Hello , dear readers this time i am here with a simple but powerful FM Mic . This is very very easy to operate and it's rage is above 500 meters under normal circumstances . It can be listened from and FM radio or even from you TV too. It's frequency varies from 87.5 to 108.0 Mhz that depends on how you make the inductor of this mic but one i have has a frequency of 94.4 Mhz . But it is easy to build and it's cheaper too rather than buying from stores it it's also very compact!
Step 1: Stuff You Will Need!
You don't need much stuff but a part of this circuit which is the inductor is quiet difficult to make !
This * 1 or two sign states the quantity of the component either 1 or 2.
1. Transistor BC 547 * 2
2. Transistor BC 557 * 1
3. Ceramic capacitors : 10pico farad * 1 (12 "These are the codes written on the body of the ceramic capacitor" ) , 2.7pico farad (2.7 or 2p7), 1 nano farad * 2 (102) , 10 nano farad * 2 (103).
4. Electrolytic capacitor : 22uf * 1 .
5. Resistors : 4.7 k *1 , 2.2 k * 1 , 1Mega ohm * 1 , 330 ohms * 2 , 47 kilo ohms * 1.
6. Electric microphone not the dynamic one * 1.
7. 9 volts battery * 1 , battery holder.
8. Inductor : 6 Turns over a 6mm air core of 18 gauge!
9. And last but not the least some basic electronics equipment like soldering iron ETC.
Step 2: Circuit Diagram!
Here's the circuit diagram!
An advice if you are a amateur in electronics but know how to make circuit i suggest you to handover the inductor making task to a good electrician.
Step 3: Fitting
This is also an important part !
You cannot use this circuit openly without proper casing you could put it in a small bottle or whatever you find better and you do have to care about the antenna the antenna should be half a meter long wire coiled like shown and i advice you to touch the bare antenna this improves the range and audio quality. And you have to cover the mic with some soft cotton cause this microphone is too catchy it will blow you ear because of the boooooyaaaannnngggggg! and if you even say some thing without the soft insulation the voice quality will go so it's very very important to insulate the mic ! And after putting some soft stuff cover the upside with a soft puffy foam as i had done.
Step 4: Setting Up for Use!
Once you have made it it's the time to test it using your FM radio player the frequency could lie between common radio frequency as you can see i used my mobile phone's inbuilt radio to test it and it worked! That's all hope you will enjoy it!
And please care to vote for me please!