When I looked into a making a cheapish broad band receiver, these lost out to the chip sets used for SDR. For an extra couple of bucks I got a USB dongle that tuned 26-1750Mhz versus a bare chip ...

Building radio receivers from scratch is still a popular project since it can be done largely with off-the-shelf discrete components and a wire long enough for the bands that the radio will receive… ...

Build a Battery Tester. An Arduino can be used to test the life of any battery with less than 5 volts, Boxall says. So, for a quick way to see how much juice your AAA, AA, C, or D batteries have ...