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Novice CW Transmitter
Even though this CW transmitter circuit was published in 1955 in Popular Electronics, it is still legal for today`s Amateur radio operator. Portions of the 40-meter and 80-meter bands are still reserved exclusively for CW operation. As of 2011 in the 40-meter band 7. 025 - 7. 125 MHz, and for 80-meters 3. 525 - 3. 600 MHz are reserved for CW for...
1.8MHz AM transmitter and receiver
Before starting on the receiver side of the` Chatterbox`, we ought to take a final look at the transmitter itself. The Chatterbox transmitter is built separately, because many constructors will want to use it in conjunction with an existing receiver on 1. 8MHz. It`s been assumed that an existing antenna tuner and low-pass filter unit will be used w
valved transmitter for 3.5 MHz
This transmitter project is a highly efficient, rugged and simple, low power c. w. unit delivering more than 10W. As it`s crystal controlled with stabilised h. t. , and a buffer stage between the crystal oscillator and power amplifier stages, it produces an exceptionally clean c. w. performance. Many amateurs will have some, if not all, of the...
Long-range FM radio transmitter circuit
In the circuit shown, the special launch tube T2 and its peripheral parts form a high-frequency oscillator with frequency in the range of 88 ~ 108MHz. The electret microphone picks up the audio signal, then the signal is amplified by T1, then the amplified low frequency signal makes modulation for high-frequency carrier. If the electret...
14W CW TRANSMITTER
Low-power two-stage FET transmitter for 80-meter amateur band uses Pierce crystal oscillator that requires no output resonant ci.rcuit. DC milliammeter can be connected across 150-ohm resistor in gate circuit of second transistor to indicate strength of oscillator output signal, Resonant circuit of RF amplifier Q2 uses toroid L2 (56turns No, 24...
88MHz-108MHz 15W FM transmitter high-frequency amplifier
A ONE TRANSISTOR FM TRANSMITTER
The 2N2222 circuitry is a three-element, phase-shift oscillator circuit, designed to yield a 1,000-Hz sine wave. The 1,000-Hz sine wave is then applied to the TCG-610 varactor diode, 6 pF at 4 V, which changes the tank capacitance, thus varying the rf oscillator frequency at a 1,000-Hz rate. The 1,000-? potentiometer in the collector circuit can...
Simple FM Transmitter
Simple FM transmitter with a single transistor. Mini FM transmitters take place as one of the standard circuit types in an amateur electronics fan`s beginning steps. When done right, they provide very clear wireless sound transmission through an ordinary FM radio over a remarkable distance. I`ve seen lots of designs through the years, some of...
A basic circuit of the transistor UHF radio transmitter with surface acoustic wave resonator (SAW), and the SAW is used as a positive feedback element connected between the transistor VT base and LC network in parallel. Figure (b) shows another basic transistor UHF radio transmitter circuit with the surface acoustic wave resonator
80mW FM transmitter circuit diagram
FM transmitter circuit diagram
This low-power NTSC video and sound transmitter is useful for amateur radio, video handle-talkie, R/C and surveillance pur-poses. A crystal oscillator-multip lier RI` power amplifier. Video modulation is via a three-transistor series modulator. The sound subcarrier is generated with a VC0 circuit and is combined with the video information. The...
The making circuit of crystal oscillator 80mW F.M. transmitter
VHF 0.5 W TV Transmitter
The TV transmitter introduced here can send audio and video signals of satellite television receivers, VCDs and video recorders in open circuit, and receives signals with open antennas. It is suitable for self-made programs of working units, schools, and factories. When folded dipole antenna is used to send signals, the covered distance is...
27MHz NBFM Transmitter
A 27MHz NBFM transmitter circuit schematic with MC2833 and 2 FET transistors MPF6660. Using a Motorola MC2833 one-chip FM transmitter, a few support components and am MPF6660 RF amp, this transmitter delivers up to 3W into a 50 ? antenna. It is capable of operation over about 29 to 32 MHz with the components shown. 27MHz NBFM transmitter circuit...
BH1417 USB FM Transmitter
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 sufficient for reliable reception of its signal within a few tens of meters. The basis of the...
Camera VHF Video Transmitter
This is a simple video transmitter that can transmit as far as 50 meters. This video transmitter can be used with the camera or other video sources. You can view them on VHF channel analog TV. Supply voltage to the video transmitter can use 9V battery. Transistor components that are used for a video transmitter is BC548 or you can use another...
Coilless FM Transmitter
The RF oscillator using the inverter N2 and 10.7Mhz ceramic filter is driving the parallel combination of N4 to N6 through N3.Since these inverters are in parallel the output impedance will be low so that it can directly drive an aerial of 1/4th wavelength. Since the output of N4-N6 is square wave there will be a lot of harmonics in it. The 9th...
FM Transmitter with 2N2218
Here`s simple FM transmitter circuit using medium power 2N2218 transistor. Micropohone is of electret type that connects to two input terminals and the antenna should be a copper wire from 15 to 40 cm. Below is schematic circuit of the fm transmitter..
Micro Power AM Broadcast Transmitter
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 capacitor/resistor combination. A 100pF capacitor is used in place of the crystal for VFO...
Mini FM Transmitter
FM Transmitter is very simple, compact, and has transmission signal with a range of 100-150m, good sensitivity and low current consumption. Transmitter`s schematic consists of a bass amplifier for the first transistor and the proper frequency generator in the second. FM Transmitter divided transitional capacitor that allows you to set up a...
PLL FM Transmitter using LMX1601 ATtiny2313 AT90S2313
Here`s a PLL FM Transmitter using LMX1601, ATtiny2313 or AT90S2313 microcontrollers. The common characteristic of all of the previous low power FM transmitters I`ve built over the decades, is that their operating frequency is determined by an LC resonant circuit. Some of them had excellent stability, some of them didn`t, but I had always wanted...
PLL Stereo FM Transmitter
The circuit shown here is of a good Stereo FM transmitter that can transmit high quality signals up to a range of 70 feet. The circuit is based on BH1417 PLL stereo transmitter IC from Rhom semiconductors. The IC has separate audio processing sections for the left and right channels, pre emphasis circuit for improving signal to noise ratio, crysta
Quality FM transmitter circuit
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 about 200 mW. It works off a 9V battery. The audio-frequency modulation stage is built around transistor BF494 (T1), which is wired as a VHF oscillator and modulates the audio signal present at...
Stereo FM Transmitter Using BA1404
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 circuitry. BA1404 FM transmitter can be operated from 76 to 108MHz and power supply for the circuit can be anything...
Stereo FM Transmitter circuit with BA1404
With this Stereo FM Transmitter with BA1404 you will be able to create a mini stereo FM station and broadcast to your entire home, a simple way to have an audio link wireless with ease. With the FM transmitter BA1404 Hifi Stereo you can stream your music from your iPod MP3, satellite receiver, computer, DVD player, Mobile Phone, MP4 player and...
TV Transmitter circuits
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..
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, action-packed radio program. Due to the power supply via the USB port of a high frequency stability is achieved. Alternatively, the receiver, a battery 5 to 12 volts to operate. FM...
FM Radio Circuits
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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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