Interference Problem - Advice please.

Mark Greaves

Established Member

I have a new Sony KV28LS35 TV that suffers from interference on BBC1. I don't have a digi box (yet) so just get the 5 terrestrial channels. BBC1 suffers from a background pattern of diagonal lines - quite fine and close together sloping down from left to right at 45 degrees.

I have tried to eliminate all sources of interference. It still appears when every other electrical item in the house is switched off (and unplugged if possible) so I don't think the source is electrical. My aerial is currently in the loft (with a booster) whilst I get round to putting a better one up outside in preparation for getting a free to air digi box. I experience a little bit of ghosting but the picture is quite decent otherwise. When watching BBC1 through the video (i.e. TV tuned to video and video tuned to BBC1) there is no interference and another TV plugged into this same aerial did not suffer from any interference on BBC1 either. As a further test, I took a small detachable loop aerial from the back of a portable TV and ran the Sony off this instead. The picture was suprisingly good but I got exactly the same interference pattern on BBC1! This, and the lack of BBC1 interference via the video or the other TV, shows that the loft aerial is OK.

I have read that a "Herringbone" interference pattern could come from too strong a signal. If the pattern I describe is "Herringbone" could it be that I happen to have a very strong BBC1 signal and the Sony's tuner is more sensitive than the video's or other TV's? The interference only appears on BBC1 and is present whether the loft aerial booster is on or not.

Does anybody have any tips or advice on what might be the source of interference and how to get rid of it? If it is too strong a BBC1 signal is it possible to some how weaken the input or reduce the sensitivity of the TV's tuner? I thought I would seek advice here and investigate all possible solutions before I call on my John Lewis 5-year guarantee. Thanks in advance for any replies.




Established Member
Have you tried using the manual tuning option to fine tune the channel? This sometimes will get rid of interference.

If this fails and the pattern is herringbone then you might like to try an in-line attenuator. It plugs between the aerial and the TV and reduces the signal strength. They cost £2-£5 and used to be available from Tandy, although since they closed down I guess somewhere like Maplin??

Good luck! :)

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