Cell phone call detector

simple fm radio.mp4

future engineers

FM Radio Receiver

future engineers

This circuit was tested and worked properly!

This simple fm radio receiver circuit consists of a regenerative rf stage, TR1, followed by a two of three-stage audio amplifier, TR2 to TR4. In some areas 3 stages of audio amplification may not be necessary, in which case TR3 and its associated components can be omitted and the free end of capacitor C5 connected to the collector of TR2Radio Receiver Circuit Diagram

The critical part of the fm radio...

Aircraft / Airplane Radio Receiver

future engineers

The communications between commercial aircraft and the ground can be interesting, amusing and sometimes even disturbing. However radios that receive the approximately 220MHz to 400MHz band commonly used for aircraft (both military and commercial) are not easily found. And scanners can be complicated, large and expensive. With an easy to build circuit such as this one, everyone can enjoy listening in on these conversations.

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How to build the simplest FM transmitter?

This tiny transmitter has several "defects": smaller radius of the service area, lower quality of the sounds and the relatively unstable frequency. These can be considered as a compromise to easily have your own transmitter for the time being or as a more positive choice. These "defects" are only from the perspective of conventional transmission such as "clear stereo sound to receive anywhere"

Simple FM Radio Receiver

future engineers

This FM radio receiver circuit is very simple to build and is powered by just a single 1.5V battery cell. Receiver consists of a regenerative rf stage

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Super Simple FM Transmitter

 

FM transmitters can be complicated to build, but not this one — it’s about the easiest you can possibly make. And though the science of radio is well understood, there’s a magical, emotional quality about it that we don’t often stop to appreciate. You will not forget the first time you pick up a transmission broadcast from a device you soldered together, yourself, from a few bits of copper, carbon, plastic, and wire.  

 
I am indebted to Jim and Kat of Sonodrome for first introducing me to that experience, through this very circuit, which I first built on a pre-etched PCB from a kit they offered for sale as recently as 2011

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How does the fm receiver works

FM Receiver Circuit Schematic

  The oscillator is adjusted between 87 … 108 MHz with C5.

2 km FM transmitter
Description.

With a matching antenna, the FM transmitter circuit shown here can transmit signals up to a range of 2 kilo meters. The transistor Q1 and Q2 forms a classic high sensitive preamplifier stage. The audio signal to be transmitted is coupled to the base of Q1 through capacitor C2. R1, R3, R4, R6, R5 and R9 are the biasing resistors for the preamplifier stage comprising of Q1 and Q2.

Transistor Q3 performs

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Simple and powerful F.M. Receiver

Communication in F.M. band is easy, less expensive and has many more advantage. As we have already published Simple F.M. transmitter circuit in previous article. Now, here is a circuit diagram with description of Powerful F.M. receiver using single IC used to receive frequency range of 88 MHz to 108 MHz in F.M. band. You can also use F.M. receiver  circuit in radio, tape recorder, stereo etc.