Please note that in the case of a very long antenna, when C1 of very small capacitance is being used, a hand made trimmer capacitor can be used. It is made by twisting two isolated wires, and its capacitance is changed simply by removing some wire from the ends. The component data is given on the electrical diagram and in table on the rightmost side of Pic.3.12. If you don't have a 100 pF capacitor (C2) you can put some of bigger capacitance, but you should then use smaller R1. The PCB layout is given on Pic.3.13. On 3.13-a is a picture that should be copied with the thin alcohol marker onto well cleaned copper side of the pertinax plate. Etching is to be performed then, as well as drilling the 0.8 mm holes, in the way that has been described in detail in PE2 issue (Practical realization of electronic devices). The component layout is given on Pic.3.13-b. The printed circuit is also visible on this picture, and that can be achieved by using vitroplast plate instead of pertinax. The look of board upon completion is on 3.13-c. Before soldering the wires that connect the variable capacitor, battery, switch etc. with the board, put some tin on the wire ends, using the calofonium or the tinol wire. You should by all means do this, especially if you 're not using the wire that is not pre tinned, in order to avoid cold solders, very unpleasant surprises that are hard to detect and locate. The layout of the entire receiver is given on Pic.3.14, in a scale 1:1. As in the previous receiver example, the coil is being glued to the top side of the box, over two small pieces of wood. The board is being tightened with a screw, that is screwed into a piece of wood being glued to the front end box plate. The battery is attached with a rubber band for the pieces of wood glued at the back plate of the box. We did this, however, only for the sake of having a clear and understandable drawing. Battery can be put inside the box in the same way as before, or some other way.