Wiring Diagram

This Circuit of FM radio-controlled anti- theft alarm can be used with any vehicle having 6- to 12-volt DC supply system. The mini VHF, FM transmitter is fitted in the vehicle at night when it is parked in the car porch or car park.

The receiver unit with CXA1019, a single IC-based FM radio module, which is freely available in the market at reasonable rate, is kept inside. Receiver is tuned to the transmitter's frequency. When the transmitter is on and the signals are being received by FM radio receiver, no hissing noise is available at the output of receiver. Thus transistor T2 (BC548) does not conduct. This results in the relay driver transistor T3 getting its forward base bias via 10k resistor R5 and the relay gets energised. When an intruder tries to drive the car and takes it a few metres away from the car porch, the radio link between the car (transmitter) and alarm (receiver) is broken. As a result FM radio module gene-rates hissing noise. Hissing AC signals are coupled to relay switching circ- uit via audio transformer.

BOOSTER RADIO FM SCHEMATIC CIRCUIT DIAGRAM

Here is a simple circuit of an FM booster that can be used to listen to programmes from distant FM stations clearly. This amplifier will pull in all distant FM stations clearly. The circuit is configured as a common-emitter tuned RF pre-amplifier wired around VHF/UHF transistor Q1.

rangkaian boster radio penerima FM
Skema rangkaian boster radio penerima FM


2SC2570. (Only C2570 is annotated on the transistor body.) Assemble the circuit on a good-quality PCB (preferably, glass-epoxy). Adjust input/ output trimmers (VC1/VC2) for maximum gain.

This antenna radiates radio waves as strong to just two directions. The two parameters that need to be considered on an antenna is the polarization and penguatannya. Simply put, an antenna has a vertical polarization if the antenna is placed in a position perpendicular to the earth. Antenna with vertical polarization will produce radio waves with vertical polarization, too. In addition to vertical, there are also berpolarisasi horizontal antenna, the antenna plays when the field parallel to the earth.