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How does a Radio Work – Circuit Schematic
How does a Radio Work
Thompson and Braun had both discovered or invented the Cathode Ray Tube in 1897 the Amplifying Triode wasn`t invented till 1906 by Lee de Forest. The Diode valv...
RF Module Interfacing Circuit Example – Circuit Schematic
RF Module Interfacing Circuit Example
I am posting here a circuit example for interfacing RF module using HT12E/D encoder decoder pair. The circuit attached here can be used to transfer data using t...
VLF Whistler Reception – Circuit Schematic
VLF Whistler Reception
Natural Radio" is simply radio noise with natural origins, mainly lightning, but also clouds of ions interacting with the earth`s magnetic field. Nearby lightni...
Crystal Radio Circuits – Circuit Schematic
Crystal Radio Circuits
The crystal radio gets its name from the galena crystal (lead sulfide) used to rectify the signals. A "cat`s whisker" wire contact was moved about the surface o...
Low Frequency Antennas – Circuit Schematic
Low Frequency Antennas
Home-made antennas can greatly improve the performance of AM and FM radios, short-wave receivers, and scanners. If you are a talk-radio fan then experiment with...
AM band Transmitter – Circuit Schematic
AM band Transmitter
The picture to the left is a high quality radio transmitter for the A. M. broadcast band. The transmitter legally operates with "micro-power" and will not set a...
Amazing All-Band Receiver – Circuit Schematic
Amazing All-Band Receiver
The Amazing All-Band Receiver is basically a diode detector followed by a high-gain audio amplifier. This is not a multi-band receiver; it picks up everything a...
Micro Power Transmitting Station – Circuit Schematic
Micro Power Transmitting Station
The purpose of this report is to provide background and findings or our senior project. We will discuss four steps that we used to complete our final project. T...
Wideband FM Jammer – Circuit Schematic
Wideband FM Jammer
This wideband jammer simultaneously blocks all transmissions within a desired band typically by sweeping  across the desired band to be blocked, starting at t...
USB Mono FM Transmitter – Circuit Schematic
USB Mono FM Transmitter
This small FM transmitter with a range of about 50 meters designed for connection to the USB port. With lots of mini-transmitters then you have a comprehensive,...
Voice Link Over Spread Spectrum Radio – Circuit Schematic
Voice Link Over Spread Spectrum Radio
Until quite recently spread spectrum techniques were almost exclusively in the military domain. Their use in GPS and the latest cellular phones will be followed...
Voyager MkII Page 1 – Circuit Schematic
Voyager MkII Page 1
This is one of the smallest and neatest FM transmitters to be presented as a construction project and it has the advantage of being available as a complete kit ...
Crystal Locked FM Bug – Circuit Schematic
Crystal Locked FM Bug
A number of simple FM devices, (without the use of a crystal) and showed how the power and frequency depends on a number of factors including the voltage of the...
Installation of IFD in Kenwood TM455 – Circuit Schematic
Installation of IFD in Kenwood TM455
Feed the cable through some hole in the chassis to the opposite side There, between fan and rear panel, you may install the IFD board upside down. Use a thin an...
RF Circuitry Links – Circuit Schematic
RF Circuitry Links
The 7th overtone of 18mhz (17m) is 144mhz (2m) smack dab in the CW region. Icarus a HAB project run on advertising revenue that seems successful and has launche...
Ridiculously Simple AVR AM Radio Transmitter – Circuit Schematic
Ridiculously Simple AVR AM Radio Transmitter
Create a rapid transmitter/receiver pair that anyone would have around their house. I decided that AM or FM radio would be good since everyone can receive that,...
Microcontroller Clocking a Transmitter? – Circuit Schematic
Microcontroller Clocking a Transmitter?
The core of any transmitter is usually an oscillator circuit, and in simple transmitters (i. e. , QRSS devices), it`s often a crystal. Frequency adjustment is a...
Puxing 777 Radio Headset Schematic – Circuit Schematic
Puxing 777 Radio Headset Schematic
A speaker/microphone/transmit button circuit for the puxing 777 which probably works for all puxing radios. I decided to reverse-engineering an earphone/microph...
Stormwise VLF Radio Electronic Project – Circuit Schematic
Stormwise VLF Radio Electronic Project
This radio receiver built on a piece of wood uses only 5 transistors but will receive longwave beacons and VLF beacons, depending on the antenna unit connected....
Crystal Radio Antenna Preamplifier – Circuit Schematic
Crystal Radio Antenna Preamplifier
Adapting one of my failed Tesla coils into a crystal radio set to show the neighborhood kids. I`ve run into the #1 problem everyone faces not enough antenna to ...