on plant/network engineering/top-frequency and how far away the copper runs, before it hits a fiber backbone.


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## Bigg (Oct 31, 2003)

nooneuknow said:


> A lower rated splitter should still provide some attenuation, going by the same logic that you use to posit others may have no need for a PoE filter, at the very place they were designed to be placed, and for the very purpose they were first created for. You often state that your local network techs claim your MoCA won't get far, anyway, and I respectfully try not to say anything. If I do, I just point out that you have a low top-frequency plant and network, while I'm on a high top-frequency plant and network, and it's a YMMV matter.
> 
> I'm well aware that an 860MHz splitter doesn't contain the components for a reject band, thus doesn't just have a hard-stop at 860MHz.
> 
> Think about it for a little bit, before you respond, please. Both are YMMV, based on plant/network engineering/top-frequency and how far away the copper runs, before it hits a fiber backbone.


That's the plant though. I fully expect my MoCA signal is in good shape at the tap, once it tries to go into the plant, however, it gets attenuated off extremely rapidly.

MoCA may well go farther in a rebuilt (860mhz) plant than it would on my aging 625mhz plant, but it still shouldn't really matter. In theory, it's always best to have a MoCA filter, although reality seems to not care as much. You do have a point that the jump from 1000mhz to 1150mhz isn't that big, especially compared to the jump from 615mhz to 1150mhz so it might be wise to carefully select a MoCA filter that can pass everything below 1002, and block everything above.

In terms of splitters, MoCA is designed to blast through 860mhz splitters at 1150-1500mhz.

I think I've been pretty clear that YMMV and I'm on an aging plant that has severely limited capacity. It doesn't matter where the node is, we're talking about the RF side of things.


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