Eeek!... I remeber that book when it was current. As you've probably gathered, the 'ladybird books' were aimed at children, and I think I had all the 'How It Works' series. [The one I particularly _disliked_ was 'How It Works -- The Telephone'. I could not understand that book. I couldn't understand it when I re-read it several years later. I finally understood it when I bought a copy of 'Telephony' about 10 years ago. 'Telephony' is a book that was used by telephone engineers in the UK, and contains complete schematics for telephone exchanges, etc). I realised why I couldn't understand the simpler books, far too much had been left out, so what remained made no sense. There is a danger in oversimplifying things. Another Ladybird book was called 'Making a Transistor Radio'. It covered building a crystal sed, adding a single transistor audio amplifier, then a second stage and a speaker, and finally replacing the detector with a regenerative stage. The final set was a 3-transistor AM receiver using a couple of OC71s and an OC45. I think just about every UK electronics enthusiast built that at one time or another. -tony

Hey guys, any advice apperciated. Recently picked up an Odyssey game system, and the contacts on the game cards (basicly big jumpers) that came with it appear to have begun corroding and forming greenish and white deposits. My concern is I don't want to use any sort of cleaner that will harm whatever material the surrounding pcb is made of (as it appears to be made out of an older, thicker material than most modern PCB's I see). Thanks! Marty P.S. - I also have another side project I'm working on. Does anyone have any suggestions on what grain sandpaper to use for sanding plastic consumer device cases (old game consoles, personal computers) for painting/restoring?