Thursday, August 4, 2011
Low Cost Powerful AM Transmitter (13Km)
This is a simple AM Transmitter Circuit, but Its very powerful one. It can transmit SW range signals within 13Km circular area. Use external antenna for best results. I recommend you to use 12V battery as the power supply. If you hope to use 12V AC-DC adapter, you may want to generate a very smooth DC out put using stabilizer, unless It will generate low frequency hum when listening to radio out put. Better to read following instructions before assembling the circuit.
>> L1 Coil Use 22SWG copper wire and wind 10 turns, Insert a ferrite rod in to the coil. see figure 1.
>> L2 Coil
Use 22SWG Copper wire and wind 10 turns. Don't use a ferrite rod. Coil diameter is 0.6 cm ( 1/4' ).
>> X-tal (Crystal)Use 4.4333MHz crystal.
>> Transistor pin identification
Use following diagram for identify the pinout of BFY50 transistor.
NOTE : I strongly recommend to use heat sink for the Transistor. unless it will die within few minutes. And also never apply the power to circuit without connecting Antenna, It also causes to harm the Transistor.
>> Antenna (Use this cable for best results, otherwise you can use any type of copper wire(at least 2meters long))
Warning
: This project just for educational purposes only. If you want to use
this circuit for long time you should get a permit.
This is a simple AM Transmitter Circuit, but Its very powerful one. It can transmit SW range signals within 13Km circular area. Use external antenna for best results. I recommend you to use 12V battery as the power supply. If you hope to use 12V AC-DC adapter, you may want to generate a very smooth DC out put using stabilizer, unless It will generate low frequency hum when listening to radio out put. Better to read following instructions before assembling the circuit.
>> L1 Coil Use 22SWG copper wire and wind 10 turns, Insert a ferrite rod in to the coil. see figure 1.
>> L2 Coil
Use 22SWG Copper wire and wind 10 turns. Don't use a ferrite rod. Coil diameter is 0.6 cm ( 1/4' ).
>> X-tal (Crystal)Use 4.4333MHz crystal.
>> Transistor pin identification
Use following diagram for identify the pinout of BFY50 transistor.
NOTE : I strongly recommend to use heat sink for the Transistor. unless it will die within few minutes. And also never apply the power to circuit without connecting Antenna, It also causes to harm the Transistor.
>> Antenna (Use this cable for best results, otherwise you can use any type of copper wire(at least 2meters long))
