hearing radio through TV - Page 2 - Canadian TV, Computing and Home Theatre Forums

mr weather · 2009-09-17, 08:31 AM

I'm sure PG44 wouldn't be the first to have CJOY interference issues.

Just talk to the hundreds of people who live around the transmit towers of CFRB in the Clarkson area of Mississauga. The RFI around there is insidious: telephones, tv's, some appliances!

ScaryBob · 2009-09-17, 08:39 AM

Since the station is still there with the cables disconnected, I doubt it is the fault of the cables themselves. Ve3sy is quite likely correct about the power line causing the problem. Poor design in the TV is quite likely another cause. I have doubts as to how well ferrite cores will works as well. They are effective in some situations but with signals this strong may have little effect. My suggestion is to get a good quality line filter and use it for all the A/V equipment connected to the TV. You may also need to install a line isolator on the cable TV coax.

I use something similar to the Trippe-Lite HT10DBS. When used on the TV and all associated equipment, it will help eliminate ground loop problems and provide a high degree of RF filtering on the power line. The price may seem a little high but it is lower than other, similar solutions. A simple power bar or surge protector will not solve this issue.

Something like the Jensen VRD-1FF will eliminate ground loops and help prevent AM band RF from entering the TV from the cable TV coax.

PG44 · 2009-09-17, 10:21 AM

This is a fascinating issue, and one I will have to research further while trying to resolve. I did check for the interference after I turned the TV off and it was quiet. The coax does not appear to be the culprit since the interference is more audible with connecting other external devices not related to the coax. If it is the power supply I will investigate ways of reducing it. Luckily this is the family room TV which is almost ALWAYS on Treehouse

. I don't have the issue with the Samsung LCD in the bedroom which is directly above, so perhaps the TV is also playing a role.

Thanks again for all the useful input.

JamesK · 2009-09-17, 10:28 AM

That area has both CFRB & CHUM AM, which is south of CFRB on Lakeshore Rd. When I was a kid, living in the east end of Oakville, CFRB often caused interference to other stations. In those days, most kids wouldn't be caught dead listening to CFRB. ;-)

MelanieK · 2009-09-24, 09:17 PM

I am having the same problem with my Sony 32" TV. The TV is 10 years old and it hasn't always done it so I am wondering if the TV is potentially on its last legs. I am located in Halifax, NS and there are no radio towers close by.

CamDAB · 2009-09-24, 09:54 PM

PG44...

Try this simple test to see if it's coming in via the AC line (a common point of entry for RF):

With the TV on a channel with soft audio, and the AM station audible, wrap a goodly portion of the AC line cord from the TV around your arm. Body capacitance plus the coiling action will act as a crude filter and hopefully the radio station's audio will reduce. If not, it sounds a lot like, as others have suggested, direct ingress. And that's the hardest to deal with. If the AC line or other connections were the source, then that's often more easily dealt with.

If the AC line is the culprit, a good EMI/RFI AC filter will help. The main task is finding the point(s) of entry.

Cameron
VE3GVG

PG44 · 2009-09-24, 11:08 PM

Hmm. I'll give that a try and post an update.

wolfsdad · 2012-04-11, 07:49 PM

3 different times in the past two weeks my wife and I have been awakened by what sounds like a piece of electronic gear lighting off, then some sort of broadcast is coming from the tv in our room, but it's not even on. I unplugged it just to make sure the Poltergeist thing wasn't happening, and that killed the sound. Can't quite make out the broadcast, once it sounded like Japanese voices, once it sounded like a weatherband announcer. Any ideas?

57 · 2012-04-11, 11:46 PM

If you're connected via HDMI, make sure that the TV's (and AVR's) HDMI Link feature is turned off - see item 4 of the following HDMI FAQ. If that's not it, then please provide us with exact information regarding the makes/models of your TV, items connected to the TV and type of connection used. It's possible there may be some IR interference from a neighbour or other device which is causing something to come on, or perhaps some sort of power surge or static electricity. Also make sure nothing's on a timer.

http://www.digitalhome.ca/forum/showthread.php?t=71112

I just noticed this:

Quote:

...but it's not even on...

Are you sure? There's usually a status light on the TV to indicate if it's on or off. Just because there's nothing on screen doesn't mean it's off. I assume you heard the sound from the TV's speakers since unplugging it stopped the sound.

Here's a post useful for those new to the forum - FAQs, Search Tips, Optimization, etc.

http://www.digitalhome.ca/forum/showthread.php?t=57741

JamesK · 2012-04-12, 07:20 AM

What you have sounds like audio rectification. This results when the affected equipment detects radio transmission. In extreme cases, the equipment doesn't even have to be on.

