无线麦克风是一种便携式电子麦克风，它使用户可以将其声音传输到没有任何电线连接的放大器上，因此名称为无线麦克风。
Making a wireless mic at home can be real fun, here we learn one such simple project which can be used for recording and paying back your voice wirelessly.
介绍
通常在公共地址计划，舞台娱乐节目或各种形式的场合中使用无线麦克风和放大器单元，需要放大语音信号，以使其在更广阔的区域和距离上可听见。
但是，由于通常在说话时用手握住麦克风，因此该装置需要完全无麻烦，以便持有的个人能够自由地围绕前提移动。在本文中，我们学习了如何构建简单的无线麦克风电路，并准确地用于上述目的。
什么是麦克风
麦克风是能够将空气中的语音或声音振动转换为电脉冲的设备。它们通常用于公共地址和娱乐计划。
Here we learn a very simple way of making an FM wireless microphone circuit that requires no wires for the specified operation
旧类型的MIC类型将电线或电线从麦克风到放大器，使用户非常麻烦和不便。绳索曾经危险地悬在用户的腿上，使他容易陷入纠缠，甚至由于混乱而绊倒。
This led to the invention of much sophisticated wireless types of mics which became much comfortable to handle and use on any platform, moreover the distance of the user from the amplifier also was no longer an issue now.
然而,发明之后才可能发生the invention and improvements in the FM broadcast technology, because the wireless mic actually incorporated a small FM transmitter which sent the voice signals in the form of FM waves to the FM receiver before it could get amplified in to the loudspeakers.
These wireless mics are still being used effectively for the intended applications and have become quite indispensable with the specific users.
Though the device may look quite sophisticated with its operations, but did you know it is actually very easy to construct at home and therefore can be made by any electronic enthusiast?
It is definitely one of the best fun electronic projects as it not only provides thorough amusement while making it but can be proudly used by the constructor for displaying the impressive wireless transmission capabilities of the built device.
电路原理图
How to Make this Wireless Microphone Circuit
Let's try to understand how to build a wireless FM microphone circuit.
麦克风部分实际上是由一个小型FM发射器组成的，该发射器很小，以至于可以在较小的平方英寸的空间中容纳它，如果使用SMD制成，则可以在1平方CM的区域内制成。
实际上，由于所涉及的参数确实是灵活的，因此可以以多种不同的方式进行试验。忽略的功耗使我们能够使用按钮单元进行操作。但是，如果打算在长时间的语音传输中使用该单元，则铅笔单元将更加优选。
The main active part of the circuit is the general purpose transistor, while the other supporting passive parts are also very few making the item very compact as far as part count is concerned.
The circuit assembly strictly does not require a designed PCB, nope! And in fact is not recommended either. The whole circuit can be fitted over a small piece of veroboard, or probably if you have a good hand with soldering, you would be able to stitch the parts together over a thin piece of plastic or rubber strip.
The figure shown alongside illustrates the details of the transmitter part, all that’s required for completing the wireless microphone section. A plastic pipe or any similar enclosure may be used for housing the circuit along with the battery and the switch.
How the MIC Circuit Works
The transistor, the inductor and the relevant capacitors are mainly responsible for generating the FM carrier waves; the configuration quite resembles a Colpitts oscillator.
The capacitors C1, C2 and C3 mainly determine the oscillator frequency and can be altered for changing the reception positions over the FM receiver band.The MIC converts the voice signals spoken close to it into electrical pulses.
These electrical pulses hit the base of the transistor, which now suddenly functions as an audio amplifier, amplifying the signals at its collector arm.However since the tank configuration responsible for manufacturing the carrier waves is also included at the collector arm get influenced by these amplified voice signals.
现在，载波开始被构成空中音频传输的音频信号开始受到调节。
可以通过任何标准接收传输波FM radio receiver，或者，如果要与高功率放大器单元直接合作操作该单元，则可能必须使用集成的耳机插孔来构建FM接收器模块，以便允许使用套件中的放大器线进行轻松插件。
FM模块在市场上很容易获得，并具有预设，以进行必要的频率调整。
这些是非常小的PCB组件，具有内置预设和用于音量控制，音频和天线的离散输出。
The only section that does not become a part of these assemblies is the amplifier which any way we don’t need as the amplification function is primarily associated with the PA system where the FM module needs to be fixed through the relevant LINE input sockets.
The FM module can be easily accommodated inside a small plastic square box with the embedded large jack protruding out of the box and also the antenna in the form of a neatly wrapped flexible piece of wire.
However for hobby purpose you may use your home FM radio for the receptions.
测试和设置麦克风发射机
Once the transmitter is built, it may be tested with the following few simple steps:
Connect a 3 volts supply to the circuit, preferably from two AAA pencil cells.
将FM接收器在发射器周围的某个地方放置在距离约2米的地方，然后开始调整接收器，直到找到收音机中的“嘶嘶声”突然变为零的“无效”点。
Now tap or speak loudly over the mic of the transmitter, which should be audible over the receiver clear and loud.
