In my first post about creating a simple AM transmitter I have already told that how our society is obsessed with new time technology like social media, internet, TV, etc. These thing have big problem which is that they are mass media and a simple cause in a far land can cause the whole system to trip. We all know how much important communication is.
Suppose a condition comes where there is no chance of cellular network let alone internet. The best thing you can do is use AM transmitter and receiver. If you have a ready made one for emergency that is good but if not this is very simple method to build an AM Radio receiver. If you have energy, and are thinking of possibilities in future, you should definitely build one. Not only it can be used for emergency, it can be a fun project to play with your children, neighborhood, friends etc. I used to play with transmitters and receivers to play with friends by using them as our comm during operation in games. All you need is common electronic items, some skill, knowledge and great will power.
Thing you need:
Copper Coil and Capacitor
4) Connecting wires
I bought every thing from local and actually historical place of Kathmandu. This market is in Bangemudha on the way to Nara Devi from Ason’s Annapurna Chowk. Please see and follow the below given schematic diagram:
First of all for receiver, antenna is most important which can be a insulation less wire or iron rod of any length(longer the better). End of antenna goes to wire that connects the copper coil. The coils other ends have capacitors in parallel as shown. One of them is a variable capacitor.
We have actually set up a tuner (resonator) for maintaining the required frequency. The diode used is a germanium diode and the resistor is a 150K Ohm resistor. When the resonator is used in a specific condition the resonance happens and the circuit will provide clear sound which is required by us.