I read that you can attach a Sky HD box with expired viewing card to the LNB out from a Humax Freesat Box and receive the same channels as per the Humax master unit. Is this correct?

Pretty well - to be more accurate each box can only receive the same polarity and band as the other - it's really a pretty poor solution.

Thanks - if master unit is switched off we appear to get all channels on a spare Goodmans Freesat unit. If master is on then we have a Favourites list which will contain the channels available on one of the polarities.

Now off to Maplins to get some connectors and introduce the old Sky box to a guest bedroom!!!

I know it is not the best solution but it helps to prove a couple of things. Option is now to take another feed off quad LNB for upstairs of house aready wired on coax from central unit in loft.