Science Buddies: "Ask an Expert"

I'm doing a soldering project to build an AM/FM radio and in my research the topic of making a metal detector using a radio and calculator came up. I understand the radio's purpose in the metal detector, but what properties of the calculator help make a metal detector work?

Hi - this forum is for K-12 students doing a science fair project. However, there are other forums online where you can get help with electronics projects as an adult, such as Stackexchange or Reddit. If you post there I would recommend including more details, like links to project instructions or circuit diagrams you are following, because they will need more information in order to answer your question.