Before revision: 175 kHz (early wide band and communications receivers before introduction of powdered iron cores) 260 kHz (early standard broadcast receivers) Copenhagen Frequency Allocations: 415–490 kHz, 510–525 kHz AM radio receivers: 450 kHz, 455 kHz (most common), 460 kHz, 465 kHz, 467 kHz, 470 kHz, 475 kHz, and 480 kHz.
After revision: , 250–270 kHz175 kHz (early wide band and communications receivers before introduction of powdered iron cores) 260 kHz (early standard broadcast receivers) Copenhagen Frequency Allocations: 415–490 kHz, 510–525 kHz AM radio receivers: 450 kHz, 455 kHz (most common), 460 kHz, 465 kHz, 467 kHz, 470 kHz, 475 kHz, and 480 kHz.