A Coaxial Cable Delay System for a Synthesis Radio Telescope

A switchable coaxial cable delay system for path compensation in a synthesis radio telescope operates over the frequency band 15-45 MHz. The requirements of continuum and spectral line observations determine the system specifications. Diode switches include or exclude cables whose lengths form a binary sequence from 0.625 to 320 m. Cables are equalized to compensate for the effects of frequency dependent attenuation and of dispersion. A simple technique for dispersion equalization is described.