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need some help re: splitters/diplexers...

1723 Views 24 Replies 10 Participants Last post by  4HiMarks
I'm not sure exactly what I need, so let's start with a straightforward technical question - Can I add an additional OTA signal into a cable that is diplexed, or do I have to un-diplex (uniplex?) it first?

I have one of those POS Terk clip-ons on my Dish, which diplexes an OTA antenna signal with the output from my Dish(es). I would like to join/merge/inject/whatever the coax (TV2) output from a ViP622 onto that so it will show up in the UHF band on my other TVs.

So, in other words, can I take the cable(s) coming from my roof, attach it to one input on the double side of a splitter/combiner, attach the TV2 coax to the other input, and then run a single cable from the single side to a diplexer, from which the Sat signal would go to another STB and the OTA to an antenna input?

Or do I have to run it into the diplexer first, then combine the OTA and TV2, then diplex the combined signal back with the Sat feed to get back down to a single cable run?

(Not that this should be relevant to the answer, but I intend to attach the OTA cable to a CECB with analog passthrough so this question does NOT become moot after February 17).

-Chris
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Diplexers must be used in pairs, and there should only be "wire" between them (barrel connectors work fine - just not splitters).

My preferred way to handle situations like yours is to keep DIsh / antenna separated from distribution networks. So, I would run coax from the TV2 output directly to the room where the CECB/other satelite receiver is going, and join the TV2 and antenna there.
scooper said:
Diplexers must be used in pairs, and there should only be "wire" between them (barrel connectors work fine - just not splitters).

My preferred way to handle situations like yours is to keep Dish / antenna separated from distribution networks. So, I would run coax from the TV2 output directly to the room where the CECB/other satelite receiver is going, and join the TV2 and antenna there.
It already has one coax. I'm trying to avoid running another one.
-Chris
I don't think you should use the same wire coming down from the antenna as sending your TV2 output to the other receiving station. At the very least, you could potentially be broadcasting without a license material that you aren't authorized to. Likelyhood of getting in trouble for this is pretty slim (unless a neighbor is close enough to complain).
scooper said:
I don't think you should use the same wire coming down from the antenna as sending your TV2 output to the other receiving station. At the very least, you could potentially be broadcasting without a license material that you aren't authorized to. Likelyhood of getting in trouble for this is pretty slim (unless a neighbor is close enough to complain).
Well I live in a TH, so there is certainly that possibility, but everyone around has cable, satellite, or FiOS, so it's not something I'm going to lose any sleep over. The dish is on the back of the roof and there are only trees behind me. I don't think it is going to happen anyway though.

Here's what I would like to happen EVENTUALLY - 622 downstairs in the HT room, another one upstairs in the BR. Both feeding HD to both locations (long HDMI cables, cat 6, wireless??? don't know yet), and SD to the living room (Well, HD someday...). Probably other locations as well. I have a rat's nest of wires running all over already, and would prefer not to add to it. In fact, I'd like to eliminate as many as I can (WAF, ya know).

We're getting new paint and carpet/floors all over, and as part of the makeover the bed moves to the other side of the room and we get a flat panel for the wall where it was. Luckily, that wall is closer to the current 622 and also near the closet for the new one. I'm trying to simplify things from the jury-rigged setup going on now.

Oh yeah, in addition to the Terk, I also have a Winegard yagi on a rotator since I'm halfway between DC and Baltimore with the towers pretty much 180 degrees apart. I mostly use the Terk for Balt. and the yagi for DC, but usually watch DC locals from E*.

-Chris
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I understand the WAF, but I have a VERY understanding wife :D - she just wants it to work - and since we just had a rainstorm go through - it isn't. Had to admonish her to call Dish to get a tech out.
man, since you are doing all of this work to your house...NOW is the time to wire it the RIGHT way.

pull out all of the old cable if it doesnt fit whats below:

wire at least 1 RG6 cable rated to 2250 Mhz to each room in your house, or at least each room that MAY eventually have TV. run them from each room to your DEMARC (like near your eletrical panel). Run Appropriate 2250 Mhz RG 6 from your Dishes to the same Demarc. Run separate antenna cables from the Terk and the Yagi to the Demarc (can be RG59).

