MoCA PoE filter question with external OTA antenna (no cable TV)

[degrub]

Thank you very much for this! I don't suppose you have any diagrams handy you could share? . I would be interested to see how the set up for the point to point arrangement looks like. I am guessing I will need a power outlet in the roof for the MoCA adapter / modem. However if I were to opt for the lower cost option and had to install an amplifier, will it be as follows?
OTA Antenna----Amplifier----PoE filter-----7 way splitter

Yes.
And the moca modems and switch really need to be in conditioned space, otherwise if the air temperature gets above 32 C, you may get heat caused failures eventually.

 

[LexCaia]

At the central point you have 5 moca modems, one connected to each cable. The ethernet port on each connects to a 8 port gigabit switch

Thanks again degrub! Having lightbulb moments . I guessed that was what you meant but wasn’t sure. If the central point for me is the roof, I assume I will require power outlets in the roof for each MoCA modem.

you have issues getting a strong enough TV signal to one of the rooms after all of the changes, you will need to add a low noise tv amp as close to the antenna as you can get and before the splitter, which may be in the attic.

Will the Amp be after the PoE filter but before the splitter?

what coax type do you have ?

Given the age of the home, likely a RG6. I guess there is no way of testing the type of cable from the TV outlet without accessing the cables from the roof or pulling the TV socket out?

 

[LexCaia]

Yes.
And the moca modems and switch really need to be in conditioned space, otherwise if the air temperature gets above 32 C, you may get heat caused failures eventually.

Our summers get really hot over here (into the 40sC or 110F). Unfortunately no air conditioning in the roof so the point to point option may not be viable for me. Given my main aim is to get wired Ethernet backhaul, having the two MoCA modems / adapters may achieve this for me. Hopefully cables are RG6 too. Once I have the inspection done by the cabler I’ll know more too. Thanks again for all the information and detailed explanations…..have learnt a lot!

 

[Tech Junky]

TV outlet

It's printed on the cable. Pull the wall plate off and look at the cable.

 

[LexCaia]

It's printed on the cable. Pull the wall plate off and look at the cable.

Have not pulled it out before but will give it a go when I get a chance later this evening after work. I probably used the incorrect terminology earlier by calling it a TV socket . Thanks again!

 

[degrub]

Thanks again degrub! Having lightbulb moments . I guessed that was what you meant but wasn’t sure. If the central point for me is the roof, I assume I will require power outlets in the roof for each MoCA modem.

Given the temperatures in an attic based on 45c, placing modems and a switch in the attic is a no go. You would have to have the cables moved into conditioned space.

Will the Amp be after the PoE filter but before the splitter?

A OTA TV signal amp is always the closest device to the antenna. So between the antenna and the moca POE filter. The DC power injector for the AMP can be anywhere between the antenna and the splitter.

Again, try without the AMP first. You may not need it.

Given the age of the home, likely a RG6. I guess there is no way of testing the type of cable from the TV outlet without accessing the cables from the roof or pulling the TV socket out?

Get access to a cable somewhere. Usually the impression or printed label is every few feet.

 

[krkaufman]

can I place the filter instead at each tv outlet? Would that prevent the MoCA signal from broadcasting through the antenna?

Actually can I get away with only having the MoCA filters on the outlets where I have a MoCA adapter or does it really need to go to each TV wall outlet? (assuming I can't place the filter at the source on the lead in cable from the antenna)?

I’m still working through the thread but an incorrect response on this front compels me to reply…

This absolutely would NOT work. MoCA filters BLOCK MoCA SIGNALS, so installing filters in this manner would block MoCA signals from even exiting the rooms. (So, yes, it would prevent MoCA signals from emanating from the antenna … by preventing MoCA signals from even hitting the coax outlets, let alone the central OTA splitter or through its input to the antenna!)

 

[krkaufman]

I have a separate coax wall outlet in my lounge for my NBN NTD modem with cabling from an underground pit. This is separate to the OTA antenna and cabling to the rest of the TV outlets in each room. Incidentally there is also a TV outlet in the lounge.

