Arduino projects. FM receiver / transmitter.

Friends! I made a new project with an FM transmitter and receiver at 433MHz. This time I needed two Arduino UNO boards, one Board I connected to the receiver and the other to the transmitter. But unfortunately it didn’t work right away. I didn’t know why it wasn’t working? It turned out the problem is in the antenna. The antenna needs to be set to half the wavelength. That is, half the wavelength of 34 cm. Does not make the antenna less than 34 cm! With an optimal antenna, the signal is transmitted very wel