AND a technical response from URC might help. Hell, even if they acknowledged this thread

I will be trying the ferrite cores on an MX350 with an MRF250 base station. When I had just 1 emitter connected to the system it was picking up very little RF interference but once the rest of the components were connected with the emitters connected to the base station the system was rendered pretty much useless. The client now has to leave his cabinet doors open until the ferrite cores show up and I can hope to fix his issue. If not then we will have to go with something different in his home.

I don't see how anyone could reasonably spec a MRF-250 into a client's system. At least go for the MRF-300 and MRF-350. Of course I'd never think of a customer with an MX-350 either! The consumer level remote?

Will something like this work?

[Link: partsexpress.com]

I would think so, almost any size should provide significant improvements. Still, these are still quite large, so having multiple of them might be a little bulky. You should be able to bundle all the cables into a single ferrite and get similar results. Try it.

I would guess most of you guys here are installers. When I used to install Plasmas, only Panasonic UK, they were always supplied with more ferrite rings than needed. They make great RFI suppressors. Most of you will know that mearly clamping the ferrite around the cable is not a enough, make sure you wrap a good few turns around the ferrite before closing it. Use tape or tie straps to make sure they cable doesn't come loose. Every audio, video and mains lead in my system rack has a ferrite core on it. That's mainly because my dad is an amateur radio operator and his three aerials are in the back garden, but one is over my room.

Thank you for the info , this worked perfectly and it was on a mrf-300.I did want you said and it went from a 20% working ,80% not to about 100% so a big difference.

thanks

Well I'm going to jump on board and try this out. I've got a smallish install with a disfunctional MRF300. I actually had to go to radio shack to get the install taken care of right away. Jesus what a rip-off, $6 each for cores. If they work, its well worth it though.
I did find and order a bag of 100 off ebay for $29 including shipping. Figure it cant hurt to have them on hand. Dont know if ebay links are allowed, but a search for ferrite core popped up plenty.
Wish me luck!

-Zeke

I tried the ferrite cores from Parts Express that Mitch found and they do seem to work well. The opening isn't very big though. I was able to wrap the power cord through it 3 times, and the emitters twice, albeit I'm using Xantech double emitters on my MRF-250 and the wires may be thicker then the standard ones.

(If anyone is curious how I'm doing that, search for 3.5mm to 2.5mm adapters)

I had removed the antenna from my unit because it had been picking up so much interference, but since adding the RFI filters I've slapped it back on.

Ferrite cores, or even removing the IR Blasters entirely, has no effect on my MRF100A V1.0. With no wires attached except power, it acts very much like an electronics-detector; status light illuminating near any A/V device. Removing antenna (or holding it) helps a bit, but not enough. Only distance from all electronics seems to help. Having the blaster wires with lots of other wires doesn't appear to have much impact. (And I have a doozy of a bundle going through a conduit for about 8 metres, connecting the A/V electronics to the monitor, speakers, powered subs, ButtKickers, CAT5, etc.)

I tried ferrites on everything, soldered in the bulk-load capacitors, and put my RFX antenna up as high as I could near the ceiling over the equipment to get it farther away. This weekend I was ready to tear it all out and start over with another brand, I was so frustrated. Intermittent operation, and the MSC400 kept routing all the commands to all the blasters instead of individual ones.

So, today I got a bunch of cat-5 I had leftover from something else, ran it down into the basement, and back up into the room fifteen feet away from the equipment, behind the television. Works like a charm. Makes me wish I had gotten frustrated enough to do all this work earlier.

Well, not really, but you get the idea. ;-)

Hello everyone,
I've read so many post with RFI and I'm having big time problems because of this.

I've installed 3 MX-3000 with MRF-350 in hotel rooms to simplify the use of the electronic devices.

Because of RFI, the MRF is missing part of commands, so the system is always screwed up and my variables are not working well because of this.

I've tried a few things... and they never completely worked until...

I had not problems with the cable between the RFX-250 and the MRF-350, so the antenna was my problem.

I then off the antenna from the RFX-250 and replaced it by one 22 gage wire. It worked well. I then thought that maybe i was just lucky and i solved my problem so i decided to put back the antenna. RFI came back. I then left the antenna on the RFX-250 and took the 1 feet long 22 gage wire and twisted a small part of it around the metal base of the antenna and RFI was gone again.

The satus light did not flash for a minute.

Is this a solution?

Tell me what you think.

If i touch the metal base, RFI dissipears too.

I really need your thought on this.

Thanks

so what does the cat 5 do- i am a little ignorant. since it is noise on the antenna, how does the cat5 help?

There are probably multiple sources for interference, but they are getting into the MRF unit by only a few pathways: 1) the IR emitter cables, 2) the antenna picking up adjacent frequencies or harmonics from strong signals, or 3) the MRF unit itself picking up RF interference.

I would hope the design of the MRF would include sufficient EMI/RFI shielding to make #3 a non-factor.

In my case, it was all about the IR emitter cables. Ferrites worked just fine. But replacing the IR emitter cabling with twisted pair wire (as in cat5 cable) would also tend to reduce interference. There is also shielding in some cat5 cabling that could be grounded to further improve the noise immunity of the cable itself.

I think if you can unplug the IR emitter cables and the lights go off, then you're picking up the majority of RFI from the IR cables. But if the lights stay on, you are getting RFI induced into either the MRF unit itself, or the antenna is picking it up.

By touching the antenna, or twisting the wire around it, you are reducing the gain of (or attenuating) the antenna at the desired frequency. This also reduces the level of both the interference and the "good" signals from the remote. While this might not improve the overall S/N ratio, it does attenuate the absolute level of the "bad" interference.

People tend to think there is ONE problem, so there is ONE best fix. But sometimes there are multiple problems at the same time and the additive effects of them combined put you into this pickle. You might be able to reduce one of them sufficiently where it becomes tolerable.

Somewhere in the maze of home theater equipment, there may be some device that emits crazy amounts of RFI. Try powering them off one by one to see if the lights go out on the MRF - maybe there is one bad boy that is spewing out RF like crazy.