# Comcast Internet/E* on same cable run?



## dandirk (Sep 30, 2008)

OK my house wiring is messed up. When the house was built 3 years ago they wired properly with single jacks/runs of coax to a central closet.

The basement wasn't finished and the previous owner decided to cheap out and install splitters in the walls servicing 2 rooms/jacks with one run from the basement closet.

It just so happens 1 room is my office with the internet connection and the other (shared wall) has my TV.

I know this is pretty much a futile question...

Is there a way to merge the two signals (comcast internet and DishTV) at the cable run, then split them back out again at the devices? Essentially allowing both Comcast Internet and DishTV?

I would rerun the cable but my house is a messed up split level so doing the runs would force me to cut all sorts of holes in the drywall everywhere (main cable closet is on the opposite side of the split arrrggg...)


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## harsh (Jun 15, 2003)

It is difficult to predict what will happen. The cable modem standard provides for fairly broad spectrum coverage but your local yokel may only use a small subset. If they use low frequencies, you may get away with diplexing. If they don't, you won't.


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## dandirk (Sep 30, 2008)

Read a bit about diplexing and SWM, still a bit confused...

With diplexing I assume one unit merges the 2 signals (if compatible) to the one run. Then before each device there is another unit that splits it again?

My wiring is pretty much like this...

www_dandirksen_com)/wiring.jpg (sorry not enough posts)

So a diplexer would go before the 2in 8out splitter and the there would be another diplexor at both the TV and internet?

Is there a way to tell what signal my current internet provider uses? I think I can access the web admin tool of my modem...


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## dandirk (Sep 30, 2008)

hmm from my moterolla cable modem I found this 

Downstream: 687000000 Hz Locked

Upstream: 37200000 Hz Ranged

I am guessing this is 687 and 372 range... Will look into diplexors that might fit this...


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## dandirk (Sep 30, 2008)

Ok based on some more research those diplexers may work.

I have found a few brands that separate out ~5-800 Mhz and then 950-2250 MHz

I would post links but I can't at this time yet... come on 5 posts!!!

From what I have read, if merging then splitting cable internet and E* will work those would be it...

Now I have some basic question on where I might place these?

I am still reading up on the current installation methods, please correct me if I am wrong...

I only will have 1 DVR/receiver from directv (722 I believe). I only have 1 run coming from my attic to my closet.

I assume that would mean that a SWM will be installed and then split at the receiver to use both tuners?

For new installation are b-band splitters still used? Would that effect diplexing, or would be bband thingers be after the diplexer that splits the signal back out?

So progression of signal would be:

Dish - SWM (attic) - diplexer (closet) - wall - diplexor - bband (if needed) - receiver/DVR...

Cable/internet would be:

Cable Main - diplexer - wall - diplexor - cable modem


Does a SWM require power? Hmmm not sure if I have a outlet in the attic...


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## harsh (Jun 15, 2003)

I realize the the subject of the message is E* (so it probably should have been posted in an E* forum), but you're using DIRECTV terminology and that's dangerous when applied to DISH Network.

DISH Network doesn't offer a direct analog to the SWM. DISH's technology does allow two tuners to run off of a single cable where SWM technology allows up to eight tuners to run off of a single cable. DISH Network doesn't require B-band converters (nor does SWM technology).

You need to take a step back and learn the basic building blocks of the system you're considering before you set about to modifying it.

It is also important to watch your units when posting large numbers. The uplink frequency is 37.2MHz, not 372 MHz. You also need to understand that the frequencies may not be permanent. DOCSIS 2.0 (the cable modem standard) allows for uplink frequencies anywhere from 24-72MHz and downlink frequencies up to 860MHz. There is significant potential to trash your cable modem signal or your satellite signal (or both) if you don't do this right.


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## dandirk (Sep 30, 2008)

Thanks Harsh, You cleared up a bunch of stuff for me...

I tried to find a proper forum to post this in, but Dish does not have a installation forum like DirectTV.

After continued reading I am starting to learn more, like SWM is directv only pretty much. I just assumed the offerings of either would be very similar... You know what they say about assumptions.

Thanks for clearing up the modem frequencies, I just posted what the modem admin webpage listed and made an guess at the values based on what diplexers were out there... Nice to know the approximate high and low values.

No B-band converters to worry about... yeahhhh!

Guess my new home work is to find out if Dish uses anything below the 950Mhz range. 

I read about how the Dish service uses its own diplexers be able to send 2 signals with one cable. Have to confirm if this is how it still works and if the process uses anything below 950Mhz which is the cut off for most diplexers...


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## harsh (Jun 15, 2003)

DISH doesn't use the area below 1GHz other than for backfeeding from the two TV receivers. The diplexer will keep the 900MHz+ stuff out of your house.


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## cablewithaview (Jul 22, 2007)

As long as the Diplexer covers 5-2150, you should be ok. The diplexer does separate the vhf/uhf from the satellite frequency. Return runs around 29 mhz for most systems but may vary. We run our forward at 99 mhz (FM band). It varies from one company to another. Just need to make sure your connections are tight all the way through on both the modem and from the dish to the satellite. Any ingress can shut the reverse down on your internet. If you have problems with the internet, you can always disconnect the receiver first or dish to see if it changes or connect the wire straight through to see if that changes anything. I would suggest a single run to the modem to keep it free and clear of any issues on your end and the provider.


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## dandirk (Sep 30, 2008)

Thanks Harsh... I assume backfeeding is setting up a second tv from 1 receiver like the ViP722. Don't have to worry about that, my wiring won't support it in its current form I don't think. I was thinking of using cable TV (bare min package, locals to make internet cheaper) for my second TV in the "exercise"/dust collector room.

cablewithaview, thanks for confirming what I think _may_ work, I guess I will have to actually do it to find out.

I would love to have homeruns to both Receiver and Cable modem, if that were a possibility I would be all over it. Thanks for the troubleshooting ideas.

I will be posting in the Dish general forum (wish there was a Dish Installation forum) with my newly researched updated plans along with some general Dish specific installation questions (like how to get a 722 without hooking up a second tv)

Thanks for all the info guys, I am fairly "technical" and DBS is a bit more complicated then cable...


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