Thanks Mac and Keef. It's all coming back now, the loads needed to keep the PSU happy would be rather a burden to contrive, just to give me a bench PSU with two fixed voltages.
I used to use some CB radio power units for odd tasks. The voltage control was somewhat basic and I could put a pot in and control the v with that. They were well built and cost nowt as CBing lost its popularity. I never did purchase one of those all singing units with LEDs showing the current and voltage. They were always just that little bit too expensive.
I was lucky to have a good scope, which I got in exchange for rebuilding a Sony camera. 0 to 100 Mhz Iwatsu Sp? But I sold that when I was packing up my home.
All of this is old-hat now I suppose, as a humble PC can be made to do most measurements...and indeed record the data forever. One will have to see if the grand-sprog is really interested before making him the excuse to buy more toys.