2. tech-talk
  3. 1046223682

Please help I have a strange grounding problem

I recently bought a FIM 880 outlet and installed it myself. I plugged in my amp and cdp but I'm getting a fairly loud "humming" when I play my tuner only. I don't have dedicated outlets( I'm in the process of making this my next project)so I have my tuner plugged into a Monster Cable 2000 outlet which is in another outlet on the same wall.Both outlets are on the same line as when I shut off the breaker there is no power on this wall. The strange thing is when I unplug the cdp, the hum goes away completely.It only comes back when I plug the cdp back into the same outlet as my amp. Another weird thing is when the hum is there and I get closer to my amp, the hum increases in volume as if my body is acting as an antenna. I'm not a technical guy,but it appears to me that there is some kind of a loop and by unplugging the cdp the loop is taken out. I would surely like some advice on this new and strange situation. Thanks for your help and advice.
sherod
gabbro
88 posts
 
What is your antenna situation? If you improve the reception, it may solve your problem. A good attic or roof-mount directional antenna with a rotor is always a good idea.
sherod OP
1,690 posts
 
I am using a high-end dipole called the FM Reflect from C.Crane,Inc. I think I paid around $60.00 for it.It is mounted on the wall behind the system, carefully camaflouged by bookcases so the wife will leave it there. I may go for an outdoor unit, but FM is not my main source of listening. I'm trying to figure out why I get this background hum in stereo and not in mono.
sherod OP
1,690 posts
 
Well, I've isolated the humming problem to the FIM outlet. Apparently I didn't install it right. I am going to get an electrician in next week to put in dedicated outlets. I'm tired of sharing electricity with the rest of my house and neighborhood.I recently read a good review of an AC filter called the ISO 1100va. Can someone share their thoughts on this item ? Where can I buy one ? Thanks again for all your help in troubleshooting.
sherod OP
1,690 posts
 
Well, I thought I isolated the problem when I started searching the threads under "isolation transformer" and I found a post about coaxial cable causing ground loop hums. I didn't even have my cable hooked up to the T.V., so just for kicks I unscrewed the cable from the wall outlet and what do you know,the hum diminished dramatically.The cable outlet is located right next to the FIM outlet. I'm going to try a Radio Shack trick or two to hopefully resolve this issue once and for all. I'm still going for the dedicated lines, though.
stehno
1,453 posts
 
Glad to hear you've determined the ground loop hum issue. With regard to the AC filters, I'd like to suggest you consider the Foundation Research LC-1 and LC-2 in-line power conditiners.

Though not inexpensive, the LC's begin to look inexpensive when you consider they come with their own power cables and then compare their costs to other excellent quality power conditioners along with high-priced power cables.

Not to mention, with the Foundation Research in-line power conditioners, you are able to take full advantage of all your dedicated lines since you would use one LC per component.

-IMO
More to discover