This is key: any coax associated with your Internet connection is fully, physically isolated from your OTA antenna coax (Which could have been assumed, given both your Internet connection and TV tuning are currently functional. Had the coax segments been linked, the OTA signals would have interfered with your Internet connection, and the Internet signals would have messed-up your TV channel tuning.)

I believe I will however need a PoE filter before my NBN NTD modem.

Nope.

As you’ve detailed, intending to use the “OTA” coax for MoCA, no MoCA signals would be present on the “Internet” (“NBN NTB”) coax segment, precluding any need for a “PoE” MoCA filter on *that* coax to keep MoCA signals from escaping onto the Internet provider’s premise.

And if the provider uses DOCSIS, the isolated modem feed also future-proofs your setup against conflicts between MoCA and DOCSIS 3.1, 4.0 and beyond — what with the DOCSIS 3.1 and later spec frequency ranges encroaching upon and then fully overlapping the MoCA frequency range. (MoCA Band D was designed to coexist with DOCSIS 3.0, but the evolving DOCSIS specs are making coax sharing of MoCA and DOCSIS increasingly difficult and, eventually, impossible.)

DOCSIS vs MoCA Sidebar:​

* MoCA Extended Band D: 1125-1675 MHz​

* DOCSIS 3.0: up to 1002 MHz​

* DOCSIS 3.1 “initial rollout”: up to 1218 MHz​

* DOCSIS 3.1 “full”: up to 1794 MHz​

​

​

By the way, if you get the chance, could you resend the link above as I would love to read it. I tried to open it but received a "Sorry couldn't find the page error".

Understanding that the linked configuration is moot, try copy/pasting the following URL (the original had a space in front of “com” and I can’t get SNB to not corrupt the link):

https://www.amazon.com/gp/customer-reviews/R3AKBUGFGGTPX5?ASIN=B013J7O3X0

This config isn’t relevant because it describes a hybrid setup lacking an isolated coax feed for the modem location — unlike the OP config, which has separate isolated coax segments available. Quite fortuitous.

I have read conflicting posts that a filter is needed on the lead in cable from the OTA antenna before the splitter to prevent MoCA from broadcasting? I have no idea if it does or not.

You *will* want a “PoE” MoCA filter (or equivalent) at the top of your OTA coax’s MoCA scope, both to keep the MoCA signals from hitting and emanating from the antenna, but also to gain the reflective performance benefit of the “PoE” MoCA filter — which, worst case, can help overcome deficiencies of sub-optimal splitters. (In other words, the priority would be simply getting a “PoE” MoCA filter installed on the input of your main “OTA” splitter, and then check the MoCA performance/efficiency to determine if further improvements are required/desired.)

I am guessing it should work without a PoE filter but I will run the risk of the MoCA signal broadcasting through the antenna.

Mostly correct. The sub-optimal splitter at the top of your “OTA” segment may affect MoCA connectivity/performance, but a MoCA filter on its input port would improve the odds/performance. (But if you’re getting up there to install the filter, it might make sense to kill both birds.)

You can try it sans the “PoE” MoCA filter on the OTA coax, but don’t get discouraged if it doesn’t work … at all or as well as you’d like … and plan to get the components optimized, both for performance and to prolong the life of your MoCA adapters (since more efficient means they can run at lower power/heat levels).

You will very likely need an OTA TV signal amp at the closest point to the antenna due to the additional coax connections. You want this before combining with MOCA signals. Preferably on the antenna mast.

A *perhaps* better way to phrase it would be that IF amplification for the OTA antenna signal is found to be needed…

• any in-line amplifier would need to be installed upstream of the MoCA network (i.e. between the OTA coax’s “PoE” MoCA filter and the antenna), to prevent the MoCA signals from passing through the amplifier; or,
• if a distribution amp is used, replacing the top-level OTA splitter, you’d want to use a “designed for MoCA” amplifier, with circuitry designed to keep the MoCA signals from hitting the internal amp circuitry or passing to/through the amp’s input port.

 

[Tech Junky]

(the original had a space in front of “com” and I can’t get SNB to not corrupt the link):

That's why I had to put the damned space in the link because it wouldn't work correctly w/o it. I also sent the info from the review directly in a PM as to not clutter the thread. All the stuff you're saying about where to put things has been stated though.

