The reason the Cat-5 cabling worked for me is that I was able to move the antenna much farther away from the source of the interference -- my equipment rack. I also connected the unused lines in it to ground for some shielding, but really it was just a matter of moving the antenna farther away from my equipment.

That would suggest your interference was coming in via the RFX antenna itself. Getting the antenna away from whatever is emitting all the RF noise was your only choice, other than eliminating the noisy equipment. What you did was improve the S/N ratio; your interference was reduced in strength to a greater degree than your remote RF signal. Adding the CAT5 to connect the RFX unit added another measure of additional safety; it safeguarded your RFX cable from picking up the same noise.

I only have an MRF unit; the antenna is not detachable, so the only cabling I have is the power and IR emitter cables.

Every so often, my TV will turn on by "itself" or my Comcast cable box will switch channels or go to the DVR menu on its own. I suspected right from the get go I was picking up some kinds of commands that were messing with the gear. Would installing ferrite cores on the flashers solve this problem? I am also noticing the status light on the MRF to be constantly dancing, even when there are no commands being relayed.

What remote, base station, etc.

We need details to help.

Off the cuff, I'd say you have an mrf100 which isn't addressable and one of your neighbors has a simlar remote.

I agree with OEX.

Chances are some neighbor has an RF remote and it is picked up by your receiver. If that is the case, one of you needs to change the "address" of the remote & receiver. Hopefully you don't both have the same non-addressable units. I don't think ferrites will help you, since the unwanted signal is most likely picked up by your antenna. As a last resort, you need to reduce the gain of your antenna somehow (try some various tin foil shapes on/around the antenna. You can also try a different orientation or moving it around to different locations.

If your equipment is actually recognizing valid commands (changing channels, turning on/off by itself), it is highly unlikely to be random noise. One (or more) of your neighbors must have a similar TV and Comcast box AND they're using the same RF remote as you. OR, they have line-of-site into your TV room and their infrared remote signals are being picked up by your equipment. You can easily eliminate that possibility by blocking off your TV and comcast box IR sensors with tape or something, provided your own IR emitters still have good visibility to the sensors.

Interference can turn a command you're trying to send in to something unintended. If there is another MRF unit nearby, it will still interfere even if you change the channel. Changing the channel will help make sure that your MRF will ignore commands from a neighbor's URC remote but it won't stop interference if two people are operating a URC remote at the same time.

Somewhat off topic BUT

I would suggest EVERYONE try this. PRIOR to installing a base station. Put it in sniff mode and look around and try to find RF. You'll be shcoked what can cause it. Once you see that the recvr, DVD when on, DVR, video cables, plasma all cause RF, you can then AVOID mounting the antenna, running any wires or the base near such devices. This 5 minute exercise WILL save you hours of ass ache. Trust me.

Thanks for the assistance guys. I've got an MX-850 with the MRF-250 installed. I took the RF250 out of sniffer mode and set it to some different number (forget which one), and looped the 3 emitters through a ferrite core just to cover all my bases. I'm still getting the problem of my cable box going haywire with legitimate commands and my TV will still turn on by itself. It's frustrating because the TV will be on and wasting electricity when I'm not even home!

I'd like to avoid having to use an MRF-300, as I don't need many of the features and don't see the justification in spending the additional $$, but if that's what it takes to solve the problem, so be it.

Before I go switching out the base station, would removing the antenna from the MRF-250 prove worthwhile? I've got an apartment, so the range is 30 feet at max, and usually I'm in the room right in front of the equipment stack. I'm open to any and all suggestions from people's personal experiences. I'm a CE industry professional, but I've honestly never had this problem with any of my past or present clients.

It's at the point now where I actually UNPLUG the base station when I leave the house! This is getting out of hand!

On the Basic Ferrite Core discussion at large here, these are the brand that I use, purely because of the quality. This site also has some good general information on it.

http://www.ferrishield.com/

You can pick these up at Mouser Electronics:

[Link: mouser.com]

My system was installed by a "professional" installer, who I have since determined was kind of an amateur. I should have shopped for an installer myself, rather than allowing my general contractor to do it. But that's water under the bridge, and a way of explaining why I, a consumer, am now faced with fixing my system's problems, which I've been suffering with for a couple of years now.

I have an MX-850 which uses an RFX-150 to relay RF signals to a pair of MRF-250's.

Everything in my system is controlled by RF, except for the TV, which is IR. The component stack is in a bedroom closet, out of line-of-sight from the remote. The RFX-150 is positioned high in the bedroom closet, above the component stack.

Everything works fine, at all times, EXCEPT my ReplayTV 5500, which often, and randomly, fails to respond to the MX-850. It responds perfectly, however, to its own remote, if I walk into the closet and point it at the Replay, and responds perfectly to the MX-850 if I enable IR on the MX-850, and walk into the closet and point the MX-850 at it.

When the ReplayTV is failing to respond, its misbehavior can last for a minute, or an hour. Occasionally a command will get through to it; I have to press buttons on the remote repeatedly during these episodes to get a single command to register. Other times, it works just fine.

I did not at first think the problem was radio inteference, because all my other components work just fine; if it was radio interference, I figured, it would affect all the components equally.

Rather, since this doesn't happen with any of the other components in my system, I assumed it was a ReplayTV-specific problem (or a problem specifically with communicating with the ReplayTV). I tried many things: I replaced the circuit board in the ReplayTV that contains the infrared sensor. I adjusted, in both directions, the intensity of the signal being sent by the MRF through the IR-blaster to the Replay. (Maybe it's saturating? Maybe it's not strong enough? Maybe if I fed it wet instead of dry food?) I tried a different MRF unit. I tried a different IR blaster cable. I even tried a different MX-850 and a different RFX-150. I tried re-programming the codes into the MX-850, using the Replay's remote. I tried positioning the MRF unit in front of the component stack and using the built-in flashers, rather than the IR blasters. Nothing worked.

