This circuit can measure signals in bands that depend on the coil. With a coil of 30 turns in the form of 5 mm with wire 16, signals can be measured in the ranges indicated in the diagram. The circuit is powered by a 9 V battery and the antenna is a telescopic type. Sockets are made on the first, second, sixth and twelfth turns of the coil.
| Clique na imagem para ampliar |
