I've decided to try to get a few train signals installed on both loops of my layout, but have run into some confusion. Looking at this page it says each block needs to be 35-50 scale feet in length. That would be a pair of ir sensors and an TS2 every 6 inches, which seems a bit excessive! Also their diagram shows a signal at the the end of each block.......so there has to be a signal tower every 6 inches, or can you put them only where you want them? I must be missing something here....