Tone squelch circuit

Abstract

Abstract PURPOSE:To make the operation high-speed and stable, by providing a gain control circuit, a band pass filter, a detecting circuit, and a switch circuit in series and by controlling the gain of the gain control circuit by the output of this filter. CONSTITUTION:A gain control circuit GC is provided in the input side of a band pass filter BPF, and the gain of the gain control circuit GC is controlled by the output obtained by rectifying and smoothing the output of the band pass filter BPF by a detecting circuit REC2. Thus, the output of the band pass filter BPF is always held in a constant level. However, it means a stationary level, and the delay of an automatic level control loop is utilized positively in the rise part to make the output large.

Inventors

• 👤 Yuji Nishi

Bibliographic Details