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In this Electronic Circuit Project , a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a class C amplifier configuration. The oscillator frequency can be either fixed by a crystal or made adjustable (VFO) with a capacitor/resistor combination. A 100pF capacitor is used in place of the crystal for VFO operation. Amplitude modulation is accomplished with a second transistor that controls the DC voltage to the output stage. The modulator stage is biased so that half the supply voltage or 6 volts is applied to the output stage with no modulation. The output stage is tuned and matched to the antenna with a standard variable 30-365 pF capacitor. Approximately 20 milliamps of current will flow in the antenna lead (at frequencies near the top of the band) when the output stage is optimally tuned to the oscillator frequency. Micro Power AM Broadcast Transmitter Circuit Diagram: A small 'grain of wheat' lamp is used to indicat...

The BA3822LS BA3822FS BA3823LS and BA3824LS are monolithic, five-point stereo graphic equalizer ICs. Each IC has two channels, and the five center frequencies for each channel are independently set using external capaci- tors. These ICs feature a wide operating power supply voltage range (VCC = 3. 5V to 14V), and are available in compact 24-pin SZI visit page. P and SSOP packages, depending on the type. This makes them an ideal choice for home stereo systems, Radio cassette players, and car stereos. The difference between the ICs is the amount of boost and cut control. Choose according to the requirements of your application By ROHM Co. Ltd. via next.gr Am Radio / Fm If Stereo System Ic

Introduction  Purpose of a communication system: convey information through a medium or communication channel. ◊    The information is often represented as a baseband signal, i.e. a signal whose spectrum extends           from 0 to some maximum frequency. ◊     Proper utilization of the communication channel often requires a shift of the range of baseband         frequencies into other frequency ranges suitable for transmission, and a corresponding shift back to     the original frequency range after reception. ◊    A shift of the range of frequencies in a signal is accomplished by using modulation, which is             defined as the process by which some characteristic of a carrier is varied in accordance with                 modulating (signal) ◊      A common form of the carrier is a sinusoidal wave, in which c...