Freeview interference on TV tuner & DVD tuner but ...

Question

I've got a weird problem that's been plagueing me on & off for the past couple of months...
Intermittently but at no specific times, the freeview signal from the TV tuner and the DVD/HDD recorder become pixellated but the Freeview signal from the BT Vision box is fine.
The aerial cable comes into the Vision box first & then passes through the DVD recorder to the TV. At first I was searching for possible causes of interference within the house - a nwly installed shower, central heating thermostat etc but the problem has still occured at times ie late at night when everything else is switched off.
I cant see why any outside interference would affect two tuners but not the one in the Vision box? Could it be related to cables between the Vision box & the DVD recorder or an internal fault within the Vision box? Pinning it down to where the fault lies is the problem; any suggestions folks ??

Answer 1

TVrepairman wrote:
Do note that the Vision+ box has a very good tuner that often works better than other tuners at low levels. 
Interesting that you say that TVrepairman. Over the last few years there have been many posts on this forum where people report the black BT Vision+ box indicating an inadequate signal whereas all other TV's and boxes in the house indicate a good signal. The BT Vision+ box is usually the first in any chain as well so should get the best signal. This is the opposite of the problem reported on this thread but has led people to generally conclude that the BT Vision+ box has very fussy tuners that require a very good signal. People often also state that the dual tuners mean it requires a better signal, but I would expect it to be boosting the signal internally for the second tuner so don't know if that is really relevant.
Even more interesting is the fact that many other posts reported that using the Classic software on the black BT Vision+ box all was well, but when they got upgraded to the New Look software the box then stated that the signal was inadequate. I can only assume that the New Look software uses different tolerance levels when deciding whether a signal is adequate or not? I would have expected that all Freeview equipment would implement common standards and guidelines in this area?
So the general consensus from this forum has been:-
(a)  The black BT Vision+ box has two tuners so requires a stronger signal (I'm not sure how true that really is).
(b)  The black BT Vision+ box has always had fussy tuners that require a stronger signal than most TV's (possibly due to (a) )
(c)  The New Look software seems to have made the black BT Vision+ boxes even more fussy about the signal strength.
I'm no expert either, just reporting what is commonly reported/discussed on this forum.