We have a job that the homeowner has a 20amp dedicated circuit for both the master bedroom, and the family room. He has quite a bit of equipment at both locations. He supplied all of the equipment outside of the remotes, and the equipment includes a Moster HTS3600 in the closet, a HTS2000 for the master Plasma, video switcher (Pioneer Plasma with off board video switcher), and sub. In the family room he has a Panamax M5100. With pretty much everything running through it as the surge/conditioner. I could list out all of the equipment, but I'm not sure the keyboard has enough letters to do so..sigh....

Now it gets weird. His ceiling fan switchs in the family room, and master bedroom are an RF 3 button control. It controls obviously the speed of the fan. When you turn on the fan in the master or the family room the sound from the sat box cuts out for about 1 second. If you watch the display on the receivers you notice that the normal "Dolby Digital" goes away for a split second and shows "PLXII" Prologic. Then it goes back to DD. It's almost as if the Sat receiver stops sending audio for a second. This was noticed before the dedicated circuit was installed. I immediatley pointed to the fan controllers as the problem, but we noticed that the standard light switch for the light on the fan would do the same thing about every 10th time you flipped it on or off. After the didicated circuit was installed it continued. His older Z1 died, and we replaced it with a new Z11. The family room no longer does this, but the master continues to switch the audio as before. He has a nice Yamaha in the master (don't know the model, but he got it on sale for $2800), so I'm not sure why the receiver change in the family room stopped the issue.

I'm baffled. The elcetrician is befuddled, the builder just shakes his head, and the homeowner is beside himself.....I don't know where to look fellas.

I would run a long extension cord from a different circuit in the house to the Master Bedroom. Then plug the both the sat receiver and AV receiver into the extension cord, both together and individually. This can help you determine if indeed perhaps some inductive pulse from the Master Bedroom AC line when the fan is controlled is causing the digital audio to drop and if so, which component is being affected.

Not sure what kind of fix would work best if the problem is isolated to the fan switch...

Maybe double check the fans wiring to make sure it is correct?

Maybe a higher quality fan or fan controller?

I just don't understand how this could happen with the AV equipment on a dedicated circuit, and using a stage 3 surge protector.

Scotty, you are right. It can not happen over a dedicated circuit and I would focus elsewhere. I remember a thread here about a similar problem. You may want to start by searching for it unless someone remembers the outcome. Is it possible the ceiling fan has 2 way communications or the physical switch also puts out an RF burst? A call to the manufacturer might also be a place to start.

Are they Dish Network sat receivers?
If so, they can be controlled using their RF remotes, so I'd guess that the fan RF controllers are send a signal that is also used by and conflicts with the sat receivers.

Same with Directv receivers, but that would not explain the light switch causing it.

Just blame sparky and be done with it.

As usual, I missed a small but important detail.

I was actually having the same problem at my house. The situation was a little different, dedicated outlet on my gear but anytime the AC kicked on or we turned on/off the lights in the room the audio from sat wood cut out for a split second. The dedicated outlet isnt for the room it is just for the rack. I thought maybe an optical cable problem, the receiver I was using only did HDMI switching so it was a great excuse to get a new receiver also. Switched to a Z11 and hooked up optical again and still had the same problem. Switched to HDMI and the problem was still there. It only went away when I added a M1500UPS and a M5100PM from panamax. I was just using an M4300. Dont really know why but thats what fixed it.

Your right Phil, and I'm sorry I did not do a better job of pointing that out AJF. The light switch did it.

They are Direct TV boxes. A H21 in the family Room, and a HR21 in the bedroom. We are using RF remotes as well, but we are using the narrow band stuff from URC. I did the sniff test on 0, and saw nothing.

Phil. I would love to blame the Sparky if I thought I would have a leg to stand on, but neither of us can figure out what the issue is. We are using HDMI to the receiver at both locations but I doubt adding an optical cable would accomplish anything.

Most baffling is why it stopped in the family room when I changed the receiver.

ScOtty,
It would be about five years ago that I was working on two different jobs about the same time, and ran into a similar problem on each one. One job was a very simple set up, a CRT TV and a Digital STB, the other, a Projector, AV Receiver, Digital STB, etc. In both cases, when a light switch was turned off (various switches around the house, but always the same ones), the picture would freeze momentarily. In the second house, closing the fridge door would cause the picture to freeze!

I will add, both of the houses would have been at least 15 years old, after some discussions with an acquaintance I connected a capacitor rated at 275 volts, I can't remember how many micro farads, and it was obviously non polarising (someone will know the right term), and connected it across the offending light switch, no more problems. It allows the voltage to bleed off without causing a glitch. Never got around to doing the switch for the fridge light, I think the client used it as a excuse to buy a new fridge.

During a recent conversation, it was suggested that the offending light switches would more than likely have been in high usage areas and needed replacing. Doesn't explain why changing the Family room receiver stopped the problem though!

I’m confused. How would this happen if the switches are on a completely different circuit? It would make me think that the problem lies in the panel. Possibly something to do with the neutral. ?????????? I will follow this thread to the end as my curiosity is at a whole new level. All of the facts in here do not compute with me so Scotty; I totally understand your frustration. I hope Ernie or one of the other scientific geniuses pops in here with an answer I can understand. Until then, I share in your frustration.

Bump

Maybe you should ask the electrician to make sure the two circutrs are not on the same phase. When we are doing new construction we always ask the sparky to put all our AV circuts on the same phase to help reduce ground loops and other problems.

Good luck

Make sure when sparky say's dedicated that he didn't just mean a hot wire and he is sharing the neutral wire with the fan and rack. The receiver that you changed out, did it change from or to a 3 prong form 2?

I think it would be a gas if you were to remove the Monster power thingie and find that the problem went away. You really should try it. And I'm not kidding.

Maybe you need a Tice Clock. Write to Mr. Stanley about that.

The capacitor across the light switch makes sense. Probably 0.25 microfarad or more would be good, rated at 275 VAC (NOT 275 volts without saying AC; if not saying AC, go for 400 volts). I think the term is non-polarized or polarised, depending on whether the pond is on the right or the left.

Lousy, that is, worn, switch contacts make sparks. Sparks send out random strong RF, and that's how I can see the switch causing some kind of problem. Can't understand this one at all, though.

Anybody out there know what the IF frequencies are inside of a satellite receiver? Are there any? PLLs run at what frequencies?

I was baffled from the start that two rooms are on one dedicated circuit and it's called a dedicated circuit. Or maybe you didn't mean that. And that turning the fan on or whatever caused audio to blank out on both receivers. I'd like that clarified.