Radio project

The radio club nights of late have been occupied with the latest construction project, a radio receiver. Run by John. I have been taken through the first steps; understanding the circuit diagram, a lesson in solder (basically if your life depends upon it don't use lead-free solder, but wash you hands afterwards!) and then working in 'ugly fashion'.

What is this? I hear from the beyond the door... Well, it is a form of building a circuit with the use of copper plate and copper pads (insulated on one side with paper or fiber glass) and not being restricted by using a circuit board (PCB board with lines connecting parts up). The main copper plate is the earth and so any parts that need to be isolated from this are soldered on to the pads which are mounted on the plate. It apparently looks ugly, but I think it looks awesome!


The above image is the first evenings work. This flat board will have a vertical piece soldered at the front for switches and such like, so the copper plate was carefully positioned right at the edge of the wooden block. The plate was pre-drilled (thank you John) and so using a marker pen the holes, attaching the plate and capacitor, were marked down on the wooden block and drilled. Due to the nature of the wooden block forming a small mountain when drilling, Oi! first drilled with a small bit (not all the way through mind as this is purely to aid the working of screws) and then only slightly in with a larger drill bit to overcome the mound. There are four holes for the screws, one in each corner. Then three holes arranged at points of a triangle (for the tuning capaciter) and two for a brace for the capaciter. Just a note that the capaciter is absolutly brilliant! with very fine fins that glide between each other at the turning of the spindle. There are lovely cogs that gently spin as you do so and a tiny spring to prevent any bounce back as you tune back and forth.

With the use of a template for the copper pads, I was able to mark down in formation where on the copper plate they were best to go. So using a stanley knife and ruler a sheet of copper plate had been scored on both sides into 5mm strips. This was then snapped off using pliers and cut into small squares using some hard-core cutters (making sure not to let the pieces fly off). Using the good ol' super-dooper glue, these were fixed in place. Notice the longer strip for several connections and the small rectangle of holed board for the IC chip (more about that later).

So, there we are. I'm not sure if I can post the circuit diagram, best check in with John next week. Until then, over.