Frustration with X10 Powermid

I've had X10 Powermids for IR remote control extenions for years, and I'm about fed up. I think its well known that they are very sensitive to their environment, and easily transmit spurious output. The LED on my transmitter varries from showing a very dim pulsating background signal, to an almost continuous bright solid. In the former case it still can function normally with most but not all devices. I can usually get rid of the solid bright by some repositioning, but the dim pulsating occurs even with no receiver plugged in.

Is there some substitute that is rock solid?

Reply to
km
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Reply to
Dave Houston

NO fluorescents and NO sunlight in the area. There is plenty of other electronics though (DVR's, wireless lan, etc). I stipulate its a noisy RF area, which is why I'm looking for something more resistant then X10.

Reply to
km

If you can run wires or have existing coax between locations then you can use Xantech parts to build a IR repeater system. The advantage to this will be that your existing remote(s) will work the way they are supposed to with the Powermids. Depending on the system the cost starts at around $70.

If you have to go wireless there are some One For All remotes that send RF from the remote to a receiver where it is output as IR. The URC-9910 is one such unit:

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This is a very popular item (read that as out of stock) and is likely your least expensive option. If you look around they can be found. Using a JP-1 cable they can be programmed to handle almost anything. The advantage of doing this that you can replace a table full of remotes with a single INEXPENSIVE unit. The downside is that it can take a bit of work and learning to get the remote to work the way you want it to work. I use a Xantech IR repeater system with IR only URC-7800 remotes and everybody in the house is happy.

Some high end remotes offer RF extenders. Here are some links:

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Here are some good links for IR remote info:

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Reply to
Lewis Gardner

Are the units on top of a TV or a monitor? The Powermids I have don't like sitting on top of the TV. You can see the LED get brighter and brighter as you move the Powermid towards the TV set, even if the room's pitch black. Some sort of inductive coupling, it seems.

-- Bobby G.

Reply to
Robert Green

The Powermids use 418MHz RF which is by and large unused except by other remote extender devices like the Powermid. The IR receiver has a grounded metallic shroud. RF interference is one of the least likely explanations except for strong local sources near the 38kHz IR carrier frequency. A nearby TV (as Bobby Green suggested) is one possible source - harmonics from its horizontal sweep are the source.

There's a whitepaper from Vishay that lists some possible IR noise sources.

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This >NO fluorescents and NO sunlight in the area. There is plenty of other

Reply to
Dave Houston

I went and did an experiment to eliminate all the factors I could.

I cut off all the power to my apartment at the fusebox. I have a UPS and unplugged everything from it except the Powermid transmitter. This was in a dark room with no window.

I still see the led blinking in the transmitter. I actually repeated this with three different transmitters an old radioshack, a new radioshack, and an X10 branded one. Same result.. I also tried the experiment in other rooms, still same result.

I don't see what else I can change, except look for a more discriminating hardware solution.

Reply to
km

That would appear to eliminate any EMI originating from within your apartment.

Does a neigbor have a plasma display? While Powermids have a fairly good reputati>I went and did an experiment to eliminate all the factors I could. >

Reply to
Dave Houston

Hello Dave,

No idea how selective their RF filter is but the ham radio band of

430-440MHz is close by. If there is an active ham or a repeater in the area it might interfere. Then there is the ISM frequency at 433.92MHz which is used by all kinds of stuff such as remote thermometers.

On 418MHz there is some other usage as well. Wireless alarm systems, garage door openers. While the transmissions are intermittent and usually brief some cheaper systems might use those dreaded "super-regenerative" receivers. Some of those are constantly spewing RF.

Then there are the "modern" switcher supplies. Today almost anything has these. Laptops, printers, video games, fax machines, LV halogen lights and so on. Often they try to get away with the least amount of RFI protection that makes them barely pass. On some of them I wonder whether they ever passed.

Regards, Joerg

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Reply to
Joerg

I have done some new experiments.

I decided to take the Powermid transmitter outside my apartment, and found that the LED glowed even brighter outside. I then drove it a few miles in each direction and got the same results consistantly. In my car I used an AC inverter to power it, but I also just plugged it into AC at various outdoor power sockets. The results were very consistant.

I took it over to a nearby office building and tried it at various points in the building. In the interior the LED was dark, but at points near the exterior or near windows it glowed.

In my aprartment there is no spot where the LED stays dark. It's a brick building constructed in the 1950's, which I presume has walls that provide less shielding than the the new office building.

