Am Transmitter Circuit Diagram
The frequency of the rf signal can be determined by the oscillator coil l1 and variable capacitor vc1.
Am transmitter circuit diagram. 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. A generic printed circuit board i used radio shack s 276 159a but any general purpose printed circuit board will do. Since its intended purpose was as a converter for superheterodyne receivers its output power capability is quite low. This marvel of engineering is at the same time an oscillator mixer and amplifier all in one valve structure.
A one megahertz crystal oscillator this is a crystal clock oscillator such as those used in computers. Mini am transmitter this is the simple and low cost am transmitter schematic diagram built using transistor bc109c. These components can be used from an old mw radio if available. 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. Circuit description the heart of this circuit is a fet bfw10 t1 which works as a feedback oscillator. The frequency trimming can be done with vc2. The circuit is in two halfs an audio amplifier and.
This ircuit is deliberately limited in power output but will provide amplitude modulation am of voice over the medium wave band. Our transmitter will need these parts. 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.
In practise about 3 milliwatts into. The circuit is in two halfs an audio amplifier and an rf oscillator. Use a 30 cm long insulated copper wire as the antenna. 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.
Station 1 is broadcasting at am 920 station 2 at am 1460 and station 3 at am 1040. The tank circuit l1 and vc1 is tunable from about 500khz to 1600khz. Here is a low cost good stability rf am transmitter which uses only one fet. The amplifier circuit consists of two of the mallory circuits connected in a push pull configuration with a coupling transformer acting as both.
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. Am transmitter block diagram the transmitter s output amplifier circuit is shown in figure 1. It is illegal to operate a radio transmitter without a license in most countries.
Power the circuit using a 9v battery for noise free operation.