The easiest solution is to have NBN rub a direct connection to the CM and then everything is still isolated on the TV side.

The biggest issue seems to be it's a rental and OP doesn't / can't access the roof to isolate the Antenna / OTA signal at the main splitter.

This could all be condensed into a couple of replies with proper access to the points in which the coax is being used.

 

[krkaufman]

I did this quick layout diagram ...

Diagram looks GOOD, with the caveats previously cited:

• No "PoE" MoCA filter is needed on the Internet modem line;
• A "PoE" MoCA filter is required on the input of the top-level "OTA" splitter;
• The 2-way splitter in the remote room(s) could be skipped if the chosen MoCA adapter has an RF pass-through port (to which the TV could be connected).
  
  
• Amplifier shouldn't be necessary if one isn't currently required, though the attenuation/specs of the replacement splitter may be marginally more severe.

---
edit: p.s. Re: the diagram and the "7-way splitter" ... Most splitters that size are either 6-way or 8-way (6 outputs or 8 outputs), so I'm wondering whether that's actually a 6-way/6-output splitter or an 8-way/8-output splitter with an unused output. Ideally, the splitter would be right-sized to just the number of splits/outputs needed, to minimize signal loss (both OTA and MoCA), and any unused output ports would be capped with a 75-ohm terminator. That said, given your issues accessing the splitter, you can make the argument that oversizing the central splitter and connecting all lines that you may want to use in the future would make sense, decreasing the need to access the splitter location in the future.

 

[krkaufman]

The issue I have is that the source splitter which feeds from the lead in cable from the OTA is in the roof where I can't access,

Regarding the impossibility of getting the "PoE" MoCA filter properly installed upstream of the top-level OTA split (i.e. as an absolute last resort) ...

* How many rooms are you looking to link to your router? Just the one additional room w/ the WAP/mesh node?
* Is there anywhere else in the home where the "OTA" coax lines to your router location and the room(s) targeted for MoCA are co-located and more easily accessible?

I'll defer suggesting the workaround absent confirmation of the conditions needed for it to work.

 

[krkaufman]

Have not pulled it out before but will give it a go when I get a chance later this evening after work. I probably used the incorrect terminology earlier by calling it a TV socket . Thanks again!

To be clear, MoCA can work over RG59 *and* through standard digital cable (1002 MHz) splitters. It's just that the added attenuation of sub-optimal components can balloon in a more complex setup, pushing the node-to-node path attenuation over MoCA's allowed limit of 57 dB. (The out-of-spec components also becomes more critical when using MoCA 2.5, since it wants to use almost the entire MoCA spectrum, shifting beyond the puny 50 MHz required for MoCA 1.1, but MoCA 2.5 can still power through and deliver full performance ... but requiring a higher power level for the MoCA gear to adjust for the attenuation.)

I recommend reviewing this IEEE presentation covering "MoCA Basics" (PDF). It's pretty straightforward and provides good insight on MoCA loss budgeting, preferred splitters, and the performance value of a "PoE" MoCA filter.

As for "designed for MoCA" splitters, the following series are all cited as having lower output port isolation in the MoCA frequency range (though less critical in a single splitter setup with a "PoE" MoCA filter installed, as explained in the above presentation):

• Holland GHS-2PRO-M
• Amphenol ABS312H MoCA 2.0 2-way
• Verizon FiOS MoCA 2.0 2-way
• Antronix MMC1002H-B

You'll just need to find a sibling properly sized for your "OTA" top-level needs.

 

[Tech Junky]

@krkaufman

MoCA PoE filter question with external OTA antenna (no cable TV)

Hi there.....I hope someone can help as I have spent hours (days) trying to find an answer to this but to no avail. I currently have a HFC NBN connection which is where the existing ‘pay TV’ or cable network can be used to make the final part of the NBN network connection. In this circumstance...

www.snbforums.com

If you look at my initial reply....

NBN <home run / barrel coupler to outlet> cable modem

OTA <filter> main splitter

I guess I should have left it at that and moved onto another thread to appease you.

 

[krkaufman]

Given my main aim is to get wired Ethernet backhaul, having the two MoCA … adapters may achieve this for me.

