A 2-4 kMc sweep-frequency receiver

To study another octave of the solar radio-frequency spectrum, a new superheterodyne receiver using a video-frequency IF was developed. This receiver scans the 2000- to 4000-Mc octave in 0.1 sec by using a backward-wave oscillator as the local oscillator. A carefully designed balance mixer converts the incoming signal directly into a video signal, where it is amplified and displayed as an intensity-modulated trace on a high-resolution cathode-ray tube. The receiver has an average noise figure of 13.0 db, and a total gain variation of\pm2db over this octave. The receiver features power output stabilization of the local oscillator, a 2000- to 4000-Mc noise source, and highly stable video amplifiers.