Practical realization of simple radio receivers, as well as other simple electronic devices, can be done in many ways, as it was discussed in PE No.2. One of those is shown also in this number. That is construction of the detector receiver from pic.3.11, where some of the components are mounted onto the box walls (the variable capacitor, coil and the hubs), while other (the diode and two block-capacitors) are placed between them. With some skills, and by the aid of few smaller nails nailed from the inside of the front panel, a more complex device could be made, say, that from pic.3.12. But this solution would start looking as “the dead cockroach technique”, which will be discussed in the “Funniest Electronics”. The real solution is the PCB that can be made from the drawings that are given, or those you will draw yourself, together with the instructions given in chapter 5.1.There’s another option for practical realization. It is a universal PCB, that can be bought in the electronic components’ stores. There are more sorts of these PCB’s, and all of them have in common that the holes on them are drilled on the distance of 1/10 inch (R=2.54 mm).One of the universal PCB’s is shown on pic.5.27. It consists from a huge number of round copper isles, with hole in the middle. The components are being soldered first (resistors, diodes, IC’s, capacitors...), and then the component pins are connected by pieces of isolated copper wire, on the soldering side.As an example, pic.5.28 contains the photograph of the receiver from pic.3.21-a that is made with the universal PCB from pic.5.27. It can be placed into a box as on pic.3.21-c, except the box should be bigger, in order for the loudspeaker to.