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Discussion Starter #1
i am having a house built, and just read it is recommended to get 4 cat 6s run from attic to central wiring closet.


can someone explain what each of the 4 Cat 6 wires do?


I am thinking I will have the directv on roof, wire run into the attic, then run down to the closet, and split out to separate rooms. Also, may install an Over the Air high def antenna in attic.
 

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Quote:
i am having a house built, and just read it is recommended to get 4 cat 6s run from attic to central wiring closet.
Maybe you should read the reply to your question, that you posted last week, in this thread.
 

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i guess i just did not understand that posting. why are there left and right all of a sudden? is that just part of the HDTV hookup? my Dual LNB just has 2.

The jargon was a little confusing.


So would this mean i need to run 5 RG-6s from attic to closet? 4 for HD Directv, and 1 for over the air HDTV??


thank you.
 

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Yes.


Edit -


In addition to Pat's post below, You need to keep in mind that each sat tuner needs its own cable from the multiswitch. The same idea is close on the OTA tuners of the HDTivo - each of them need their own feed from the OTA antenna. However, unlike the DBS tuners, you could use 1 cable (dedicated) from your OTA antenna down to the room, then use a conventional RF splitter. There maybe cases where it is more desireable to use dedicated cables for each OTA tuner as well - such as you had a distribution amp setup.
 

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AVSForum memebr DrDon has thoughtfully provided the following.


Polarization is used to double the number of transponders on a satellite. You can have two different transponders sharing the same frequency by polarizing the signal. Your STB works like this: You tune a DirecTV channel. Your box knows what transponder that channel is on. If it's on transponder one, your STB sends out 13v which tells the LNB to select the LH (left-hand) polarization and, hence, the odd numbered transponders. The LNB sends ALL of the odd-numbered transponders down to the STB which then tunes out all but transponder one. It then passes that digital stream on to the digital processor, which extracts the information necessary for the channel you selected.


Now, if you then select a DirecTV channel that's on transponder 8, your STB will send out 18v, telling the LNB to select the RH (right-hand) polarization and, hence, the even numberd transponders. You know the rest.


In a multi-satellite situation, you have a new problem in that the STB must be able to request the correct polarization, but the correct satellite. Transponder one on the 101 is the same frequency as Transponder one on the 119. So, obviously, you can't have send both sets of signals down the pipe at the same time... they'd interfere with each other. So, they devised a switch that uses an audio trigger. When you select a DirecTV channel from the 119 bird, your STB sends out the proper voltage for odd or even transponders ..PLUS, it sends a 22khz audio tone The switch hears the tone and switches from one satellite's LNB to the other. The switch passes the voltage to the appropriate LNB which does the rest.


A "multiswitch" Works like a telephone operator. The input lines to the multiswitch send a constant voltage to each of the 4 LNBs (2 for 101 and 2 for 119.. remember, they're DUAL LNBs) and receives back the transponders associated with that voltage. The multiswitch then senses what the STB wants (by looking at the voltage and tone combination) and connects the STB to the proper line. The line going from the multiswitch to the STB never has more than one half of the transponders from either satellite on it at any given time.


The Sat-C arrangement uses a special trick to take some transponders off of the 110 bird and place them into unused slots on the 119. (The slots aren't really unused. Dish transmits programming on them). Since the original transponders on 110 are different from the slots on 119, a special LNB is required that will shift the frequencies to the slots. Then, a special combiner is used that strips out three of the Dish transponders from 119 and inserts the DirecTV transponders from 110 in their place.


And that, in a nutshell, is how the whole thing works. Again, this is a nutshell and not a perfectly technically accurate representation.


Doc
 

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Discussion Starter #6
First, thank you for the information.

Unfortunately, I did not understand some of it, but it is interesting nonetheless.


So am I right in thinking I need 5 cat 6s run to wire closet, 4 for the Directv dish, and 1 for the over the air antenna (2 signals could be combined on one cat 6 with a splitter).


thanks again.
 

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RG6, not cat6. RG6 is coax while cat6 is 4 twisted pair. 4 lines handle the D* signals.


1 13V 0KHz for odd transponders on Sat A at 101

1 18V 0KHz for even transponders on Sat A at 101

1 13V 22KHz for odd transponders on Sat B at 119

1 18V 22KHz for even transponders on Sat B/C at 119/110


1 for the OTA


You need a 5x cascadable multiswitch in the closet. Popular 5x8s include the Eagle Aspen S-4180-GX+ and the Terk BMS-58. An internet search can find one for under $80 and they work as well as the $300 and up Spauns.


Each of the 8 outputs can be separated into satellite and OTA signals with a diplexer that can be found for $3 on the net or $20 in stores. Run directly from the multiswitch output to the diplexer by the receiver. Do not put a splitter anywhere between the dish and the diplexer. The OTA leg off the diplexer can be split if needed but do not put a splitter on a satellite line. Inexpensive diplexers work as well as expensive ones.
 
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