Jump to content


Welcome to DBSTalk


Sign In 

Create Account
Welcome to DBSTalk. Our community covers all aspects of video delivery solutions including: Direct Broadcast Satellite (DBS), Cable Television, and Internet Protocol Television (IPTV). We also have forums to discuss popular television programs, home theater equipment, and internet streaming service providers. Members of our community include experts who can help you solve technical problems, industry professionals, company representatives, and novices who are here to learn.

Like most online communities you must register to view or post in our community. Sign-up is a free and simple process that requires minimal information. Be a part of our community by signing in or creating an account. The Digital Bit Stream starts here!
  • Reply to existing topics or start a discussion of your own
  • Subscribe to topics and forums and get email updates
  • Send private personal messages (PM) to other forum members
  • Customize your profile page and make new friends
 
Guest Message by DevFuse

Photo
- - - - -

Plasma TV & RF Interference


  • Please log in to reply
4 replies to this topic

#1 OFFLINE   jclangston

jclangston

    Cool Member

  • Registered
  • 40 posts
Joined: Oct 19, 2010

Posted 18 December 2013 - 01:33 PM

Does anyone have a fairly high powered power amp near a Plasma TV?  I have a Emotiva 200W x 5 channel power amp, the issue I'm having is that I get feedback into my amp from the Plasma TV.  Even when the volume is at 0 I get a mild hum through my speakers.  If I unplug the Plasma the hum goes away.  Has anyone experienced this?  I'm not sure if its RF waves traveling through the air or if its back feeding through the wiring in my house.  I was thinking about buying a UPS that has a line conditioner built in, but I didn't want to spend the money if it wouldn't help.  



...Ads Help To Support This SIte...

#2 OFFLINE   inkahauts

inkahauts

    Hall Of Fame

  • DBSTalk Club
  • 16,218 posts
Joined: Nov 13, 2006

Posted 18 December 2013 - 01:48 PM

Try a line conditioner. That's likely the culprit. A ups with one built in would be nice but you wouldn't want to buy one for your amp just your tv as one that would not hinder your amp would cost a lot of money.

#3 OFFLINE   kenglish

kenglish

    Icon

  • Registered
  • 972 posts
  • LocationSalt Lake City, Utah, USA
Joined: Oct 02, 2004

Posted 21 December 2013 - 04:25 PM

Do you get the hum when the Plasma TV is plugged in but not turned on?

Or, just when it's actually running?

 

In the first case, that might indicate RFI from the switched-mode power supply....most likely (conducted) via the power wiring or the interconnect cables.

Some sort of line filter might help, but most don't go down to such low frequencies. If you live in a city, there may be a hospital or a company that services hospital and clinic equipment, that might let you try out an isolation transformer on the power cable. That might help.

Otherwise, some ferrites that are designed for ham radio and AM broadcast frequencies, could be used on those cables....the more-common ones from places like Radio Shack are designed for VHF frequencies (25-250 MHz), so they won't do it.

 

In the second case, it's likely being radiated by the little "arc-generators" in the screen (the actual plasma cells). Moving the amp further away from the TV would help there. try a big piece of metal (like a cookie sheet) as a shield, and see if it makes the noise less noticeable 9as a quick check).

 

Here's a ham/audio engineer's guide:

http://audiosystemsg...com/RFI-Ham.pdf



#4 OFFLINE   gov

gov

    Legend

  • DBSTalk Club
  • 1,100 posts
Joined: Jan 10, 2013

Posted 21 December 2013 - 08:59 PM

And back in the old  days, if we had a non-polarized plug in an outlet, we would try it the other way. If more than one piece of equipment, we would try all the permutations.

 

If there was a 3 prong plug we might try a 2 prong (GASP!) adapter.

 

We could attach or remover the ground wire from the turntable too, LOL.

 

And for the really tough cases, one cold always wall paper with aluminum foil.

 

 

:nono2:



#5 OFFLINE   Rich

Rich

    Hall Of Fame

  • DBSTalk Club
  • 21,395 posts
  • LocationPiscataway, NJ
Joined: Feb 22, 2007

Posted 28 December 2013 - 12:17 PM

Does anyone have a fairly high powered power amp near a Plasma TV?  I have a Emotiva 200W x 5 channel power amp, the issue I'm having is that I get feedback into my amp from the Plasma TV.  Even when the volume is at 0 I get a mild hum through my speakers.  If I unplug the Plasma the hum goes away.  Has anyone experienced this?  I'm not sure if its RF waves traveling through the air or if its back feeding through the wiring in my house.  I was thinking about buying a UPS that has a line conditioner built in, but I didn't want to spend the money if it wouldn't help.  

 

What brand plasma?  I have 8 Panny plasmas and have never had that problem.

 

Hummmmmmmmmmmmmmmmmmmmmm.    :rolling:

 

Rich






Protected By... spam firewall...And...