I don't know if there is something special in my area transmitting at

418mhz, or if this is typical. My guess is that it's not that unusual, and that most people have better shielding. Even in my apartment the background LED glow does not cripple operation with most of my IR devices. I started into this because just one of my IR controlled devices would not work either through the Powermid, or even directly when the Powermid transmitter was on. Most of the others work but are intermittent at times.

Probably an unlucky device, poor shielding in the walls, and an unknown RF source painting the neighborhood.

I have tried a Terk a year back which operates at 433mhz and it was similarly balky. It was a short test, and at the time I didn't test for background glow outdoors. Either that background is over the whole

418-433 range, or these devices are not real discriminating by frequency.

I was going to try a URC-9910, but I see its also at 433 which is discouraging. (Also they seem to be in very short supply).

I really seem to be stuck. I wish someone would make an 802.11 device. That would allow generating the IR sequence from a laptop/pda as well as from a matched 802.11 repeater, and also work more reliably.

Reply to
km

Unless I am having a major brain fart all you are proving is that the IR sensor is very prone to interference. If you want to test for RF interference you would use the receiver without any valid Powermid transmissions in the area and see if it emitted IR.

This IR sensor is the major problem with the Powermids. I quit using them years ago because they considered everything on planet earth to be a signal worth repeating. IMHO they are junk.

I believe that your problem is likely the crappy IR of the Powermids not RF interference. The URC-9910 is under $50 and would likely be a improvement over the Powermids.

What is wrong with wire? Don't you have a coax between the viewing location (where the remote is) and the equipment location? Is running a wire between the two impossible? Wired IR repeater systems are more reliable than wireless.

802.11 will cost considerably more than a wired system.
Reply to
Lewis Gardner

What part of "you need to keep the transmitter away from fluorescents and direct sunlight" confused you? Your own statement, "In the interior the LED was dark, but at points near the exterior or near windows it glowed." should tell you something.

The Powermid system has two components, one receives IR (with carrier modulation in the 38kHz ±5kHz range) and retransmits it as 418MHz RF. The other receives 418MHz and retransmits it as IR (with a carrier in the

38-40kHz range). Both work in real time with no delays other than the response times of their receivers and transmitters.

The one without the antenna is the IR-in/RF-out (transmitter) and the other is the RF-in/IR-out (receiver). The receiver has an antenna for receiving RF.

If the transmitter unit was sensitive to 418MHz RF, it would interfere with itself so it is unlikely that your problems stem from RF in the 418MHz band. It is even less likely to be RF interference from the highly used bands above 430MHz.

When the transmitter LED is glowing, the unit is either receiving IR or EMI (electro magnetic interference) in the 38kHz ±5kHz range or sunlight (which has a lot of IR). You can verify this by taking the transmitter unit to a darkened room, pointing an IR remote at it and pressing a button on the remote. The LED will flicker on and off as the unit receives the IR. If you have any RF remotes that use 418MHz, you can also verify that the LED (on the transmitter) does not flicker when you press a button on the RF remote but that the one on the receiver (with the antenna) does.

Aside from sensitivity to sunlight and EMI the Powermids work well. Aside from sensitivity to sunlight and EMI most other remote extenders work almost as well - many of them are merely Powermids in cognito which you can verify by checking the FCC ID number (B4SST539) on the unit with the RF transmitter.

While it's not an 802.11B device, the Global Caché GC-100 can be c>I have done some new experiments.

Reply to
Dave Houston

I wouldn't expect the Powermids to work in bright sunlight. All of mine are located away from both sunlight, CFL light and known EMI generators such as TV sets.

I would suggest putting one inside of a metal box or can to block out as much RF as possible just to test to make sure you don't have a defective unit and to see whether your area is saturated with EMI that affects the unit. As someone else noted, you may be located near a ham radio station or some other source of interference. Based on the experiments you've run, that seems to be very likely.

As I said, I've taken great pains to shield my units from direct and even strong indirect sunlight. They just can't handle it.

It's hard to say.

The fact that the device doesn't work directly with the Powermid on is bad - it certainly was the problem that made me put each Powermid on a separate appliance module so that I could turn on only the one I needed and could leave the others turned off. IME, it seemed that the problems multiplied when all the Powermids were transmitting, even though only one of them was actually sending commands. I also have to keep them ALL turned off when I am controlling devices locally in the AV room. That means that mine are receiving and repeating junk that interferes with the real IR signals.

It would be nice to figure out which!

Do you have an X-10 RF gear? Is it similarly balky? I found that when I had a continuously transmitting Palmpad it knocked out the Powermid closest to it, but left the others operating as normal.

