Great starter Arduino project!
All-band receiver. Super-simple schematic. This would be a great build with your kiddos to get them into ham radio.
AB0L (Formerly N0KAI)
Kenwood TM-V71A, Kenwood TS-590S, Icom ID-4100A, Yaseu FT-891, TYT MD-UV380, TYT MD-380, Kenwood TH-D7A, BTECH UV-5X3, µBITX V5, µBITX V4, QRPGuys 40/30/20m DSB Digital Transceiver