That was a year ago, so the specifics escape me, but I think I had small rack with two Denon AVRs, Sat, and in remote locations the two displays and a Sat receiver.
In the end, I upgraded client to a serial controlled RFX9600 and that did it.

Sorry to bump this rather old thread, but I figure it is better to continue the same thread than to start a new one about the same topic since I have a specific question about what is stated here.

Based on the above, it seems clear that a totally passive device that simply parallels the signal like a mono Y adapter isn't going to be a reliable solution for splitting an IR output. What about using an RF splitter?

I successfully split an IR signal coming from a Globalcache IP2IR device (using a mono to F81 adapter to put the signal on RG6) using a Skywalker 22303 splitter, which passes DC on both ports.  Would the transformer used in an RF splitter that the signal must pass through avoid the issue with paralleling two LED emitters?

It may not - perhaps the DC and low frequency IR signals are not going through the transformer.  The DC/baseband signals may be paralleled inside the splitter, and only the higher frequency RF signals in the advertised 5-900MHz range go through the transformer?  I don't really know the difference internally between a DC passing and DC blocking splitter.  Anyone know?

I realize this wouldn't be a worthwhile solution for those who aren't already running IR over coax.  I am, and being able to double up some of the ports would be nice, but only if using a splitter avoids the parallel LED voltage issue Ernie explained.

Yes, and bless you for not just adding some detail about how THAT system would have been connected in 1998....


Right on the first point. An RF splitter takes the POWER coming into it (voltage at 75 ohms) and splits it into two signals of equal power, which in a perfect world would be 3 dB down from the input. To do that, as few losses as possible are allowable... and remember that RF is really high in frequency compared to IR, so IR looks more or less like DC to the average splitter. So, too late to make a long story short, an RF splitter might happen to split an IR signal, but the resistor that would guarantee power sharing in an IR splitter would ruin the RF performance. So the RF splitter is no better than a Y connector for this.


No, as I said in my last paragraph, at DC the outputs are basically in parallel.


You're overthinking and undermeasuring this. And not all splitters are made the same. You can't make any assumptions, so the best route is not to use a splitter.


Or for those who are running DC over coax, meaning ANY satellite signal, with the possible exception of the latest whole house networks. Those are so new that I haven't had the time to play with any of them; however, the systems in which they are installed generally call for RF remotes so I don't need to run IR for long distances.


I may have missed a point here, but you could split the IR off the RF; run it throught a Xantech distribution block; then mix it back into the RF. This would be done with four parts: The Xantech part that splits IR from RF; a 789-44 or DB-20; and to of the Xantech parts that mix IR with RF. This hardly seems worth it for a real system, though it might be educational.

Thank you very much for that detailed explanation. Guess there is no shortcut around buying enough devices to provide me the proper amount of IR outputs.

As for getting IR to/from coax, I've found those Xantech parts are not necessary. I am using 3.5mm mono to F-81 female F type connectors to get the IR signal to coax, then using a satellite diplexer to mix the IR signal with the RF signal. Then the same in reverse on the other end.

That is all a Xantech CPL10 is doing internally, but my solution costs 1/4 as much and allows for a much neater install in my environment. I'll have over two dozen such connections, by putting the mono to F-81 adapters in keystones I can use a keystone rack panel for the interconnections rather than having CPL10s dangling off the coaxes.

 I have had success splitting ir using niles emitters in parallel. But i did not have success using urc emitters in parallel.  It may have somthing to do with urc emitters actually lighting up when in use.

that said, i prefer to use xantech dual head emitters when i need to connect two emitters to a port.

If your RF is not going in the satellite input, then I'm guessing you're not talking a bout satellite RF. You never mentioned, but I'm guessing you're talking about cable signals. If that's the case, this works totally because the satellite side of a satellite diplexer is designed to combine or separate (it doesn't care) DC and the signal going through the RF section.

It's definitely the way to do this.

If the client ever decides to change to satellite, he is totally f*ked. I prefer to install in such a way as to allow for other technologies that are now available.



