August 31 More signals by John Purbrick. Dissatisfied with the first scratchbuilt model (see April), he bought some photo-etched ladders and platforms and made this (we now have 3 of them). Very fragile, so use some care! It’s mounted on little custom-made circuit boards connected by wires in sockets: if it’s knocked over, the hope is that it can just be plugged in again.