Originally Posted by b curry
The first PoE filter, coming from the utility pole in your diagram, is before the turner. That's why it's called a Point of Entry filter. The second filter you show would be redundant and would also block the MoCA modulated frequency form anything down stream of the second filter on your network.
The PoE filter works like a check valve. It permits bi-directional travel of TV and internet frequencies while blocking the reverse flow of the modulated MoCA frequencies. By blocking at the PoE you prevent access to your network from anyone out side your network with a MoCA adapter. The MoCA adapter modulates/de-modulates (codes/de-codes) your router frequencies to a higher frequency that co-exists on the same coax cable along with the TV and internet data frequencies. Your modem does more or less the same function by converting the incoming internet signal to a frequency that can talk to the router or a PC over CAT 5/6 cable. So, if you add and additional PoE filter up stream, you would block or reflect back any signal up stream of the filter from reaching anything on your network behind it.
I took the 2nd POE Filter out for now and also swapped out some parts to simplify the design a bit.
There is no advantage in this case to using the ECB3500. A half decent Gig Switch will allow the HTPC and ETH 6 to yack all they want. Another thought is to just run them both into the SBG6580, however, I prefer to leave the Primary Circuit to do what it does without complications.
As I recall Eric suggested the filter in front of the ETH 6 after reviewing the diagnostic of a troubled MoCA install. I have the feeling the Primary Circuit was cabled incorrectly (or maybe worse) and was causing modulation/de-modulation errors in the ETH 6. Perhaps the filter is not necessary in front of the tuner, if the MoCA Adapters are installed correctly.
Maybe I drew in the wrong kind of filter for immediately upstream of the ETH6/TA Splitter. I think the idea was to allow TA, CableCard and TV broadcasts in or out as necessary, and reflect or repel the MoCA pulse, thereby preventing MoCA interference to the TA and Tuner.
Here are Eric's words.....
A little farther down the page (post #30
) ckur6 claims it helped. I don't know though, so I am unprepared for a debate. All I do know is put it in-take it out and compare results, then I'll know.