IR Interference Between Floors

[davidbooker]

I've had lots of greatly appreciated help programming my URC 7562's from this forum .

Now I have a new problem. We have upgraded our main television (in the lounge) from a Philips plasma to a Samsung LED. We have a small Samsung in the bedroom, and this now responds to signals from the lounge, but not vice-versa! This is paradoxical, not only because I thought IR was a line of sight medium, and should not penetrate two brick walls and a ceiling, but also why should it travel only upstairs?

Is it possible in some way to attenuate the signal from the 7562 (the Samsung remote exhibits the same problem), and has anybody else experienced this phenomenon?

Many thanks.

[eferz]

Now I have a new problem. We have upgraded our main television (in the lounge) from a Philips plasma to a Samsung LED. We have a small Samsung in the bedroom, and this now responds to signals from the lounge, but not vice-versa! This is paradoxical, not only because I thought IR was a line of sight medium, and should not penetrate two brick walls and a ceiling, but also why should it travel only upstairs?

It sounds more like there's an RF to IR repeater pair involved. Most likely with the receiving unit in the lounge and transmitting unit in the bedroom. That's probably why it only works one way. Either that, or you have ghosts haunting you and are playing a practical joke.

I gotta say, if have InfraRed (IR) light signals that can penetrate brick then you probably have more to worry about than a television responding in the another room, Mr. Bruce Banner. Please don't get mad, I wouldn't like it when you're angry.

[vickyg2003]

You are right, IR doesn't travel through walls but it isn't necessarily "line of sight" either. I didn't see any mention of a base station in the urc-7562 manual, so I don't think this is an RF remote, and I didn't see any mention of an RF repeater in play to control one device from another room so that rules out an RF signal being sent to a repeater in the bedroom.

So the only other thing that I can think of is reflection. Think of it as a billards shot. Is there a single bounce reflection off a mirror or nice smooth wall or a darkened window that could be reaching the upstairs bedroom, when the remote causing the problem is being used?

[eferz]

So the only other thing that I can think of is reflection. Think of it as a billards shot. Is there a single bounce reflection off a mirror or nice smooth wall or a darkened window that could be reaching the upstairs bedroom, when the remote causing the problem is being used?

One way to rule out the Minnesota Fats effect, is to shut the bedroom door. I'm more likely to believe there's repeater in the mix, as the whole reflection on several structures is possible but not probable. Light can only bounce off so many times before the energy dissipates. Think of how strong a flashlight would need to be in order to be in order to travel that same path. But, then again... who knows, maybe he lives in the House of Mirrors.

I didn't see any mention of a base station in the urc-7562 manual, so I don't think this is an RF remote, and I didn't see any mention of an RF repeater in play to control one device from another room so that rules out an RF signal being sent to a repeater in the bedroom.

Besides, just because he didn't mention that was a repeater doesn't mean that he knows or remembers that one exists. Maybe his kids (or a ghost) is playing a practical joke with a Logitech Harmony IR repeater.

[vickyg2003]

So the only other thing that I can think of is reflection. Think of it as a billards shot. Is there a single bounce reflection off a mirror or nice smooth wall or a darkened window that could be reaching the upstairs bedroom, when the remote causing the problem is being used?

One way to rule out the Minnesota Fats effect, is to shut the bedroom door. I'm more likely to believe there's repeater in the mix, as the whole reflection on several structures is possible but not probable. Light can only bounce off so many times before the energy dissipates. Think of how strong a flashlight would need to be in order to be in order to travel that same path. But, then again... who knows, maybe he lives in the House of Mirrors.

Well there was a decorating phase in the 80's where mirrors were heavily used to make spaces look bigger. I'm trying to envision dual brick walls in the interior, and open lofts with large reflective two story windows come to mind. I think I watch too much HGTV.

However a forgotten IR repeater could well be the culprit.

[davidbooker]

Thanks everybody.

You are absolutely right, I have an RF videosender (5.8GHz) transmitting from the bedroom, and disconnecting the lounge receiver's IR eye has completely solved the problem. Very curious. I could change the videosender's RF channel, but would this affect the IR problem? In the bedroom the IR talks to the Sky+ box, and is mounted under the Samsung telly, out of its line of sight. Shouldn't half an inch of chipboard be enough to stop the IR signal?

All very odd! I'll try more shielding round the bedroom IR eye, and see what happens.

[eferz]

I could change the videosender's RF channel, but would this affect the IR problem?

No, those IR repeaters tend to be promiscuous. That would be like making a hooker speak a different language and not expect her to do her "duty".

In the bedroom the IR talks to the Sky+ box, and is mounted under the Samsung telly, out of its line of sight. Shouldn't half an inch of chipboard be enough to stop the IR signal?

This is where the Minnesota Fats effect becomes more relevant.

I'll try more shielding round the bedroom IR eye, and see what happens.

If you can segregate the IR blaster in the bedroom so that it can only communicate with the Sky box that would be your best bet. However, that might entail that you place it directly up against the Sky box's IR sensor and shielding the rest of the IR blaster's output.

[eferz]

Well there was a decorating phase in the 80's where mirrors were heavily used to make spaces look bigger.

OMG, do you remember those hideous mirrored panels with those obtuse patterns imprinted on them, and those tacky Patrick Nagel prints? There are somethings that I miss about the 80's and others that's hard to forget.

I'm trying to envision dual brick walls in the interior, and open lofts with large reflective two story windows come to mind. I think I watch too much HGTV.

I love that you have a creative imagination. I was hoping for something less common; like ghosts, gamma rays, and gremlins. Even the House of Mirrors would have been fun to troubleshoot!

[The Robman]

One way to rule out the Minnesota Fats effect...

I've never heard of the "Minnesota Fats effect", are likening the IR light bouncing all over the place to a pool ball doing the same thing?

[eferz]

One way to rule out the Minnesota Fats effect...

I've never heard of the "Minnesota Fats effect", are likening the IR light bouncing all over the place to a pool ball doing the same thing?

Heh, heh. Yes, I just coined the phrased after Vicky's analogy.

[The Robman]

The phrase may well stick!