I think Mr. Gardener's advice is probably the best solution for you - go hardwired. I would expect that solution to be far less troublesome but there's a remote chance that whatever's plaguing your Powermids could also bother hardwired IR sensors. If you buy hardwired gear, buy from someone who'll accept returns just to be sure.

-- Bobby G.

Reply to
Robert Green

Thanks for all the responses, but I think I need to clarify some things.

First of all my recent tests were ONLY with the Powermid transmitter plugged in. The transmitter is the one with the antenna that receives RF and outputs IR. As far as I know there is no IR receiver in this unit.

I assume the glow on the LED in this unit reflects how much RF it has detected and how much IR it is transmitting.

All my tests were done at night, no sunlight inside or outside. All outside tests over a several mile range showed a brightly pulsating LED, as did all locations in my apartment. This included tests in my apartment with all power cut off at the fusebox, and only the one powermid transmitter plugged into the UPS.

The tests in the office building were also at night. The building has all fluorescents. No glow in the interior of the building despite the fluorescents. Pulsating glow near the windows and entrances.

As far as using a wired repeater, that would be awkward. I have receivers in 4 different rooms. Just so that there is no confusion, my tests were done with none of the receivers plugged in.

I would like to try the URC-9910. Can anyone suggest a good place to buy one, where I can return it if it has the same issue? None of the big box stores seem to carry it, and froogle seems to only turn up noname sites with no stock.

Reply to
km

NO, it is not. That is the receiver. See...

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The transmitter receives the infrared (IR) signals from your remote control and converts them into a radio frequency signal. This signal penetrates walls and is picked up by the Receiver. The receiver then converts the signal back into an IR signal and sends the command to the equipment being controlled.

Given that they invented the Powermid I would suggest following their description of which is transmitter and which is receiver instead of creating your own mistaken terminology.

The LED in the unit with the antenna lights (the receiver) when the unit _RECEIVES_ 418MHz RF.

RF would not be present only near windows and entrances.

What you describe has near zero probability. Either you live in a parallel universe where the laws of physics do not apply or your Powermid RECEIVER is defective.

This totally contradicts everything else you've said.

If your region of the country is truly flooded with continuous 418MHz RF, then you will likely have the same problem with almost _any_ other RF extender. Nearly all of those sold in North America use 418MHz although the URC-9910 does use 430MHz and there are a few that use 433.92MHz.

Given that you have multiple Powermid transmitters it would make more sense to try another receiver - whether another Powermid or another brand (e.g. Terk LF-IRX) that also uses 418MHz. Otherwise you will need multiple URC-9910s.

Reply to
Dave Houston

Yes, It turns out I'm using the terms receiver and transmitter backwards from the manufacturer. I thought of them from the standpoint of transmitting/receiving IR, while they are labeled by whether they transmit/receive RF. I'll be careful to use the terms correctly in the future.

I can only report what I see. I do have two other receivers (which are normally not used). I will repeat the outdoor and office tests with them. In my apartment they all exhbit the same problem.

I did try the Terk a couple of years ago, and it worked less well than the Powermid. I didn't do extensive testing at the time.

Right now I have a universal remote in each room that has a powermid transmitter. It would be less convenient, but I could just carry the one urc-9910 remote from room to room, if it actually worked better.

Reply to
km

Are the areas where you have tested near a military base?

It's very common to see reports of the LED flickering on the IR->RF (transmitter) unit due to the reasons cited earlier. It is not common to see reports like yours. I dug my Powermid pair out to test and the transmitter LED flickers almost constantly if the room sees sunlight but the LED in RF->IR (receiver) unit only illuminates when 418MHz RF is present. I also tested using a 433.92MHz RF transmitter in close proximity and the receiver LED never flickered.

It's difficult to imagine what could be transmitting a continuous 418MHz signal that you would see in all of the locations where you tested. I would expect there would be complaints from others if the entire area is saturated with 418MHz RF.

If your other receivers also >>NO, it is not. That is the receiver. See...

Reply to
Dave Houston

If you still suspect RF noise pickup there is an easy test that works well at VHF/UHF frequencies such as 418MHz. Borrow an emergency backup pack that has a battery and inverter in a box the size of a six-pack. Campers often have these. Also owners of newer wood stoves like us, to keep the little fans running when the power goes. Now place that and your RF receiver unit inside a (clean...) metal pail. Then press chicken wire mesh over the top and see if the LED still blinks. If it does I'd suspect the unit could have a defect.

Regards, Joerg

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Reply to
Joerg

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