2009-09-17, 08:39 AM	#17
ScaryBob Veteran Join Date: Feb 2009 Location: The Dandelion City Posts: 7,133	Since the station is still there with the cables disconnected, I doubt it is the fault of the cables themselves. Ve3sy is quite likely correct about the power line causing the problem. Poor design in the TV is quite likely another cause. I have doubts as to how well ferrite cores will works as well. They are effective in some situations but with signals this strong may have little effect. My suggestion is to get a good quality line filter and use it for all the A/V equipment connected to the TV. You may also need to install a line isolator on the cable TV coax. I use something similar to the Trippe-Lite HT10DBS. When used on the TV and all associated equipment, it will help eliminate ground loop problems and provide a high degree of RF filtering on the power line. The price may seem a little high but it is lower than other, similar solutions. A simple power bar or surge protector will not solve this issue. Something like the Jensen VRD-1FF will eliminate ground loops and help prevent AM band RF from entering the TV from the cable TV coax. __________________ At 20 I had a good mind. At 40 I had money. At 60 I've lost my mind and my money. Oh, to be 20 again. --Scary

2009-09-17, 10:21 AM	#18
PG44 Join Date: Jan 2009 Location: Guelph, Ontario Posts: 246	This is a fascinating issue, and one I will have to research further while trying to resolve. I did check for the interference after I turned the TV off and it was quiet. The coax does not appear to be the culprit since the interference is more audible with connecting other external devices not related to the coax. If it is the power supply I will investigate ways of reducing it. Luckily this is the family room TV which is almost ALWAYS on Treehouse. I don't have the issue with the Samsung LCD in the bedroom which is directly above, so perhaps the TV is also playing a role. Thanks again for all the useful input.

2009-09-24, 09:54 PM	#21
CamDAB Join Date: Mar 2006 Location: Far East End of Hamilton, ON (Lake & Barton, 10th floor facing East) Posts: 1,089	PG44... Try this simple test to see if it's coming in via the AC line (a common point of entry for RF): With the TV on a channel with soft audio, and the AM station audible, wrap a goodly portion of the AC line cord from the TV around your arm. Body capacitance plus the coiling action will act as a crude filter and hopefully the radio station's audio will reduce. If not, it sounds a lot like, as others have suggested, direct ingress. And that's the hardest to deal with. If the AC line or other connections were the source, then that's often more easily dealt with. If the AC line is the culprit, a good EMI/RFI AC filter will help. The main task is finding the point(s) of entry. Cameron VE3GVG __________________ DAB listener December 2003-November 2011 (DAB Off-Air) HD radio Listener since June 2010

2012-04-11, 07:49 PM	#23
wolfsdad Rookie Join Date: Apr 2012 Posts: 1	radio coming through tv, but tv is turned off! 3 different times in the past two weeks my wife and I have been awakened by what sounds like a piece of electronic gear lighting off, then some sort of broadcast is coming from the tv in our room, but it's not even on. I unplugged it just to make sure the Poltergeist thing wasn't happening, and that killed the sound. Can't quite make out the broadcast, once it sounded like Japanese voices, once it sounded like a weatherband announcer. Any ideas?

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2009-09-17, 08:31 AM	#16
mr weather Veteran Join Date: Nov 2002 Location: Mississauga, Ontario Posts: 1,950	I'm sure PG44 wouldn't be the first to have CJOY interference issues. Just talk to the hundreds of people who live around the transmit towers of CFRB in the Clarkson area of Mississauga. The RFI around there is insidious: telephones, tv's, some appliances!

2009-09-17, 10:28 AM	#19
JamesK Veteran Join Date: May 2009 Location: Mississauga Posts: 5,036	That area has both CFRB & CHUM AM, which is south of CFRB on Lakeshore Rd. When I was a kid, living in the east end of Oakville, CFRB often caused interference to other stations. In those days, most kids wouldn't be caught dead listening to CFRB. ;-)

2009-09-24, 09:17 PM	#20
MelanieK Rookie Join Date: Sep 2009 Posts: 1	I am having the same problem with my Sony 32" TV. The TV is 10 years old and it hasn't always done it so I am wondering if the TV is potentially on its last legs. I am located in Halifax, NS and there are no radio towers close by.

2009-09-24, 11:08 PM	#22
PG44 Join Date: Jan 2009 Location: Guelph, Ontario Posts: 246	Hmm. I'll give that a try and post an update.

2012-04-12, 07:20 AM	#25
JamesK Veteran Join Date: May 2009 Location: Mississauga Posts: 5,036	What you have sounds like audio rectification. This results when the affected equipment detects radio transmission. In extreme cases, the equipment doesn't even have to be on.