Install proper grounding for all dishs/antennas at the demarc.

now, you can do everything you want now and in the future at the Demarc.

you are a good candidate for a Home Distribution Amp like HomeZ0ne from dish.

everything else and be diplexed and split out/combined...etc right at the demarc.
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Topcat,

That's essentially the way it already is, but I'm looking at a situation involving way more than just one cable. Each 622 has three inputs (2 sat, one OTA) and two outputs (one HD, one SD). Plus I am trying to combine 2 OTA sources. So to really do it "properly" I'd need about 5 cables running to (for example) the HT room -sat tuner 1, sat tuner 2, Terk, Yagi, and TV2 output from the other 622. That can be reduced somewhat by diplexing, but it would be helpful if I could combine in the demarc first. Hence my question.

The 4 cables coming from the Terk are already diplexed - nothing I can do about it - they're built in. I would like to combine that with additional signals in the demarc before sending it off to the rest of the house. I wanted to know if I have to buy 4 pairs of diplexers to add TV2 output to the lines.

I did not know E* offered a Home distro amp. I have been toying with such an idea for a long time, but never found anything suitable for my purposes and budget. I have never heard of Home Zone or seen anything about anything like it on their web site. Where can I find out more about it?

-Chris
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Off-air signals and TV2 signals share the same frequency band, so they should not be diplexed together. Diplexing is for combining two signals *on different frequencies* into one cable.
The purpose of the TV2 modulator being able to output on a wide range of channels was for you to be able to place the TV2 output channels in areas where you don't have OTA channels to interfere with.

This is exactly what it was made for.
I don't think you all are understanding what I have been asking. I know what diplexers are for. I am sending my TV2 signal on a frequency that is different from the OTA signals in my area. What I don't know is whether diplexers do anything to change the signal, making it impossible to add TV2 to a line that is ALREADY diplexed.

There should be no problem taking TV2, and an OTA signal, and joining them together with a splitter/combiner, since the frequencies are different, right? It will be especially easy after 2/17/09 since TV2 is outputting on UHF 60 and 62, which are outside the band to be kept.

Now, if I took that combined signal, I could diplex it with a sat signal onto one cable for transmission to another room where it would be un-diplexed back into an NTSC signal fed to an analog tuner, and a sat signal fed to a E* STB. So far so good?

Here's the twist - My Terk clip-on has diplexers built in. So the cables come down from the roof into my demarc with Sat and OTA signals already diplexed together. Call that cable A. TV2 comes back to the demarc from my 622 on another cable, cable B. I want to send both the diplexed signal from the roof, and the TV2 signal from my 622, to a STB and TV in another room using only one cable. Can I just run cable A and Cable B into a splitter/combiner, send the output to the other room, and un-diplex it as above?

Or does diplexing do something that requires me to get another pair of diplexers, un-diplex cable A into its component sat and OTA signals, combine the OTA with TV2 on cable B with a splitter/combiner, then re-diplex the result with the sat signal back onto a single cable again to go to the other room, where it will be un-diplexed for the final time? What does all this diplexing and un-diplexing do to the signal strength?
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Get rid of the POS Terk antenna with the built in diplexers.

Run DEDICATED lines for an OTA antenna as well as your DBS lines to your central wiring.

Now you should be able to do what you're asking.
scooper said:
Get rid of the POS Terk antenna with the built in diplexers.

Run DEDICATED lines for an OTA antenna as well as your DBS lines to your central wiring.

Now you should be able to do what you're asking.
That still doesn't answer my question. Is there a technical reason, disregarding your (and my) opinion of the quailty of the Terk, why I can't do what I'm asking. I'm not interested in getting rid of it at present as it allows me to pick up Balt. and DC at the same time without rotating my yagi.

-Chris
Your POS Terk is what is preventing your idea from working.
scooper said:
Your POS Terk is what is preventing your idea from working.
How, specifically? Please provide more details. Don't all diplexers work the same?

-Chris
Look dude - is there an antenna input directly into the Terk, or not ? That's your problem.
scooper said:
Look dude - is there an antenna input directly into the Terk, or not ? That's your problem.
Of course not. It IS an antenna! Why would it? My yagi doesn't have one either.

-Chris
IIP said:
Off-air signals and TV2 signals share the same frequency band, so they should not be diplexed together. ...
This is simply not correct.
Your problem is that the Terk antenna has a diplexer built into it and the antenna requires power from the sat. receiver to work.
BNUMM said:
Your problem is that the Terk antenna has a diplexer built into it and the antenna requires power from the sat. receiver to work.
Aha. Now we're getting somewhere. I always wondered where it got its power from.

So, you're saying that the power "signal" travels back up the diplexed line, and would interfere with the TV2 signal if I just tried to combine them? I'm envisioning something like a feedback loop, although that's not exactly what would happen if the TV2 and sat signal cables for the two receivers were swapped.

-Chris
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