Having finally encountered this thread (and having run out of things to swap out), I am of course suspecting RF interference. (I feel like I've ruled out or swapped out everything else!) This would account for the total randomness of the occurrence of the problem...and I notice that (duh) the little RF indicator light on the RFX-150 flickers (dimly) from time to time when I'm not using the remote. (It lights very strongly, of course, when I *am* using the remote.)

I've turned the sensitivity of the RFX-150 as low as it goes (it's only about 15 feet away from where I sit when using the remote), and folded its antenna in, in an attempt to reduce its sensitivity to unwanted interference. That seems to have eliminated the dim flickering of its RF light (at least so far...it's been a couple of hours) and the Replay seems to be responding well...though I've had this experience of jubilation before, only to be followed by disappointment as the intermittent problem returns.

My fear is that this won't work, and that the problem will return, and I'm trying to decide, if it does, whether to continue to bark up this RF interference tree, trying ferrite cores and changing the routing of my wires, and moving the RFX-150 farther from the components, etc.

But it only makes sense to follow that route if it's true that there could be a reason that the interference is affecting only the ReplayTV and not my other components; is it possible, for example, that the ReplayTV's receptor or circuitry is more sensitive to imperfect, interfered-with signals than the receptors of other components? I can't help but think that, absent something like that, it's totally non-logical for communications with the Replay, but not my other components, to be affected by RF interference, and I am reluctant to embark on a course of RF interference elimination (which seems very trial-and-error-based) if simple logic says that because all my other components work just fine, that can't be the problem. I'd appreciate any thoughts you guys might have on this.

It's rare, but if you have performed many hours doing lots of troubleshooting (Emitter placement, etc.) and are still having issues, it is often time to replace the unit. I rarely have issues unless the device is defective. Here's to hoping the quality control and reliability of the 260 and 350 are higher than their lower priced ancestors.

AHA. Actually, I'm convinced that I just nailed it. Nothing like a holiday at home to give you time to really mess with things. There's a wire that runs from the RFX-150 to one of the MRF-250's. It supplies power to the RFX-150, and carries the data signal from the RFX-150 to the MRF-250's. The RF light was glowing on the RFX-150, indicating "interference," and I put my fist tightly around this wire; the RF light got a lot less bright. Clearly, the interference was getting to the RFX-150 through this wire, not through the air, and my fist was acting as a choke. I tried turning components off one at a time, as suggested in this thread. Turned my receiver/power-amp off, and the RF light on the RFX-150 went totally dark. Turned it back on, interference back. Off again, interference gone. Repeatable experiment! Clearly, when the receiver is on, interference is inducting its way into that wire. Why? Because the damn installer had bound that wire into a tight bundle with a million other wires, most of them coming from the receiver. Goddammit. I undid all his plastic straps and freed the RFX-150's wire from the bundle, and gave it a nice route to the RFX-150 all by itself, and suddenly the Replay is more responsive than it's ever been. I guess it's just more sensitive to "imperfect" signals than some of the other equipment.

The lesson for me is to make sure I've employed a real pro next time...there's more to this than just hooking the right cables up to the right jacks.

And for you guys, if you have any doubts that induction is real, and can make or break a setup (and not just cause a little "hum," this, as far as I'm concerned, is proof.

(Of course, if it turns out my diagnosis is wrong, and the intermittent problem comes back, I'll post again to let you know...but I think I've got it this time.)

First, congratulations on solving your problem. I especially appreciate your debug methodology - nice work.

It would have been an interesting experiment to try a ferrite core at the input to the RF-250, while leaving the source of the noise (the cable bundle) intact.... just to see the impact of the ferrite core.

On a separate but related note.... Since your installer may have been relatively inexperienced, you should probably recheck your installation for other inappropriate cable bundling. Such as signal/speaker/power cables bundled together. It is best to keep these bundled separately from each other. I bundle power cables together, line/signal cables together, and I leave speaker cables and remote controller cables separated from all others. For remote control equipment, I run separate routes that are not parallel to any other cables (well, best effort anyway).

HTBM,

That's a good thought, the cable unbundling. Far as I can tell, as it is now, cables are bundled together without regard to their purpose in life, if they happen to be headed in the same direction. Grrrr.... It'll have to wait til the next holiday; Thanksgiving, maybe.

I just got back from a project in Manhattan.
Condo on the 43rd floor.
MSC 400 with an RFX.
There is a ton of interference bombing in at this height and location. The RFX light was lit no matter what we did. Even with the emitters disconnected. After reading this thread, I went down to one of the 53 Radio Shacks in Manhattan! Found a couple of snap on ferrite cores. I tried the cores with the emitters and other wires without success. Finally Nick the other tech on the job slid the ferrite core directly on the antenna of the RFX. Dead quiet!! Remote now works consistently after a couple of days of testing.
I suspect that we are just attenuating the signal,but success is success.
I tried it on mine at home and things seem a little snappier as well.
It is interesting to note that a Niles Intellicontrol in the next room(in the same condo) running at the 418mhz does not have any problems at all? I recall Niles upgrading their RF stage a few years ago. Adding about $100 to the cost. I would speculate we will see an upgrade for the RFX from URC in the near future. It needs some help I would say.