RF Transmitter Circuits
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After we published the original Li`l 7 AM Transmitter plans, fellow experimenter Scott Todd sent us information about his design for a similar portable, battery-powered transmitter. -Original Message- From: Scott Todd Sent: Wednesday, April 12, 2000 8:58 AM.... -
This is an 8MHz amplitude modulated (AM) radio transmitter, which I built mainly for work, and also as an exercise in electronics (it is the first RF transmitter I`ve ever built). We wanted to have a simple radio transceiver design at our disposal for some.... -
Welcome to the weblog where we discuss about electronic circuits schematics, PCB design, diy kits and electronic projects diagrams. The FM transmitter circuit is using NPN transistor 2N2222. The L1 and C1 producess necessary oscillations Q1. The collector.... -
The circuit is basically a radio frequency (RF) oscillator that operates around 100 MHz. Audio picked up and amplified by the electret microphone is fed into the audio amplifier stage built around the first transistor. Output from the collector is fed into.... -
L2 RFC (resistance 1MOhm with wrapped around her inductor of enough coils from fine isolated wire. Scratch of utmost inductor and you stick in utmost the resistance making thus a parallel L-r circuit. ) With their C7, C8 we adapt the resistance of aerial.... -
This FM transmitter electronic project works in FM band and it has a transmission power around 250mW. This FM transmitter electronic circuit is very simple and is based on some common transistors and electronic parts. T1 transistor can be a BC107, BC171 or.... -
The BA1404 fm stereo modulator Ic contains all parts needed to design an simple high efficiency stereo transmitter circuit, it contains a stereo modulator that creates stereo composites signals, an FM modulator that creates FM signals and a RF amplifier. The.... -
L2 RFC (resistance 1MOhm with wrapped around her inductor of enough coils from fine isolated wire. Scratch of utmost inductor and you stick in utmost the resistance making thus a parallel L-r circuit. ) With their C7, C8 we adapt the resistance of aerial.... -
The circuit of the transmitter is shown in Figure 1, and as you can see it is quite simple. The first stage is the oscillator, and is tuned with the variable capacitor. Select an unused frequency, and carefully adjust C3 until the background noise stops (you.... -
Cool little FM transmitter. Suitable for study purposes, you can use the RF part of this transmitter easily for your projects. However, unless you know how to build a serial data link and connect this LPFM transmitter to a PC or a microcontroller, you won`t.... -
Tetsuo Kogawa`s circuit is pretty well documented, but not in conventional schematic form. I decided to enter it into LTSpice to see what it could make of it, and decided to go ahead and put the schematic online here, with perhaps a few comments: I`ve set.... -
Let`s construct a low-power FM transmitter using surface-mount devices (SMD) that will be received with a standard FM radio. Soldering surface mounted devices is not so hard and actually is quite easy. There are many designs for small FM transmitters but.... -
This is a 6m band transmitter RF power amplifier (50 MHz) with 100W output. It used with my FT-736R and drive from 10W for the 6m SSB DX. The Building information comes from Japan CQ Magazine. The Toshiba RF bipolar power transistor is used in it. If you.... -
This is a Mini MW (Medium Wave) Transmitter circuit. This circuit consist of combination of transistors SA103 and SA101. Those transistors is used as oscillator... -
The most important part of this 88-108 transmitter is the Colpitts oscillator. C3,C4,C5,C6,CD1-CD2 ans L1 determine the transmission frequency. The RF Osci... -
The AM Transmitter circuits in two and a half, audio amplifier and an RF oscillator. The oscillator is built around Q1 and associated components. Tank circuit L1 and VC1 is melodious from about 500kHz to 1600KHz. These components can be used from an old MW.... -
This FM transmitter circuit is small, similar to our previous single chip FM? transmitter, but this FM transmitter is monophonic. You can see in the circuit`s... -
Here`s BH1417 USB FM Transmitter with built-in PLL circuit. Its low-frequency signal is converted into high-frequency, which can take any audio device with FM radio (stereo, car CD, MP3, DVD player, etc.), as a normal radio station. Transmitter power is.... -
Current loop interface has been widely used in industrial environment because it`s robustness. Noise resistance and fail detection capability? made it suitable... -
This is a FM Transmitter circuit. This circuit uses logic gates. This transmitter circuit has a RF oscillator. This oscillator uses 10.7Mhz ceramic filter and... -
Take a look at this fm spy transmitter which can be used as a bug transmitter or as diy fm bug too. It uses a single IC 74F13, one coil, a capacitor, one t... -
In this circuit, a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a class C amplifier configuration. The oscillator frequency can be either fixed by a crystal or made adjustable (VFO) with a.... -
There are not many AM transmitters that are easier to build than this one because the inductor is not tapped and has a single winding. There is no need to wind the inductor as it is a readily available RF choke (eg, Jaycar Cat LF-1536). To make the circuit.... -
An output of 4 mA to 20 mA that is linearly proportional to the input voltage is provided by the current transmitter on figure below. Line rejection is... -
This house FM transmitter for your stereo or any other amplifier provides a good signal strength up to a distance of 500 meters with a power output of abou... -
This easy to build FM transmitter bug can transmit voice to exceptionally good range. Tune trimmer to hear the signal to your near radio. Transmitter frequency range is 88-108 MHz. Max current consumption is 30mA. You can power the fm transmitter bug with a.... -
Simple FM Transmitter Circuit This simple FM transmitter circuit was built using a transistor with a transmission distance of about 300m around your home. It`s... -
This is probably the simplest radio transmitter that you will find anywhere. It has a total of five parts and can be constructed into a very small space. It is great for science fair projects or other science related projects where short range transmission.... -
This small video transmitter is very usefull for video surveillance on short distances ( up to 100m ) equipped with a black and white or infrared camera mo... -
A high quality stereo FM transmitter circuit is shown here. The circuit is based on the IC BA1404 from ROHM Semiconductors. BA1404 is a monolithic FM stereo modulator that has built in stereo modulator, FM modulator, RF amplifier circuitries. The FM.... -
The circuit was constructed using a few components that is powered by a 9 V battery for sensing the presence of bugs transmitting within the frequency mod... -
Here is a simple USB FM transmitter that could be used to play audio files from an MP3 player or computer on a standard VHF FM radio by connecting it to an...
New Circuits
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This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of.... -
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is.... -
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to.... -
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This.... -
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the.... -
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,.... -
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the.... -
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power.... -
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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