TV interference (intermittent) - Grounding or Loose Neutral?
Asked Sep 28, 2009, 07:53 PM
I am experiencing intermittent TV interference (a brief moment of pixelation and drop or "pop" in audio), which occurs when lights, the air conditioner, a ceiling fan or bathroom fans turn on or off from ANYWHERE in the house (not just in the TV living room area)
How I have attempted to isolate the cause of the interference:
- Antenna reception/interference? - Nope. I have a digital antenna in my attic, and first thought this was the culprit. However, I then noticed the analog cable from COX has the same interference, even when I unplug the antenna coax. So it isn't caused by the antenna and/or poor reception. By the way, all my channels come it at full signal strength.
- Antenna in the attic instead of on the roof? - Nope. I have tested the antenna outside on the roof and the problem is the same.
- Dirty power or Radio frequency interference? - Nope. I have tried ferrite beads/coils, and EMI chokes on my coax cables. I have also tried surge protectors with EMI noise reduction (70dB), and CleanPower technology. The result: no improvement.
- Circuit overload? - Nope. Oddly enough I had all my A/V equipment running, and I plugged in our 12amp vacuum cleaner into the same 15amp outlet, and the reception didn't even give a hint of flickering or interference whatsoever!
- Need a dedicated circuit (home run)? - Nope. I ran an extension cord to my disposal outlet -- a 20amp dedicated circuit. The result: no improvement.
- Need an Uninterrupted Power Supply (UPS) or Automatic Voltage Regulator (AVR)? - Nope. I wondering if the brief interference was possibly caused by a dip or spike in voltage to the house, when a device is powered on or off. I bought a UPS with AVR. The result: no improvement.
What I suspect may be the cause of the problem:
- Poor grounding? - While I have grounded the antenna with a grounding block and groundwire, I saw no improvement. However, I suspect that maybe the entire house isn't grounded properly. Poor grounding could explain why the whole house is affected, not just a specific circuit. In addition, my recent studies have talked about the importance to have electronic devices properly grounded to reduce transmitted interference.
- A loose neutral? - This is out of my area of expertise, but an electrician mentioned this could be the problem. Does this sound correct?? Can these interference symptoms I have described be caused by a faulty/loose neutral? Is that something I can check for and/or tighten up myself?
Any ideas? PLEASE HELP!