The radio astronomy experiment on Helios A and B /E 5c/

The NASA Goddard Space Flight Center radio astronomy experiment on Helios, identified as Experiment 5c, has sixteen observing frequencies over the range of 26.5 to 3000 kHz. The antenna consists of two extendible 15-m booms, forming an electric dipole, two high-impedance preamplifiers located at the root of the booms, and the 16-channel radiometer. Important information about propagation conditions, such as absorption, scattering and refraction, are expected from observations of radio emission regions at distances between 1 and 0,3 AU.