Maybe. But one thing that definitely makes only one of a pair work is that one turning on at a slightly lower voltage than the other one. I don't know if that comes into play here.

Let me point out, too, that you might split IRs with Y cables all your career and never have a problem. In doing so you are depending on the manufacturers to supply LEDs that turn on at exactly the same voltage, something they do not try to do. Just as the idiot driving 120 mph in traffic is depending on everyone he passes not to make a stupid move, you'd be depending on exact duplication of a spec that is not carefully controlled.


Me too. They are two emitters in series and thus work a tiny bit differently -- for sure, parallel this with a single LED without a resistor and it won't come on!

You're correct, but in this case there are separate cable runs to each TV, one for satellite and one for OTA, with the IR being run over the latter. So no issues in the future with the RF frequencies or DC voltages using my diplexer solution.

Only fairly old and out of date Directv installs will be carrying voltage from the receivers, the newer SWM technology does away with that legacy voltage signalling. Directv's newest receivers and DVRs (H25, Genie and Genie clients) support only SWM, you can't even use them on a legacy install. I'm unfamiliar with Dish Network technology, so I can't speak to the situation there.

So long as you're using SWM my solution will work over the coax carrying the satellite signal to the receiver, simply substitute one port DC passing satellite splitters for the diplexers in my previous post. I have not tested this, but there is no reason it shouldn't work. You may need to get splitters designed for SWM - it uses 2.3 MHz signalling from the receiver back to the multiswitch/dish. Typical 5-2xxx MHz satellite splitters may attenuate the 2.3 MHz signal undesirably.

If you wanted a flexible solution that will work for coax carrying CATV/ANT or a possible future Directv install (and maybe Dish?) then the one port power passing splitters would be the way to go. They'll cost a few db in signal, as does any splitter, but that should not present a problem unless the S/N ratio was already on shaky ground.

True. That's why my signature. If you had said that, I would have responded differently. Meanwhile, until you pointed that out, anyone else following the details of this thread would be forewarned.


Yeah, and in 1994, I think, Qintar was about to close out its multiswitches because there was hardly any further use for them. When I told them that they would fall right into DirecTV installations and folks would no longer have to have two dishes to have four receivers, they started marketing to DirecTV installers. And you used to be able to diplex OTA with DirecTV signals. And so many other things that have changed. I think it might be true, but totally unwise, to say to someone that DC WILL NOT ever be carried on DirecTV wiring again. It's the nature of the world that things change in ways that you cannot predict. Look up remotecentral member Wesley Mullings.

edit: corrected "Mullens" to "Mullings."


You did not mean "until you stop using SWM," but that interpretation of your words is right on the money with my warning above.


That last phrase is most often described by the term "famous last words."


Do these exist? Can you get them? I was working on this idea some time ago and came to the conclusion that the product might not exist. Another idea I had -- I don't remember the details right now -- involved the UVSJ and a VHF Hi/lo diplexer.


Do you really mean splitter, or instead diplexer? Diplexers cause hardly any loss of signal but the perfect splitter guarantees 3 dB of loss, real world is 4 to 5 dB.

Yes, I meant splitter, that's why I was referring to signal loss if using a splitter in this way. Here's an example of a 1 port DC passing satellite splitter rated for 5 MHz and above:

[Link: summitsource.com]

Here's an example of the Directv model for SWM installs rated for 2 MHz:

[Link: summitsource.com]

The official Directv one is kind of pricey, in percentage terms, but the "green label" splitters must be used in a supported SWM install. Most likely any old satellite splitter rated for 5 MHz won't have any issues at 2.3 MHz, but you'd need an oscilloscope or something if you wanted to be sure. I've seen cable splitters rated at 900 MHz installed and working perfectly splitting Directv LNB signals that range from 250 - 2150 MHz. I have a feeling that in most cases a given company's cable splitter and satellite splitter are the exact same product with a different part number and different price :)