My elderly father is having issues with his new Sky Box.  Sounds like pixelation and possible rain fade.

I just had a look in the Diagnostic section and under Signal and Tuner Status I can see a Signal Quality of 8.2dB and a small blue line.

The old boxes had Quality and Strength as a percentage.  Can anyone tell me what a good dB should be for Signal Quality on the new Sky Box? 

Thanks