What Must todo

AM Transmitter circuit 

To this powerful AM transmitters are huge, using ceramic tuning 3.587 mhz resonator and resonator filters are also sold with a value of 5.5 mhz, 7.7 mhz and 10.7 mhz. Distance transmitter range is approximately 2-4 km. the working principle of this circuit are filter resonator/ceramic filters raise the frequency of the value of the resonator filter.


This frequency is amplified by the transistor can be changed t1. Frequency so need C7 as a regulator / placement. sound signal superimposed over the audio transformer.frekuensi which awakened by resonator filters and t1 is fed to the next amplify strengthened so as to achieve the desired power passed to antenna. t2 and t3 as a buffer as a final power amp.

For AM radio because its hard to find IC ZN 414 then now could be replaced with the equivalent of IC MK 484. Frequency coverage between 550 kHz-1600 mhz, 3 pins of this IC include series of radio tuner, RF amplifiers, automatic gain control, the AM detector. The series voltage regulator or a power transistor made by BC 108B, 4diada IN 4148, 2k7, 820R, and the 10K trimpot, trimpot functions for selectivity of the controller of all series. Then we using a booster class A and class B amplifier for signal modulated not disappear.

Using TEA5551T monolithic integrated radio circuit can be designed a AM radio receiver circuit which is designed for use as a portable radio receiver with headphones . 

AM Radio Receiver Circuit diagram

The TEA5551T radio receiver circuit contains all is needed for a AM radio receiver circuit (a complete AM part and dual AF amplifier with low quiescent current).The TEA5551T support a input voltage range (VS) from 1.8 V to 4.5 V but the typical voltage is 3 volts .Because in most case we don’t find to buy inductors you need to build the inductors L1 , L2 , L3 . In the picture bellow you can see the construction data for these three inductors .