I know the K1 is ancient history, built K1-4 s/n 2258 sometime ago. Have worn out and replaced a VFO pot and two headphone jacks. Even with a K2 sitting on the desk, still very much enjoy using the K1 QRPp either inside or out on the patio or out in a park. A classic IMHO, too bad the 4 band filter board is no longer available. 73, Curt KB5JO