Superheterodyne receiver circuit for an electrical radio clock

摘要

The invention relates to a superheterodyne receiver circuit for an electrical radio clock. The superheterodyne receiver circuit is essentially characterised in that two switchable ferrite rod antennas which are disposed so that they are offset through 90 DEG in relation to one another, a controllable antenna amplifier and an electronic quartz filter are provided in the input part and a crystal-controlled oscillator is provided in the mixing part. The antenna amplifier is controlled by means of the control voltage of the demodulator stage. An intermediate frequency in the order of magnitude of the lower audio-frequency range is used.