Now take the FM radio further away from the transmitter to about 10 meters and repeat the procedure by readjusting the tuning of the radio until the reception is crystal clear.
The testing of the wireless mic is done and it’s ready to be used.
House the e entire assembly inside a suitable enclosure as described in the above section and you are all ready with an efficient cordless microphone…….Well,.. now nobody can stop you from becoming a home-brewed karaoke rock star.
do you mean that the coil is not cylindrical but instead a square like in the picture?
that's correct
can you replace the components so that the frequency will broadcast on the lowest MHz of an fm radio. i think the lowest frequency is 85MHz or 87MHz?
you can do it by slightly tweaking L1 or C2. Either reduce the value of C2 or increase one turn on L1, or reduce the diameter of L1, or squeeze/press L1 sightly with your fingers to tighten the gaps between the turns.
嗨，这是阿斯温。如何转换该电路将信号传输到500meatter以上。你能帮助我吗。aswindcn@gmail.com. kindly help me guys.
Sir please tell me how to design inductor in detail. If small unwanted bend occurs is it effect our transmission ??
We cant make exact square inductor. Is it effect our transmission
电线形成的略有变化不会影响结果
Someone is doing this to me in my house and cars. Where is the best places to look to find it? I think it may be connected to my AC is that a good place to start?
请帮助：我有一个缠扰者在我的房屋和汽车上对我这样做。请帮助我知道在哪里寻找它。我认为它可能在我的AC周围。那是一个好地方吗？我会寻找什么？
you can use the following circuit for sniffing out the exact location of the transmitter bug:
//www.addme-blog.com/2012/01/how-to-make-ghost-detector-circuit.html
switch OFF mains power before you carry out the sniffing procedure with the assembled circuit so that mains disturbance does not hinder the procedures
In your Simple Wireless Microphone Circuit the signal is catch by mobile radio .
是的，它会在10米以内
CAN I USE MOBILE MIC IN THIS CIRCUIT
not sure about it
开关必须在电路中吗？
是的…。
thanks for replying me. Could you tell me what type of switch I can use ?
可以使用2N2222A晶体管吗？
you can use a small microswitch, push-to-On type.
2n2222 will also work
Can I power it w/ 9v battery? tnx
yes you can but it'll be unnecessary waste of energy…
先生，请逐步告诉我，要制作此设备需要哪些东西。请告诉我确定我可以从市场上购买的每个部分的名称。
Bilal，所有电阻均为1/4瓦5％，所有电容器均为圆盘陶瓷型，除1UF/16V非极性电解外，MIC是“ epentret MIC”
不错的一个……但是我希望麦克风将数据通过WiFi传输到受体……可能是手机，所以手机播放了。从麦克风到手机的数据？
sorry, that looks difficult, I have no idea about it
I'm not able to get a 1uF ceramic capacitor! Pls help me out…
1uF value is not critical, ceramic is not critical, you can use any capacitor between 1uF and 100uF
先生，我可以将手机连接到FM中播放音乐吗？
这意味着我可以将手机用作FM发射机
Manjunath, yes definitely you can do that! you can use your cellphone's headphone music output with the the above explained transmitter for listening to it on an FM radio wirelessly.
Sir was it possible to modify this to transmit fm radio wireless to distance around 2kilo meter if yes then how
Thank you
Manjunath, a two km design will require a lot more stages and complex set up, you can try the following circuit instead:
//www.addme-blog.com/2013/05/long-range-transmitter-circuit-2-to-5.html
i ve mini fm wirless microphone i wanna convert it to wired to use it to connect to pc
它可能有点复杂，最好购买带有3.5毫米插孔或USB的麦克风
可以使用直径1mm的搪瓷铜线作为线圈吗？
会做…
问候先生。我可以问一下此发射器的输出频率是多少？
本，这是我们在正常的FM无线电频段中所拥有的
嘿，兄弟..我可以更改我的麦克风transer表以接受所有FM接收器吗？
嗨，Brian，如果您的FM MIC能够与一个FM收音机一起使用，则意味着它将能够使用所有FM无线电，因为所有FM频段范围对于所有FM收音机都是相同的，对于不同的FM收音机，它不会有所不同
hi, so the fm coil need to be make to a square and attach it to antenna?
天线的长度是多少
你好, yes that’s right, the square shape is more convenient to build, the antenna could be a 6 inches long flexible piece of wire
你好
I am a doctor from Tamil Nadu. I am trying to make a small circuit to transmit a mic input to a bluetooth headphones. I want to attach the mic with amplifier to a traditional stethoscope head unit so that, i can hear the heart and lung sounds with a bluetooth headset. This is especially important in these Covid times, where the traditional stethoscope makes you lean close to the patient’s face making the doctor at increased risk of exposure.
嗨，为此，您需要以下两个项目：
Once the two are joined, then hopefully it may help you to achieve the requirement
Earlier i have a readymade FM mic that has almost same circuit. That uses BF494 instead of 547.
是的，上面的电路也取自现成的商业设计。