Strange IR emitter problem

Ok, I have a Xantech IR receiver by my television. It has the supplied IR emitters to a cabinet where the stereo, DVD and HD-directivo are located. Ok, the Xantch delivers the IR signals just fine to everything except the stereo. I've replaced the Xantech receiver and the emitter. Still, everything but the stereo can be controlled. Changing the location of the IR emitter didn't help.

I then tried replacing the Xantech with an X10 powermid. Now everything works. The problem? The X10 powermid blocks the UHF remote for my old timey C-band satellite dish. Argh.

Any ideas on what could cause this kind of behavior?

TIA, Dave

Reply to
Dave Leon
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You don't mention make/model of the devices. Hard to answer technical questions like this without details....

Reply to
Bill Kearney

Sorry about that. The Xantech unit is a 291. The IR emitters were no-name guys that came with the unit.

The receiver is a Yamaha HTR-5890. This unit worked fine with the existing setup for a number of years. I changed nothing when it stopped responding to the Xantech system. Replacing the Xantech IR receiver and IR emitters changed nothing. Neither did moving the position of the IR emitters.

All other components work just fine with either Xantech and with both sets of emitters. Also, the universal remote works just fine if I point it at the Yamaha receiver directly.

The universal remote is a TiVo remote.

Reply to
Dave Leon

Something has to have changed.

The most common problems I have found with IR repeaters are:

  1. The controlled device "sees" both the IR from the remote and the flasher. This causes the IR signal to get scrambled. The Xantech MS-1 or aluminum foil can help with this problem.

  1. The IR flasher is too bright for the IR receiver on the controlled device. Moving the flasher away from the IR pickup on the controlled device or attenuating the flasher with various materials can help with this.

  2. Unwanted signals are getting into the repeater system and distorting the signal. Make sure the talkback LED on the IR receiver is not flickering when no IR remote signal is present. If changing the placement of the IR receiver cannot solve this problem then the 291-80 CFL friendly receiver is your next step.

If none of these fix the problem then you may have a problem in the IR section of the Yamaha receiver. I had a ReplayTV unit that worked fine with a remote but not with a repeater, just like your problem. The fix was to "hotwire" the IR into the unit. Experience with a soldering iron and scope are handy with this sort of modification.

Best of luck.

Reply to
Lewis Gardner

Lewis,

How much of a problem do CFLs create for IR receivers? Is the interference filtering on the +12V or in the IR circuits? IOW, do the CFLs emit high level IR in the frequency range typically used by remotes or is it just the conducted noise that's also a problem for powerline carriers that's an issue. I can see how filtering the +12V can be done but not how any filtering can tell spurious IR emissions from legitimate ones.

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Reply to
Dave Houston

Haven't given much research to the cause of the problem.

During installs I put a Xantech 291-10 in place first and if it works fine. If not I replace it with a Xantech 291-80 and in most cases the problem goes away. Usually the 291-10 will exhibit flashing of the talkback LED and the 291-80 won't. In many cases there are no CFLs in the vicinity.

I would assume it is not a power supply issue since the same power supply works in either case.

I would use the 291-80 exclusively but 291-10s keep finding their way into my IR install box. The 291-80s are about $20 more but save a bunch of frustration. Here is the PDF:

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Overall I have found Xantech stuff to be quite reliable and well worth the money. Other that the issues listed in my last reply the only other problems I have found are:

  1. The power supply needs to be 12 volts. Regulated supplies required. Currently I am using CUI part number DPS120100UPS-P5P-SZ switch mode power supplies from Digikey. They are small and usually take only one outlet space. On review I may get some EPS120050-P5P units since 500 mA is more than enough for a small system and they cost about 1/3 of the 1 amp units.
  2. Mis wiring. I recall a problem where the ground and signal wires (I think...) were reversed and while the talkback LED flashed IR communication was flaky at best.

Other than these 5 issues (common to all repeater systems) I have only had 1 normal piece of equipment that could not be reliably controlled with a repeater system. Of course this is normal equipment. Some high end stuff like B&O use a very high carrier frequency and need special stuff.

Reply to
Lewis Gardner

Thanks for the PDF link.

Fluorescent lights have always emitted IR light and many IR receivers are bothered by strong RF emissions (e.g. from a plasma screen or nearby TV) so I'd be surprised if they are using "CFL friendly" in reference to those. Conducted noise could still be an issue - it might be that the 291-80 merely has better internal filtering on the +12V. It might be interesting to see if a standard unit would work in the same environment when powered from a battery.

I have no need of and thus no experience with Xantech but I haven't seen many complaints so your views seem to be the consensus.

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Reply to
Dave Houston

Legacy (i.e, not CFL) fluorescent lamps are particularly suspect. Modern CFLs can avoid the problems demonstrated by legacy, conventional fluorescent (not CFL) ballasts.

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CFLs have benefited from the research on interference mechanisms and frequencies and some recent ones have purposely have avoided the design pitfalls that still affect older fluorescent ballast designs. Hence more "IR-friendly" CFL designs.

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ends with the words:

"Many consumer IR systems, such as commonly employed in the TV and audio industries, utilize the 33 to 40 kHz region for IR carrier frequencies. [...] Many CFL high frequency electronic systems have already vacated this frequency range, but this may not be feasible for linear fluorescent high frequency ballasts.."

... Marc

Marc_F_Hult

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Reply to
Marc_F_Hult

And IR remotes have 'always' been susceptible to interference from some conventional and compact fluorescent lamps as I cited in my previous post in this thread.

See the National Electrical Manufacturers Association (NEMA) technical docs from 1998-1999 referenced in my previous post and these IEEE docs:

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?arnumber=469093
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?isnumber=11527&prod=CNF&arnumber=530565&arSt=2066&ared=2068+vol.3&arAuthor=Anderson%2C+W.A.%3B+Hammer%2C+E.E.%3B+Seres%2C+A. So whether or not Dave is surprised, this is indeed what Xantech appears to be referring to.

From

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" Use when LCD Displays or direct sunlight / compact fluorescent lights are present. LCD displays emit light wavelengths that interfere with IR carrier frequencies. Xantech?s exclusive adjustable frequency range eliminates this problem."

... Marc Marc_F_Hult

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Reply to
Marc_F_Hult

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