# 2-way SWM Splitter vs Diplexer



## VDP07 (Feb 22, 2006)

A question out of pure curiosity. Performed a DISH service call the other day. Customer had a 722k. The TV2 picture quality was very poor. In checking the cabling in the attic, I found that the installer had used a DTV 2-way SWM splitter in place of the usual Holland or other brand Diplexer. I also noticed that he had connected the Sat. cable to the In port and the Receiver cable to the "dc power pass" out port of the splitter. (the opposite of what would be done using a diplexer) At the time, I didn't think to reverse the connections on the SWM splitter to check.

I replaced the SWM splitter with a correctly installed diplexer and all was good. Question, I know there are differences but are DTV 2-way SWM splitters essentially the same as a diplexor?


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## lugnutathome (Apr 13, 2009)

VDP07 said:


> A question out of pure curiosity. Performed a DISH service call the other day. Customer had a 722k. The TV2 picture quality was very poor. In checking the cabling in the attic, I found that the installer had used a DTV 2-way SWM splitter in place of the usual Holland or other brand Diplexer. I also noticed that he had connected the Sat. cable to the In port and the Receiver cable to the "dc power pass" out port of the splitter. (the opposite of what would be done using a diplexer) At the time, I didn't think to reverse the connections on the SWM splitter to check.
> 
> I replaced the SWM splitter with a correctly installed diplexer and all was good. Question, I know there are differences but are DTV 2-way SWM splitters essentially the same as a diplexor?


This is just a guess on my part having used both in my installation. The diplexer isolates out the OTA frequency bands to a separate output whereas the SWM splitters send all signals to all outputs while reserving one to pass LNB instruction (power path) back upline. Also SWM splitters allow 2 way signal traffic (DECA).

So unless my country bumpkin observations are all wrong, they are not the same.

Don "free advice is worth the price maybe" Bolton


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## samrs (May 30, 2004)

lugnutathome said:


> This is just a guess on my part having used both in my installation. The diplexer isolates out the OTA frequency bands to a separate output whereas the SWM splitters send all signals to all outputs while reserving one to pass LNB instruction (power path) back upline. Also SWM splitters allow 2 way signal traffic (DECA).
> 
> So unless my country bumpkin observations are all wrong, they are not the same.
> 
> Don "free advice is worth the price maybe" Bolton


I ain't nit pick'n or nuthin cuz but ifn I put the power supply on a separate line with a terminator and the IRD's on separate lines to the other ports wheres them "LNB Instructions" coming from?

*Question, I know there are differences but are DTV 2-way SWM splitters essentially the same as a diplexor? *

Diplexers pass power in both directions most splitters don't.

Like Mr Bolton stated Diplexers "filter" the frequencies something like 5-850 MHz on the TV side and 950 to 2100MHz on the sat side.

SWiM splitters pass somewhere around 2.5 to 3000MHz across the board.

sam "I just had to ask" rs


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## yogi (Feb 8, 2006)

I'd be a thinkin' that your just foolin with lugnutathome. But the communication channel or "LNB instruction" is between the SWM and IRD.


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## lugnutathome (Apr 13, 2009)

yogi said:


> I'd be a thinkin' that your just foolin with lugnutathome. But the communication channel or "LNB instruction" is between the SWM and IRD.


Yup. and in them old days the IRD directed the polarity of the LNB for proper reception but as I understand SWM they seem to operate as a polarity locker which is odd as I have a polarity locker in my stack between the dish and the cascaded SWMs.

Don "Mongo think it all magics and voodoo" Bolton


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## samrs (May 30, 2004)

Most likely just a 771B error what with ins and outs.

sam "just reads pictures" rs


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## VDP07 (Feb 22, 2006)

I think I's jus gonna break out that there SWM splitter next time I needs a Diplexer and sees what heppens...


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