extra cable boxes

[TheCoder]

If you've got a modem as well thats 6 devices - the line is really only designed to run 4 loads.

It may work ok, but you are pushing the line driver beyond its recommended load.

As a general rul of thumb splitters will reduce the signal by 1/NoTaps, so a 5 way splitter will supply approx 1/5th of your full signal to each device (regardless of whether you use the tap or not). That may sound a lot but the dynamic range of the equipment will probably handle it IF your signal is relatively high to start with.

You'll probably have more success with a box that has a tuner more suited to use in the UK (ie KryptView) rather than something like a Dbox/Dreambox.

An amplifier may help if your signal goes too low but only if you have very low signal-noise ratio on your incoming signal. If the noise is quite high then an amplifier will simply amplify the noise possibly causing it to swamp any signal.