Mains interference on TV picture?

[The_Lhc]

Some time during Christmas I noticed a peculiar effect on my TV (Pioneer KRP-500a). When watching vertically scrolling credits the text would judder up the screen for a few seconds and then flow completely smoothly for a few seconds before juddering again. At the time we had some christmas lights plugged into the other socket of the dual-gang outlet that the TV is plugged into (only the screen the media receiver is plugged in elsewhere), the sort of lights that run different patterns via a control box, I had thought that the juddering coincided with the lights activating and thought nothing more of it.

However this morning I was watching the end of Lost Land of the Jaguar and when the credits came up I noticed the same on/off juddering effect with the scrolling text. Of course, being March we no longer have xmas lights plugged into the socket, in fact there's nothing plugged into that socket now. There's plenty of stuff plugged into other sockets around the room and knowing the house it's probably all the same ring.

Now I can't be bothered to go around unplugging everything to see which one's causing the effect, frankly the way this house is wired, it could be coming from anywhere. The rest of the gear, bar the AV amp, my router and the NAS (I didn't have the NAS at xmas, so it isn't that) is plugged into a Tacima 6-way, all I really want to know is is there something I can plug the TV into to stop this interference? I don't particularly want to spend a fortune and it can't be anything enormous, ideally I'd like to hide it in the cable management area of my Off the Wall TV stand that the screen's attached to, I don't really want it on show.

If anyone is thinking of starting another cable argument, don't bother, I'm ambivalent on the subject of mains cables and I don't think any amount of screening is going to make any difference in this case as I'm pretty certain the problem is coming from the mains, rather than being outside interference.

 

[Anonymous]

the_lhc:

The rest of the gear, bar the AV amp, is plugged into a Tacima....

lhc why,as a matter of interest, don't you have the amp plugged into the Tacima?

 

[The_Lhc]

Wovian:the_lhc:The rest of the gear, bar the AV amp, is plugged into a Tacima....
lhc why,as a matter of interest, don't you have the amp plugged into the Tacima?

Partly because there wasn't enough sockets on the tacima to accomodate it, so I have it plugged into its own wall socket, partly to reduce the total current draw through the single socket the tacima's plugged into and partly because of the stories of people hearing reduced dynamics in their audio when having their amp connected to a tacima.

Mainly because there wasn't enough sockets though...

 

[Anonymous]

The common theme here seems to be with credits rolling up the screen. What makes you think it's anything to do with the mains?

LCD's are far from perfect devices. my older Panasonic does not like black screens with white writing and emits a noticable buzz when confronted with this type of signal and I get slight juddering of the credits.

 

[The_Lhc]

welshboy:The common theme here seems to be with credits rolling up the screen. What makes you think it's anything to do with the mains?

Because of the intermittent nature of it, it's perfect for several seconds, then judders for several seconds. It's unlikely to be anything the TV is doing itself, so it must be external.

LCD's are far from perfect devices.

So? I've got a plasma.

my older Panasonic does not like black screens with white writing and emits a noticable buzz when confronted with this type of signal and I get slight juddering of the credits.

If it happened all the time I probably wouldn't give it much thought, but it doesn't, 50% of the time it's the smoothest scrolling you could ask for.

 

[scene]

How often does the "intermittent" problem happen?

If it's reasonably often, how about temporarily plugging your Kuro into the Tacima to see if it makes the problem go away? If so, then at least you know buying a mains conditioner / smoother will make a difference.

 

[The_Lhc]

scene:How often does the "intermittent" problem happen?

Difficult to say as it's only noticable with vertically scrolling text (at least if it's affecting anything else it's not visible enough to be apparent) and I don't usually watch the end credits so I've usually switched over by that point.

If it's reasonably often, how about temporarily plugging your Kuro into the Tacima to see if it makes the problem go away? If so, then at least you know buying a mains conditioner / smoother will make a difference.

They're plugged into different walls (the TV is in front, the rack with the gear on is at the side of the room, with just the kuro's system cable (10m) running round the wall to the screen, which is partly why I bought it), I could run an extension from the tacima to the screen and try it I guess, good idea.

If that does sort it, is there a single socket tacima or something of that ilk?

 

[Anonymous]

the_lhc:

If that does sort it, is there a single socket tacima or something of that ilk?

lhc, I don't believe Tacima do a single socket but this is what I was advised to go for on a recent thread ("That cable HDMI purchase") when I had the same question as yourself.

Maintrab 6A mains filter, Transient, RFI protection on eBay

 

[scene]

Tacima do a three-way surge protector, but I'm fairly certain it doesn't do filtering and conditioning.

They also do the slightly odd SC5723/BP, which plugs into another socket "upstream" of the device to be protected, or downstream of the one causing the interference. Have a look on their website: click - it's just below the CS929. I've got no experience of this product, so can't comment on it's efficacy.

Most of the one-way/single-gang protection systems are either surge protection devices only or very expensive...

 

[scene]

Wovian:the_lhc:

If that does sort it, is there a single socket tacima or something of that ilk?

lhc, I don't believe Tacima do a single socket but this is what I was advised to go for on a recent thread ("That cable HDMI purchase") when I had the same question as yourself.

Maintrab 6A mains filter, Transient, RFI protection on eBay

Oops - missed this one

. At that price eBay, might be worth a speculative punt - have you got room for the unit? (Hang on - could plug it into a short extension cable to move it somewhere easier to hide)

 

[The_Lhc]

Ah ok thanks to both, I'll investigate those suggestions.

 

[The_Lhc]

scene:Wovian:the_lhc:If that does sort it, is there a single socket tacima or something of that ilk?
lhc, I don't believe Tacima do a single socket but this is what I was advised to go for on a recent thread ("That cable HDMI purchase") when I had the same question as yourself.

Maintrab 6A mains filter, Transient, RFI protection on eBay

Oops - missed this one

. At that price eBay, might be worth a speculative punt - have you got room for the unit? (Hang on - could plug it into a short extension cable to move it somewhere easier to hide)

I could live with something like that, I just don't want an entire 6 way block lying around when I've only got the screen plugged into it!

I'll try the extension cable from the tacima first though I think.

 

[aliEnRIK]

the_lhc:

If anyone is thinking of starting another cable argument, don't bother, I'm ambivalent on the subject of mains cables and I don't think any amount of screening is going to make any difference in this case as I'm pretty certain the problem is coming from the mains, rather than being outside interference.

Odd given that braided cables reduce mains noise