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FM Transmitter Circuits
FM Transmitter Circuits
PLL 1 Watt FM transmitter
This small FM transmitter includes a limiter, a microphone amplifier and a PLL digital tuning. All the parts are placed on one circuit board. The RF power is switchable between 1 W (HI) and 0,2 W (LO). Technical specifications: Supply voltage: 12 V from accumulator or regulated power supply. Supply current (HI/LO): 270/170 mA. RF power HI: 1 W....
FM bug circuit
This is just one of the many bugging devices available on the eaves-dropping market. The range includes pen and pencil holders, trophies, framed pictures and office furniture with false bottom drawers. These products are readily sold to fledgling companies, eager to nestle into big brother's market. And for a while these bugging devices...
Reliable FM transmitter
The power output of most of these circuits are very low because no power amplifier stages were 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,...
Colpitts oscillator FM transmitter
Its frequency depends on the capacitance of the vary cap diode. The center frequency is changed by varying the biasing voltage of the vary cap through the 47K pot. You can use a 75cm telescopic antenna or simply a length of hook-up wire. Mine worked fine with a 6cm hook-up wire and gave a range of 100m with a good FM receiver.
Coilless FM transmitter circuit
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...
Phone line FM transmitter
Here is a simple yet very useful circuit which can be used to eavesdrop on a telephone conversation. The circuit can also be used as a wireless telephone amplifier. One important feature of this circuit is that the circuit derives its power directly from the active telephone lines, and thus avoids use of any external battery or other power...
Pll Fm Radio Transmitter Circuit Schematic
Crystal Controlled FM Transmitter
The FM transmitter is relatively simple to build and with only one adjustment it is ideal for the absolute beginner. But before I continue, let me just make one thing clear. With Wide-Band deviation, the VCO is never locked in phase, only in frequency. It uses a Varicap diode to modulate an oscillator, then lock the oscillator in a Phase Locked Lo
3volt FM TRANSMITTER PROJECT
This project provides the schematic and the parts list needed to construct a 3V FM Transmitter. This FM transmitter is about the simplest and most basic transmitter to build and have a useful transmitting range. It is surprisingly powerful despite its small component count and 3V operating voltage. It will easily penetrate over three floors of an
FM Transmitter circuit using 2N2222
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 capacity C4, R3 and R4 resistor performs the function of the output mix theaudio to stereo pl
Low Power FM Transmitter Schematic
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 have to disable the FM receivers mute circuit to hear this). Because the trimmer cap is ve
Very simple fm transmitter
1W PLL FM transmitter schematic
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 be able to use the PLL. All info about the PLL is available at Plessey`s web page.
Schematic for the Micro FM transmitter
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 this up more or less as I built the circuit: in my circuit C1 is a small air variable cap tha
SMD FM Transmitter
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 they have some problems. First, you need an audio amplifier to get enough modulation. Second,
fm transmitters circuits
2 Transistor Mini FM Transmitter
This is a mini FM transmitter built and powered using 2 transistors, designed by Tony van Roon. This small transmitter is simple to build and its transmissions could be picked up on any common FM radio. It possesses a range of approximately 1/4-mile (400 meters) or even more, depending on the line-of-sight, obstructions by big buildings, and so on
4 Stage FM transmitter circuit diagram
4 Stage FM transmitter circuit diagram. It uses four radio frequency stages: a VHF oscillator built around transistor BF494 (T1), a preamplifier built around transistor BF200 (T2), a driver built around transistor 2N2219 (T3) and a power amplifier built around transistor 2N3866 (T4). A condenser microphone is connected at the input of the oscillat
9V FM Radio Transmitter
Here the simple and low cost FM transmitter circuit. The frequency range of this FM transmitter should be about 89MHz 109MHz. Output power is about 9mW at 9V. R1, R6_12K R2, R4_100K R3_22K R5_1K R7_100R Q1_BC338 Q2_BC548B Microphone JinIn ECM-60P B1 C1_10uF/25V C2_22n C3_10n C4_3n3 C5_2p7 C6_22p C7_100uF/16V tuning capacitor_0-30pF This is a low
Mini FM Transmitter
This is a mini FM transmitter built and powered using 2 transistors, designed by Tony van Roon. This small transmitter is simple to build and its transmissions could be picked up on any common FM radio. It possesses a range of approximately 1/4-mile (400 meters) or even more, depending on the line-of-sight, obstructions by big. This is probably t
Good Quality 500M FM Transmitter
Good Quality FM transmitter circuit for your amplifier, gives you a pretty good signal strength up to range of 500 metres having a power output of about 200 mW
sensitive FM Transmitter
Simple and easy build of FM transmitter circuit. The circuit only require 2 transistors. Circuit Notes: Typically the default for the capacitors model is ceramic, preferably the npo 1% type or equivalent. However, generally almost nothing critical right here. Work with any capacitor you`ve laying arround, but DO NOT use any electrolytic or tantal
Mini FM Radio Transmitter Circuit
15V Simple FM Transmitter
This simple FM (frequency modulation) transmitter is powered only by a 1. 5V battery and uses only one frequency of this transmitter transistor. The is controlled by the LC resonant circuit and operates from 80 to 110 MHz The inductor L1 is 8 turns of wire wound magnetic No. 22 with diameter of 4 to 5 cm or the diameter of a pencil. The antenna...
1-Transistor FM Transmitter
1-Transistor FM Transmitter. R1 27k R2 56k R3 12k R4 100 C1 1u C2, C3 470p C4 6 to 10p C5 1-30p trimmer L1 etched on PCB or a.
3-3.5 Watt FM Transmitter
3-3.5 Watt FM Transmitter. This is the schematic for an FM transmitter with 3 to 3.5 W output power that can be used between 90 and 110 MHz. Although the stability isn`t so bad, a.
4W FM Transmitter
4W FM Transmitter. TECHNICAL CHARACTERISTICS: Stabilised tendency of catering: Vcc=12~16V Frequency of emission: 88~108MHz Consumption: 100~400mA Materially: The.
AM FM Simultaneous Transmitter Using Digital IC
FM Beacon Broadcast Transmitter (88-108 MHz)
FM Beacon Broadcast Transmitter (88-108 MHz). This circuit will transmit a continuous audio tone on the FM broadcast band (88-108 MHz) which could used for remote control or security purposes. Circuit.
Low Power FM Transmitter
I have had a few inquiries about a low power FM transmitter, and this article should satisfy those who might want to build one. It is designed to use an input from another sound source (such as a guitar or microphone), and transmits on the commercial FM band it is actually quite powerful, so make sure that you select an unused position on the
Sensitive FM Transmitter
Sensitive FM Transmitter. Additional Notes The default for the capacitors type is ceramic, preferably the npo 1% type or equivalent. But basically nothing critical here. Use any.
Transmitter FM 45W with valve
Transmitter FM 45W with valve. TECHNICAL CHARACTERISTICS: Tendency of catering: 220V AC Frequency of emission at FM: 88~108MHz Force of expense: max 45W (without the.
FM Radio Circuits
RF Transmitter Circuits
RF Receiver Circuits
RF Amplifier Circuits
AM Radio 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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