ghosted signal on av channel

moosegoose

hi i have a ghosted signal on my tv its only present on the av channel. it looks like a zip going across the screen with some vertical line going from left to right. it looks some thing like this








|||||||||||||||||||||||||||||||||||||||||||||||||| ||||

i also noticed identical interferance on a freinds tv all so on the av channel
any one know what the cause is many thanks.

moosegoose

hi i decided to goggle the subject and its quite a common fault with a simple answer. just cut pin 19 on either end of the scart lead problem solved.

PaulR

It's caused by using a very cheap scart lead.

Better quality ones have the individual wires inside the bundle screened with their own earth shield. Cheap ones just have a bunch of wires held close to each other.

A scart lead is bidirectional, which means that signals go both ways. What many people don't realise is that a TV also puts a signal OUT of the scart socket of whatever channel it's tuned to. The interference you saw is the TV channel video signal leaking into the lead that carries the video from your receiver into the TV.

TBH the solution you've come across will work and stop the TV video signal interfering but you'lll find a general degradation in quality as all the other signals interfere a little bit with each other.

A much better answer is a quality, shielded cable. It doesn't have to be a wildly expensive oxygen-free one either, just shielded.

PaulR As I get older I find myself thinking about the hereafter - I go into a room and then wonder what I'm here after.

Robbo

I recently had the same problem when using 5m long scart leads (cheap ones), I didn't realize there was an easy solution. My solution was to make up some component video cables instead (using sat cable), perfect picture now. I suppose the same could be done using scart to phono adpaters.

moosegoose

thanks paul for the explanation i will replace the lead. but my friend has a 5 meter scart running in the wall to a wall mounted tv .which is connected to a freeview box so he can not replace the cheapo scart. he do have a hdmi cable also in the wall again not the best quality but if he was to upgrade to a freeview with a hdmi would this be ok as it would be digital connection not analogue one many thanks.

PaulR

Sorry for the delay in replying mongoose.

HDMI is probably the best answer.

This is, as you say, digital, which means that as long as the signal gets through then you will get a picture (and sound) as good as you're going to get. Just at the point where the signal is about to be too weak the picture starts breaking up into blocks before disappearing.

An expensive lead gives no better picture than a cheap one. Like I say, if the signal gets through than that's good enough.

PaulR As I get older I find myself thinking about the hereafter - I go into a room and then wonder what I'm here after.