Pruning redcurrant bush advice

I have a five year old redcurrant bush that has become unproductive this last two years despite me pruning it to develop fruiting spurs as advised in RHS and other books. It is in a raised bed and, because I have added compost etc, it isn't on a single leg any more and now looks the same shape as my blackcurrant bush. It has its main framework of old branches plus plenty of new growth from the base and some on the stems too. I have assumed that the side stems from the main branches is the bit you prune back to develop the spurs but I could have got it wrong and maybe it's the side growth from these side stems that you prune back. Help much appreciated as my OH didn't have any berries to make his redcurrant jelly for Crimbo - disaster! 

Redcurrents bear on "old" wood. Just wondering if you have pruned out the old wood to leave new growth that will not bear for a year or two.

The bush should have a mix of old and new wood, I guess that when the older wood ceases being productive that it is pruned out and a new brach is allowed to grow to replace it. Meanwhile the other brances will be producing.

I have 2 redcurrents and (being idle) rarely prune, they are full of berries, but it is all on old wood not new growth.