A common example of the D layer in action is the disappearance of distant AM broadcast band stations in the daytime. Source: Internet
A new digital radio technology, Digital Radio Mondiale (DRM), is expected to improve the quality of shortwave audio from very poor to standards comparable to the FM broadcast band. Source: Internet
During the winter months of the Northern or Southern hemispheres, the AM/MW broadcast band tends to be more favorable because of longer hours of darkness. Source: Internet
For example, a typical AM broadcast band receiver covers 510 kHz to 1655 kHz (a roughly 1160 kHz input band) with a 455 kHz IF frequency; an FM broadcast band receiver covers 88 MHz to 108 MHz band with a 10.7 MHz IF frequency. Source: Internet
If the AM broadcast band receiver LO were set at 1200 kHz, it would see stations at both 745 kHz (1200 455 kHz) and 1655 kHz. Source: Internet
In the US AM broadcast bands this occurs at 10 KHz, which is the US channel spacing for the AM broadcast band. Source: Internet