MoCA - Cannot establish coax connection

[lomarican]

We live in a rural area – no cable available and a very slow (5 MBS) AT&T dsl connection over our landline. When we built our home years ago, I ran individual coax runs to each room in the house and tied everything together in a central location. The central location is fed an over the air TV signal which is amplified and split out to 8 separate locations (always worked fine). When we purchased Netflix, we found the wireless connection to our play station to be maddening and I did the following:

Installed a dsl filter at the phone line access box and ran that to the central location and connected that to a modem. From the modem, I ran an Ethernet cable to an Actiontec 2.0. Module. I used a 2-way splitter to split the OTA signal to a 4 way splitter for 4 MoCA connections and a 4 way splitter for 4 non MoCA connections.


OTA SIGNAL

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AMPLIFIER

|

|

2 WAY SPLITTER

| |

| |

NON MOCA MOCA

| | | |

4 WAY SPLITTER ACTIONTEC 2.0 MODULE

| |

4 ROOMS 4 WAY SPLITTER

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4 ROOMS

This worked great for almost 2 years. Last week the phones went out for almost a week. Once everything was repaired, the MoCA system quit working. The Ethernet connection at the modem was good but the Actiontec Module would not establish a Coax connection. After spending several hours troubleshooting, the outcome is that as long as I DO NOT connect the antenna signal to the Actiontec Module (Coax In), the Coax connection is established and the Ethernet connection is established to all 4 rooms. As soon as I attempt to introduce the OTA signal to the Module, the Coax light goes out and the system no longer delivers an Ethernet connection to any of the 4 MoCA ready rooms.


Given that everything worked like a charm for months with no changes to anything, I find myself totally stumped. I have tried swapping Actiontec Modules, splitters, cables, etc. with no changes. I would be most grateful for any thoughts or suggestions. This is really driving me crazy…

Just looked at the post and the illustration does not post correctly - sorry... 2 way splitter goes to two different runs each consisting of a single 4 way splitter - one for video only and one for MoCA connections...

 

[tannebil]

An issue in the amplifier perhaps?

Bring all the MoCA adapters to the central point and wire them up with a new MoCA splitter and short pieces of cable to test that the adapters are all good. Bring the up one at a time and make sure they work. Faster and saves a lot of walking around.

 

[lomarican]

Thanks tannebil for the reply…

I had done everything you suggested before I posted including pulling the amplifier and testing its output. I found no problems with the hardware other than the coax connection problem as indicated in the post. Because I need the amplifier to deliver usable OTA signals throughout the house and because it had been working just fine, the one thing I did not try was to eliminate the amplifier altogether. Doing that does finally solve the coax connection issue but the OTA signal, without the amplifier, is too weak to supply all the rooms. SO, the amplifier is now a problem and I’m OK with that as long as I can replace the amplifier with something that will play nice with the Actiontec MoCA adapters…

Is there a particular OTA amplifier that I need to purchase? Brand Name, Model, etc.? I googled the availability of MoCA amps but really not sure that’s what I need or ultimately exactly what to buy. The TV signal definitely needs to be amplified to be usable. Again, any help would be most appreciated.

 

[tannebil]

I have only a vague idea of the technical details so you really need an expert. It might be caused by the amplifier creating interference in the frequency ranges used by MoCA. If it was working fine for before, that makes me think that either the amplifier malfunctioned or something has corrupted the signal from the antenna like a corroded connection or a ground fault which is creating signals in the MoCA frequency range and the amp boosts the noise enough to cause a problem. But I'm drawing on ham radio experience from 50 years ago so I'd assign this analysis a confidence level of 3/10.

A cutoff filter that chops all frequencies above 900MHz on the antenna feed or after the amp might do the trick as well.

I ran across these guys who seem to deal with this kind of stuff. You might give them a call. At least they say the right words like amplifier, filter, antenna, and MoCA

http://www.pctstore.com/RF_Amplifiers_MoCA_Bypass_Amplifier_s/55.htm

 

[degrub]

Thanks tannebil for the reply…

I had done everything you suggested before I posted including pulling the amplifier and testing its output. I found no problems with the hardware other than the coax connection problem as indicated in the post. Because I need the amplifier to deliver usable OTA signals throughout the house and because it had been working just fine, the one thing I did not try was to eliminate the amplifier altogether. Doing that does finally solve the coax connection issue but the OTA signal, without the amplifier, is too weak to supply all the rooms. SO, the amplifier is now a problem and I’m OK with that as long as I can replace the amplifier with something that will play nice with the Actiontec MoCA adapters…

Is there a particular OTA amplifier that I need to purchase? Brand Name, Model, etc.? I googled the availability of MoCA amps but really not sure that’s what I need or ultimately exactly what to buy. The TV signal definitely needs to be amplified to be usable. Again, any help would be most appreciated.

Channel Master CM-7777 or 7778 depending on the dB budget required. Mast mounted are very good. RG-6 cable.

BTW, do you have a lightning ground on the antenna feed cable ? Maybe that got bridged somehow and there is a ground bias on the OTA cable ?