OK - long message, sorry

OK- first things first. Do you have a signal check on your TV ? If so, have a look at both strength and, more importantly quality of signal. The vital component is a good signal to noise ratio when receiving digital transmissions. If the signal quality is very good, along with strength, you may have a problem within the digital receiver in your TV.
If you have no way of checking, the next step is your loft booster. It may be faulty, but most likely it has a quite high noise figure. That will be quoted on the spec label attached, as well as in any docs that go with it. Expect a figure of around 4 – 5db noise figure. You really need a masthead amp (MHA13U from Maxview.co.uk is perfect) with a 2db noise figure and 13db gain to overcome cable / splitter loss.
If you have a separate signal splitter it must be inductive – an inductive splitter will have a signal loss in each leg of about 3.5db, where a resistive one will have 9db loss!
Thus if you are already in a marginal signal area, and have the correct aerial, one or more of the above can be altered to give you the edge.
The LAST area to try is the aerial. Check out your aerial, is it correct for your region since digital TV started ? Some aerials are grouped and BBC may be on the edge of your aerial reception frequency band. To find out, check the colour of the bung in the end of the rod that holds all the small dipoles – red = group A, green is group C/D, black is wideband (all groups). If you have a wideband aerial but your channels are all in Group A or Group C/D you need to consider a high gain grouped aerial which can win you back up to 5db of pure signal.
Good luck – you can always ring Mark at Maxview on Customer Servs, who will be glad to help. I worked there for 10 years designing and building kit for digital reception, so I know him well.

Posted By: Cannydc, May 13, 11:35:55