•  
  •  

Powerful AM transmitter

The circuit for a powerful AM transmitter using ceramic resonator/filter of 3.587 MHz is presented here. Resonators/filters of other frequencies such as 5.5 MHz, 7 MHz and 10.7 MHz may also be used. Use of different frequency filters/resonators will involve corresponding variation in the value of inductor used in the tank circuit of oscillator connected at the collector of transistor T1.
The AF input for modulation is inserted in series with emitter of transistor T1 (and resistor R4) using a transistor radio type audio driver transformer as shown in the circuit. Modulated RF output is developed across the tank circuit which can be tuned to resonance frequency of the filter/resonator with the help of gang condenser C7. The next two stages formed using low-noise RF transistors BF495 are, in fact, connected in parallel for amplification of modulated signal coupled from collector of transistor T1 to bases of transistors T2 and T3. The combined output from collectors of T2 and T3 is fed to antenna via 100pF capacitor C4.
The circuit can be easily assembled on a general-purpose PCB. The range of the transmitter is expected to be one to two kilometers. The circuit requires regulated 9-volt power supply for its operation. Note: Dotted lined indicates additional connection if a 3-pin filter is used in place.

If there are any problems please contact webmaster@electronic-circuits-diagrams.com

Please share & like

LOT OF 5 NEW BOURNS CT-26-6A POTENTIOMETER 10 TURNS 3 DIGIT TURN-COUNTING DIAL
$500.0 LOT OF 5 NEW BOURNS CT-26-6A POTENTIOMETER 10 TURNS 3 DIGIT TURN-COUNTING DIAL picture
(15) B500K 500K Linear Taper Rotary Potentiometer Guitar Knob Pot 3 Pin 16MM
$10.0 (15)  B500K 500K  Linear Taper Rotary Potentiometer Guitar Knob Pot 3 Pin 16MM picture
DC 6-60V 0A-30A PWM Adjustable Motor Controller Start Stop Switch Potentiometer
$11.07 DC 6-60V 0A-30A PWM Adjustable Motor Controller Start Stop Switch Potentiometer picture
5 Pcs 6mm 15/64" Shaft Hole Dia Potentiometer Pot Pointer Knobs Caps TB
$1.54 5 Pcs 6mm 15/64
B50K 50K Ohm Dual Linear Taper Volume Control Switches Potentiometer SwitchZ0JHW
$0.99 B50K 50K Ohm Dual Linear Taper Volume Control Switches Potentiometer SwitchZ0JHW picture