A solid link between a pair of MoCA 2.5 nodes is capable of 2500 Mbps shared throughput — a “TURBO” mode 25% boost over a 3+ node setup’s 2000 Mbps shared, owing to reduced MoCA link management overhead. If the MoCA adapters are equipped with Gigabit Ethernet ports, the link should perform near full-duplex Gigabit levels. If your wireless mesh nodes are equipped with 2.5 GbE ports (related SNB thread here), you might consider that when shopping* for your MoCA adapters, as a priority over an RF pass-through port.

- - -
* FWIW, a mostly up-to-date list of available MoCA adapters can be found >here<.

edit: added link to AIMesh 2.5 GbE backhaul thread

 

[krkaufman]

The moca (adapters) will run at the maximum sync speed they can. The diagnostic/configuration page will show it.

TL;DR: Any clue how to determine the MoCA signal amplification level for the common MoCA 2.5 adapters?

- - -
I’ve seen the common table reflecting the node-to-node PHY rates (shared by most brands of adapters since they all seem to use the same chipsets), but I haven’t seen what I became accustomed to when working with MoCA on TiVo boxes … the TX and RX power levels. The TX power level was very handy for gauging how hard the MoCA adapters were having to work to establish and maintain the MoCA connection, with a power range of -30 to +3 dB. +3 dB indicated max amplification of the MoCA signal and that the MoCA network may be at or beyond its attenuation limit, and that the PHY rates (and throughput) may begin to suffer. Absent this power insight, it’s difficult to compare the efficiency of different configurations.

 

[degrub]

I believe the Actiontec 6200 modems have it on their node info page.
Maybe their 2.5 modems do as well ?
I don’t have a pair to test with.

 

[LexCaia]

A OTA TV signal amp is always the closest device to the antenna. So between the antenna and the moca POE filter. The DC power injector for the AMP can be anywhere between the antenna and the splitter.

Again, try without the AMP first. You may not need it.

Will do, and thanks again!

 

[LexCaia]

This absolutely would NOT work. MoCA filters BLOCK MoCA SIGNALS, so installing filters in this manner would block MoCA signals from even exiting the rooms. (So, yes, it would prevent MoCA signals from emanating from the antenna … by preventing MoCA signals from even hitting the coax outlets, let alone the central OTA splitter or through its input to the antenna!)

Thanks for confirming - I guessed as much after I posted this....the filter would prevent the signal from moving around the coaxial cable.

Nope.

As you’ve detailed, intending to use the “OTA” coax for MoCA, no MoCA signals would be present on the “Internet” (“NBN NTB”) coax segment, precluding any need for a “PoE” MoCA filter on *that* coax to keep MoCA signals from escaping onto the Internet provider’s premise.

Great! Thank you!

 

[LexCaia]

And if the provider uses DOCSIS, the isolated modem feed also future-proofs your setup against conflicts between MoCA and DOCSIS 3.1, 4.0 and beyond — what with the DOCSIS 3.1 and later spec frequency ranges encroaching upon and then fully overlapping the MoCA frequency range. (MoCA Band D was designed to coexist with DOCSIS 3.0, but the evolving DOCSIS specs are making coax sharing of MoCA and DOCSIS increasingly difficult and, eventually, impossible.)

DOCSIS vs MoCA Sidebar:* MoCA Extended Band D: 1125-1675 MHz* DOCSIS 3.0: up to 1002 MHz* DOCSIS 3.1 “initial rollout”: up to 1218 MHz* DOCSIS 3.1 “full”: up to 1794 MHz

I believe the DOCSIS 3.1 NTD modem is still operating up to the 1002 Mhz range. It is an Arris CM8200 - I am unable to access the web interface but looking at published specs out there seems to suggest this.

 

[LexCaia]

This config isn’t relevant because it describes a hybrid setup lacking an isolated coax feed for the modem location — unlike the OP config, which has separate isolated coax segments available. Quite fortuitous.

Most of the diagrams I've come across seem to be a hybrid set up....I will have to check the frequency on my splitter (it was installed 15 years ago) and also try and get a PoE filter (assuming it has to be 5-1002 Mhz).