Abstract: A diaphragm for a speaker includes two portions. The first portion is made of metallic material for producing a high frequency tone. The second portion is made of a non-metallic material for producing a low frequency tone. The first portion is joined at a first peripheral edge to a voice coil while a second peripheral edge is joined at a first peripheral edge of the second portion to form the diaphragm.
Abstract: A frequency modulated (FM) transmitter for use in the 100 to 300 megacycle band is described having a low parts count topology. The disclosed topology requires the use of five tank circuits tuned to various frequency multiples of a crystal oscillator to achieve a twelve fold multiplication of the natural frequency of the crystal oscillator.