Am Transmitter Circuit Diagram

The first circuit is the muntz version of a common one tube transmitter using a 12be6 pentagrid converter a k a.

Am transmitter circuit diagram. In practise about 3 milliwatts into. Since its intended purpose was as a converter for superheterodyne receivers its output power capability is quite low. Mini am transmitter this is the simple and low cost am transmitter schematic diagram built using transistor bc109c. The transmission frequency can be adjusted using the variable capacitance c3.

The amplifier circuit consists of two of the mallory circuits connected in a push pull configuration with a coupling transformer acting as both. The circuit is in two halfs an audio amplifier and an rf oscillator. A generic printed circuit board i used radio shack s 276 159a but any general purpose printed circuit board will do. This low cost am transmitter is tunable from 10 to 15 mhz with the help of j gang condenser vc1 which determines the carrier frequency of the amplitude modulation transmitter in conjunction with inductor l1.

The circuit is in two halfs an audio amplifier and an rf oscillator. A one megahertz crystal oscillator this is a crystal clock oscillator such as those used in computers. Power the circuit using a 9v battery for noise free operation. The tank circuit l1 and vc1 is tunable from about 500khz to 1600khz.

It is illegal to operate a radio transmitter without a license in most countries. The oscillator is built around q1 and associated components. Here is a low cost good stability rf am transmitter which uses only one fet. Our transmitter will need these parts.

Circuit description the heart of this circuit is a fet bfw10 t1 which works as a feedback oscillator. Radio receiver working principle. Use a 200uh inductor for the l1 in the tank circuit. The circuit is in two halfs an audio amplifier and.

Am transmitter block diagram the transmitter s output amplifier circuit is shown in figure 1. This is the simple and low cost am transmitter schematic diagram built using transistor bc109c. The frequency of the rf signal can be determined by the oscillator coil l1 and variable capacitor vc1. These components can be used from an old mw radio if available.

This ircuit is deliberately limited in power output but will provide amplitude modulation am of voice over the medium wave band. There are many suppliers such as an audio transformer this is a 1000 ohm to 8 ohm audio transformer such as radio shack 273 1380. The frequency trimming can be done with vc2. In figure 1 there are three radio stations each broadcasting at a different wavelength each station is broadcasting a radio signal consisting of a carrier wave and an audio signal.

Station 1 is broadcasting at am 920 station 2 at am 1460 and station 3 at am 1040.