The electromagnetic fields measured on the ERG satellite are presented and their comparative analysis with measurements on the WIND satellite is carried out. The possibility of capturing auroral kilometric radiation (AKR) into plasma channels, which was first discovered on the ISEE satellite, has been confirmed. Plasma inhomogeneities, formed with an increase in geomagnetic activity, are extended along the magnetic field and form channels along which the radiation propagates. The trapped radiation spectrum is distorted because of the relative position of the source and channel at low frequencies. The distortion of the AKR spectrum at high frequencies is related to the frequency dependence of propagation conditions in the channel. Asymmetry of the processes of formation of plasma channels and AKR sources in the northern and southern auroral regions is found.