B
BlackMamba
Guest
Project by marcin_oizo
Source here
Radio is build inside a box for matches. It is based on two transistors (BC147 and BF194) and a handful of miniature elements. It is powered by a single battery R3. A coil has about 200 rolls to receive Warszawa 1 on the long waves. I live in Częstochowa and central station reception is good enough to keep track of football match.
The most troublesome was a impedance coil (it can be seen on the left side of box in a metal mug). The best is to wind it on a ferrite ring. If there is no such ring a ready made coil with large number of rolls can be used (eg. Intermediate frequency filter from old radio). All must be screened not to radiate to ferrite antenna (in my case it was mounted in a aluminium mug from old intermediate frequency filter).