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RF Transmitter Circuits
RF Transmitter Circuits
VHF FM Transmitter MAX2606
If you want to be independent of the local radio stations for testing VHF receivers, you need a frequency-modulated oscillator that covers the range of 89.5 to 108 MHz ? but building such an oscillator using discrete components is not that easy. Maxim now has available a series of five integrated oscillator building blocks in the MAX260x series...
iPod FM Transmitter
Building your own ipod FM radio transmitter. It works quite easy, there is a power switch on the bottom to turn it on and tune your radio and transmitter to the right frequency. For the antenna you can use a copper wire of 70 cm. The range of this FM transmitter is about 100 to 150 meters (500 feet). With R5 you can adjus
Single Chip FM Transmitter For Short Range Application
The FM transmitter circuit here works in the broadcast band 88 to 108MHz, and can be used to broadcast audio signals for remote listening. The output power..
Temperature Sensor Current Loop Transmitter
LM134 makes a good temperature sensor because it has a highly linear output characteristic. Because it is a current output device and is therefore not affected..
Two Transistors FM Transmitter
Basically, this circuit is a radio frequency (RF) oscillator that operates around 100 MHz. The audio which is picked up and amplified by the electret..
LM10 Thermocouple Current Loop Transmitter
Current loop transmitter is the term associated with sensor system that is used in industrial 4-20mA current loop technology. This transmitter contain the..
4-20mA Current Loop Bridge Sensor Transmitter
Bridged resistive sensing elements is common in resistive type sensors/transducers. This sensor type need a biasing voltage to operate. LM10 provide low..
Small Broadcast-Band AM Transmitter
This AM radio circuit is a low power transmitter working on broadcast band. The simplicity is implemented using a single-transistor amplifier stage, and for..
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, and pondered how best to generate the necessary radio signal and modulate it appropriately. After a few LC oscillator designs, I thought about the RC oscillators built into most...
Rf Remote Control Transmitter Circuit
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 any distance records but, unlike simpler designs, the frequency stays put and the fidelity is excellent. Although the schematic looks somewhat complex, the circuitry is easy to build and adju
RF transmitter circuit
MC CONTROL TRANSMITTER
Free-running multivibrator keys power amplifier Q4 at audio role. Range is about 1 mile C6 tunes collector of oscillator to crystal frequency. -Texas lnstruments Inc. , "Transistor Circuit Design, " McGraw-Hill, N. Y. , 1963, p 361.
single-813 crystal oscillator transmitter
Here is the single- 813 crystal oscillator transmitter, designed by RCA and exhibited in their advertisement on the back page of a "QST" magazine in 1938, and published by RCA in their HamTips bulletin, vol. 1, no. 4, dated December 1938. This transmitter`s output is 150 watts of CW or 100 watts of plate-modulated AM telephony. It seems obvious
A Push-Pull Hartley VFO transmitter
This is a variation of the the Electron Coupled Oscillator circuit, pioneered by Dow in 1931. Dow`s ECO has the screen "grounded" for RF. In this circuit, because I am using filament-type tubes instead of heater-cathode types, and because I didn`t want to build or use a pair of filament chokes with this first
4 Transistor Transmitter
This circuit provides an FM modulated signal with an output power of around 500mW. The input Mic preamp is built around a couple of 2N3904 transistors, audio gain limited by the 5k preset. The oscillator is a colpitts stage, frequency of oscillation governed by the tank circuit made from two 5pF capacitors and the inductor. ( Click here for Colpit
An AM voice transmitter with variable tuning. The antenna circuit is also tuned and transmits via a long wire antenna. Please Note. It is illegal to transmit on the AM wavebands in most countries, as such this circuit is shown for educational purposes only. Please read the disclaimer on this site before making any transmitter circuit. It is illega
Surveillance Transmitter Detector
My site contains a few low power transmitters of one type or another, but until now no receiver. This circuit can be used to "sweep" an area or room and will indicate if a surveillance device is operative. The problem in making a suitable detector is to get its sensitivity just right; too much and it will respond to radio broadcasts, too little se
This small transmitter uses a hartley type oscillator. Normally the capacitor in the tank circuit would connect at the base of the transistor, but at VHF the base emitter capacitance of the transistor acts as a short circuit, so in effect, it still is. The coil is four turns of 18swg wire wound around a quarter inch former. The aerial tap is about
Long Range FM Transmitter
The power output of many transmitter circuits are very low because no power amplifier stages are incorporated. The transmitter circuit described here has an extra RF power amplifier stage, after the oscillator stage, to raise the power output to 200-250 milliwatts. With a good matching 50-ohm ground plane antenna or multi-element Yagi antenna, thi
This is a small battery operated Tracking transmitter which broadcasts a repeating radio signal which can be detected by a directional antenna. The transmitter broadcasts an isotropic (radiates in all directions) signal on the FM band. An ordinary FM radio can be used to locate the transmitter, the reception of the signal will improve when the rad
This is an Analogue TV Transmitter. Sound modulation is type FM with a 5. 5MHz carrier and video transmission is PAL. Frequency is adjustable via C5 and tunes 54 to 216Mhz with components shown. This is suitable for countries using TV systems B and G. Please Note: This circuit will be illegal to use in many countries, as such, it is displayed here
fm stereo transmitter ba1404 diagram
Circuit FM transmitter for MP3 and MP4 Player 2n2218 and 741 opamp
Evolution FM transmitter with 2n2218 with audio amplification step using LM741 op amp with audio input for MP3, MP4, mobile, computer and other audio sources, beyond the traditional electret microphone. With great sensitivity to the input signal. Using fewer components and easy assembly makes it ideal for those who want even without much experienc
Circuit Power transmitter of communitarian wireless TV lm1889 audio and video
This small circuit transmitter processes the signs of audio of a sound table or microphone, and the signs of video of a camera, or still the audio signs and video of a DVD, Video-cassette or even it sweats her video plate has an exit of composed video, you can transmit direct of your computer. Playing them in a channel free from the strip of VHF.
Circuit of power fm transmitter transistor 2n2218 audio wireless 1KM
This small transmitter can arrive the more than 1 km in favorable conditions of emission. The modulation can be made so much with a microphone, for an electrets microphone, or other audio source. The 5 turns of enameled thread 22 AWG, with diameter of 1 cm without nucleus. Look at the capacitors that it should be ceramic. The antenna should posses
FM Radio Circuits
RF Receiver Circuits
RF Amplifier Circuits
AM Radio Circuits
FM Transmitter Circuits
Ultrasonic distance finder circuit
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 measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
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 find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
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 circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
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 circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
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, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
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 calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
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 supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
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. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
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