Thursday, May 15, 2014

IR over coax to emitters in multiple rooms

When playing FM tuners in the living room elsewhere in the house (through Sonos…that's one of the best features of Sonos is the ability to play sources in other rooms) it would be nice to have remote control over those tuners.  Several of my top tuners have Infrared (IR) remote control (Yamaha TX-1000, Kenwood KT-6040, Kenwood L-1000T).

I've tried this before…many times over the years.  It's been hard, very hard, with Radio Shack Remote Extenders (which have great difficulty sending signals more than 20 feet in my house).   The master bedroom to living room is the longest stretch, about 35 feet, and the Radio Shack extenders can't go that far (despite relative lack of big metal stuff in the way).  So long ago, I cut one of the LED wires and spliced in a 75 foot zip cord which still runs from the living room stereo all the way to the Radio Shack "Receiver" (using Radio Shack terminology, that means the device which receives the RF signal and emits IR, or allows you to attach an LED on a wire to emit the IR) in the Kitchen.  That specially located Receiver in the kitchen picks up the Transmitter in the master bedroom very well, especially now that I (many years ago also) attached a big external antenna to it (which is connected straight to the PC board inside the Receiver) mounted inside a kitchen cabinet.  Then I found that attaching this big wire degraded the direct IR output so much it couldn't control all the video components in the kitchen anymore.  AND, it didn't do a good job of getting the IR into the living room either.  This was going to be the big "solution", but after I did all the work I found it didn't work.  (It had seemed to work in mockup.)

And that's only one little story out of 100's in my long standing efforts to get the Radio Shack Remote Extenders to work as advertised.  If they actually did work as advertised (100 foot range or whatever it is they claim), I could control equipment in all different rooms in my house from any one room in the house.  That's "many to many", a kind of holy grail in home A/V distribution.  But I've never gotten to do so in more than 2 rooms at a time, and never the living room.  The problem appears to be that all these systems (not just Radio Shack, but all the RF remote extenders) are limited to a paltry 10dBm at around 400mHz, which barely rises above the RFI in my house.  I see now there's one with the same 10dBm which claims 325 foot range.  (I'm tempted to try it anyway, but I've already tried about 10 such systems, and they all work poorly, despite what friends and other say.)

I should have gone to a more "professional" IR distribution system long before all this.  But now I'm finding out that isn't necessarily easy either.  Even though now I have all rooms professionally wired with many different kinds of wire (as of last July), and I have currently unused coax running to all rooms.  Many IR distribution systems run on coax.  So I should be set, right?  Now it turns out that most such systems are only designed to emit IR in one room only.  Here's message I just posted to AVSForum (which has a Remote Control Area):

For IR over coax, I've looked at Xantech, ChannelVision, Channel Plus, and others. None of them show complicated systems, usually the the most simple system possible or close to it. The older Xantech manuals (not the latest ones) show reasonably complex setups, with IR receivers (targets, etc) in multiple rooms. But nobody shows LED emitters in multiple rooms. That's what I need. One recent Xantech manual I've seen has a disclaimer at the bottom that systems more complicated than those shown require professional installation. Question: how much would that cost? I already have spare (currently unused) coax running to all rooms. I worry that professionals wouldn't be interested in just adding IR to my existing system, I would think they like to do whole systems from the ground up because that makes them more money.

Xantech seems to have some of the best quality hardware for IR in general, and since I already have some of their stuff I'd like to stick with Xantech if possible. For coax distribution they make the INJ94 injector and CPL94 coupler (which permits the direct attachment of 4 LED's in 2 strings). It looks like you can have as many INJ94 injectors in a coax network as you'd like, as they each work independently. But nowhere in any Xantech documentation have I seen it say how many CPL94's you can have on the same coax. I'd suspect the answer is: only 1. Now you can have more than 4 LED's, but only if you have CPL10 (a therefore essential part that Xantech seems to be discontinuing) attached to a connection block, and the standard connection block can take 8 LED's (in 4 strings) and you can get amplified connection blocks that handle more.

Given what I know, I wonder if 2 CPL10's on the coax network would work better than 2 CPL94's. I'm thinking a CPL10 might put less load on the line (or injector) than the CPL94. But it's exactly this sort of information which is not available.

My current system needs emitters in two rooms, one room with 4 LED's and another with 8 LED's. I can imagine a future system might need emitters in a 3rd room as well. 4 rooms need receivers as well, but that part is well documented. This is many to many whole house system. Video is already handled with HDMI over Cat6 with a 4x4 switch, and audio is handled through Sonos. What I need to control in non-central rooms is mainly additional audio sources run through Sonos.

Another question: can IR over coax co-exist with composite video, or does video need to be modulated into a vhf/uhf channel?

No comments:

Post a Comment