JP1 Remotes

[jwkxneud]

HTPro and 9910 owners: Do any of you have problems with the RF-IR repeater blinding your devices with IR noise?

I just figured out that my V880 is unresponsive to its remote when the repeater is plugged in. It behaves as though the unit is spewing IR noise and obscuring the signal. I don't have to be using the HTPro. As long as it's plugged in, it masks signals from the remote.

My other devices work fine with the repeater. I wonder if it's picking up RF noise from something and broadcasting it on IR, or if it's just emitting some background level of IR all the time regardless of any RF noise.

[mr_d_p_gumby]

[jon_armstrong]

There is a thread here that discusses the same problem. Near the bottom there are two posts from me and the second of those has information and links for a very good alternative, if you can't get rid of the RF interference.
_________________
-Jon

[jwkxneud]

Thanks very much! That's a great help.

[ledan]

I have seen the hardware modification on remotecentral and would like to try it but I'm not sure if it's the same modification for 9910 because the thread is for remote 15-2117. I have opened my 9910 RF module and seen 224 writen on R24 resistor. Should it be 330 ? Could you give me more information please ?

[jwkxneud]

Btw, if you don't want to modify your hardware, it's also possible to put the repeater in a faraday cage. I eventually figured out that my dvd player was spewing the RF noise. Amusingly, it's also the only device affected by the resulting IR noise.

Anyway, I put the repeater behind some grounded chicken wire, and all is well. The leds can shine through it with no problem. The remote hits it from the opposite side (away from the chicken wire).

I had to experiment a bit with shaping the wire. The eventual shape basically enclosed the repeater as much as possible without shielding the viewing area (where the remote is).

[SilentBob]

I did this mod as well, although I used a variable resistor so I could tune it to the optimal filtering.

I have a question about your faraday cage. I experimented with something similar using aluminum foil (no, not a hat) but it did not help very much. I came to the conclusion that any interference would be picked up by the antenna, and you can't very feasibly block the antenna, at least now without breaking the entire purpose of the device.

Did the faraday cage really seem to help? If so, I'd be curious to understand why the antenna doesn't still pick up the interference. It might be interesting to try building the "cage" inside of the case.

[jwkxneud]

I don't quite understand the question, or how you would build a cage inside the case. Obviously it's the antenna on the HTPro repeater that has to be shielded. It doesn't pick up interference because of the shield. That's the point.

The shield has to be oriented such that it blocks the source of the RF noise, but not the hand-held remote. If the noise and the remote are in the same direction from the repeater, this solution won't work.

If you were talking about putting a shield around the source of the noise, that could work, too. However in my case the noise was from a dvd player, and you can't really shield the front of a dvd player and still be able to use it. Putting shielding in the case probably wouldn't work, either, because there are too many openings (for the loader and for the display). By experimentation it appeared to be the loader that was generating most of the noise.

The cage makes a dramatic difference. Without it the dvd player doesn't work at all, even if you're holding the original remote six inches in front of it: the IR port is completely overwhelmed by noise.

[SilentBob]

I understand. I was thinking that you were shielding the internals of the repeater from the noise, not the antenna itself. You have basically made a directional antenna for the repeater. Unfortunately, since I use the remote all over the house, there isn't any place that I can effectively shield the antenna.