FK718 DSP AM/FM RADIO RECEIVER KIT WITH ANTENNA

This circuit is a DSP (Digital Signal Processing) radio circuit that uses
selective adjustment. Stations by changing the voltage which is different from
choosing a conventional station that uses adjustable the capacitance. This
circuit uses only one controller IC, can operate as AM and FM radio, so the
circuit can be easily built and assembled for newbies as well.
Technical data
- Power supply : 4.5-6VDC.
- Electric current consumption : 200mA. (max.)
- There is a switch to choose to AM or FM stations.
- Use adjustable resistors To adjust the station selection.
- Use adjustable resistor In reducing the sound acceleration.
- Use the DSP radio receiver IC with internal receiver and controller.
- Has a power amplifier within 0.6 watts at 6 volts.
- PCB dimension : 2.85 in x 2.21 in
How does 

The operation of this circuit Will be divided into 2 major parts, including
radio receiver and audio amplifier
Part 1: Radio Receiver Section. The core of this circuit is IC1, a DSP-based
controller. Its primary pin configurations are as follows:
- Pin 1 and Pin 2 are connected to the SW1 switch, operate as an option to
receive AM or FM radio stations.
- Pin 4 will be connected to VR1, operate as a pin for controlling radio
stations.
- Pin 16 is the signal output pin
- Pin 12 and pin 13 are connected to the crystal 32.768KHz to generate the
frequency for IC1.
- Pin 8 is the pin input of the AM radio receiver.
- Pin 6 is an RF input pin of the FM radio receiver, with TR1 transistor to
amplify the signal before entering this pin.
The second part, the amplifier will use IC2 as the amplifier. The operation
starts when the audio signal from pin 16 of IC1 arrives at pin 7 of IC2 through
the VR2 volume, which acts as a catalyst or reduce the said signal This signal
will be strengthened. Then output to pin 1 and pin 3 for the next speaker output.