60 hz hum

Execut1ve · #1 06-25-2010, 02:57 PM

I have a hum in my entertainment system which I have isolated to my digital cable, which runs into my receiver as a coax. I'm almost certain it's a 60 Hz hum. Any quick or easy or cheap fixes?

Thanks!

bongomania · #2 06-25-2010, 03:13 PM

Try a new cable.

TheSuzie · #3 06-25-2010, 03:43 PM

MakiSupaStar · #4 06-25-2010, 03:56 PM

Turn the volume down on the world cup match.

MatticusMania · #5 06-25-2010, 04:50 PM

I was just about to say, remove the vuvuzela from your signal chain.

Bob Lee (QSC) · #6 06-25-2010, 05:29 PM

Exactly: Do a vuvuzela delete.

Actually hum arising from a cable TV hookup is fairly common; I think cable systems have pretty noisy ground potentials, at least in the audio frequencies.

Look here for a product called the VRD-1FF: http://www.jensentransformers.com/iso_vid.html

It should solve the problem.

KeithBMI · #7 06-25-2010, 05:37 PM

It could be caused by a redundant ground. Make sure that none of your cables are touching the floor.

MJ5150 · #8 06-25-2010, 06:31 PM

Crank up the bass and charge $15 for two minute rides on it.

-Mike

Execut1ve · #9 06-25-2010, 08:20 PM

here's a possible solution:

The house was built around the turn of the century (not the most recent century... I mean early 1900's) so the electrical wiring was all 2-prong stuff, probably the porcelain knob style. An electrician replaced some of the 2-prong sockets with GFI's, but I don't think he actually physically grounded the outlets... I'll have to check to see if they are.

crentest · #10 06-25-2010, 08:47 PM

Quote:

Originally Posted by Execut1ve

here's a possible solution:

The house was built around the turn of the century (not the most recent century... I mean early 1900's) so the electrical wiring was all 2-prong stuff, probably the porcelain knob style. An electrician replaced some of the 2-prong sockets with GFI's, but I don't think he actually physically grounded the outlets... I'll have to check to see if they are.

gfci's would be in place of earth ground.
knob and tube wiring is usually noisy, the 60 cycle hum is not phase canceled.

Execut1ve · #11 06-26-2010, 09:40 PM

Quote:

Originally Posted by MakiSupaStar

Turn the volume down on the world cup match.

Quote:

Originally Posted by MatticusMania

I was just about to say, remove the vuvuzela from your signal chain.

Just an informative note, the vuvuzela plays a note around Bb3 (according to http://en.wikipedia.org/wiki/Vuvuzela ), the frequency of which is 233.08 Hz (according to http://en.wikipedia.org/wiki/Scientific_pitch_notation ). So my 60Hz hum is probably not caused by any vuvuzelas... unless we're talking about the rarely seen bass vuvuzela, as the frequency of the Bb two octaves below Bb3 is close to 60Hz

baalroo · #12 06-26-2010, 10:25 PM

Vuvusubcontrabassela?

beelzelboss · #13 06-27-2010, 11:44 AM

Quote:

Originally Posted by baalroo

Vuvusubcontrabassela?

Thats amazing. Love it.

baalroo · #14 06-27-2010, 04:38 PM

Quote:

Originally Posted by beelzelboss

Thats amazing. Love it.

WorkinOnIt · #15 06-27-2010, 06:27 PM

Quote:

Originally Posted by Execut1ve

I have a hum in my entertainment system which I have isolated to my digital cable, which runs into my receiver as a coax. I'm almost certain it's a 60 Hz hum. Any quick or easy or cheap fixes?

Thanks!

Is your power coming from a single plug for all devices?

I used to have a NASTY 60hz hum in my music room. After lots of troubleshooting and trying hum eliminator devices and stuff, nothing really did the job to my satisfaction. My bass teacher suggested using a single outlet, so I reworked the room and rearranged things to use a single outlet and that did the trick. Good luck.

Execut1ve · #16 07-02-2010, 10:32 AM

yeah, they are all plugged into the same outlet. Time Warner is sending someone sunday to look at their end of it, hopefully that solves the problem. If not, perhaps one of those power strips that you can run coax through would work?

Bob Lee (QSC) · #17 07-02-2010, 10:33 AM

Electrical codes in recent years have required that cable TV cabling be brought into a home near the main service box and bonded to it.

If your installation predates that, it probably isn't bonded. Look here for a product called the VRD-1FF: http://www.jensentransformers.com/iso_vid.html

Execut1ve · #18 07-17-2010, 07:32 AM

incidentally, the issue was resolved by getting a fancy power strip that included an input/output for coax. I figured I could spend $40 on a gamble, and if it fails I still get a good power strip, rather than running out to buy a $50+ filter that might not work and has no other function