I understand that there is still an issue with unicable and recordings. The solution seems to be to keep the physical tuner, say Tuner A, powered on.

Is there a simple "cable power injector" solution? A simple DIY one as shown here - http://www.satcure.co.uk/tech/dc_inserter.htm

I'm assuming that the LNB is to the left. Power could be simply taken from the 12v supply to the receiver. Then whenever power to the receiver is on, the LNB is also getting power.

And I now think that the splitter I bought is actually a power inserter:

https://www.toolstation.com/procepti...plitter/p66100

DC goes in at the top, right hand bottom to LNB and left hand bottom to receiver.