Circuit-Zone.com - Electronic Projects
Posted on Friday, September 3, 2010 • Category: FM Transmitters
5W PLL Stereo FM Transmitter features PLL synthesized drift free operation with high quality BH1415 chip. 5W RF output power is achieved with 2SC1971 6W transistor in the output stage. Front panel digital control comes with LED display and case is made high quality aluminum. The board features EMI filtering on audio and power inputs and comes with Microphone and Audio inputs. Once transmitter is turned on it starts broadcasting with previously selected frequency. Overall this 5W PLL Stereo FM Transmitter provides professional broadcast audio quality and rivals commercial broadcasts.
Posted on Friday, September 3, 2010 • Category: FM Transmitters
This is a unique FM transmitter that provides both a built-in sensitive microphone and an RCA jack for line input. It has two modes of operations, "Microphone" and "Line", which are selectable using a jumper. In the "Microphone" mode, it can be used as a wireless microphone transmitter. In the "Line" mode, it can be easily connected to any audio source to broadcast the audio signal to any FM receiver within its range. 500mW FM / VHF Transmitter Amplifier / Booster can be added for longer transmission range.
Posted on Friday, September 3, 2010 • Category: FM Transmitters
Features PLL tuned transmitter / exciter for rock solid frequency stability over the entire FM band. Displays Transmitted Frequency on backlighted LCD. PCB includes antenna output to which a piece of wire, or VHF amplifier can be connected for greater transmission range. Includes 3.5mm audio jack cable. Plays MP3 from SD and USB memory (SD and USB connectors on board). IR Remote can be used to control the transmitter.
Posted on Friday, September 3, 2010 • Category: FM Transmitters
This is a high quality stereo PLL FM transmitter incorporating a Phase-Locked-Loop (PLL) synthesizer. It is based on the Rohm BA1417 PLL FM Transmitter Integrated Circuit and offers a choice of up to 14 preset transmission frequencies spaced every 200 KHz between: 88.7 – 88.9 MHz (Low Band Mode) and 106.7 – 107.9 MHz (High Band Mode). It has outstanding frequency stability thanks to the PLL crystal controlled design and offers excellent high-fidelity audio performance.
It is ideal for use in your home or office to transmit MP3 songs or internet radio stations from your computer to any standard FM radio. It can also be connected to any other audio source, such as an iPod, a MP3 Player, Walkman, Discman or XM Satelite Radio receiver.
The circuit incorporates a stereo audio input jack as well as a DC adapter jack which makes it quick and easy to setup. Transmission frequency selection is done through a DIP switch.
Posted on Thursday, August 5, 2010 • Category: FM Transmitters
This is an excellent 50mW Hi-Fi PLL FM Stereo Transmitter that features BH1417 chip. ROHM's new Japan has BH1417 is one of the most simple and practical integrated circuits, which combines phase-locked loop circuit, stereo encoder circuit, transmitter circuit, as well as other additions. Pre-emphasis circuit, limiter circuit and low pass filter can significantly improve the sound quality. The total harmonic distortion up 0.3%, stereo separation to 40dB, RF output level is 100dB. BH1417F is an excellent new IC chip, this circuit improves signal to noise ratio (S / N) of pre-emphasis circuit to prevent signal over emphasized limiting circuit, the control input signal frequency low-pass filter circuit (LPF), generate stereo stereo composite signal modulation circuit, FM transmitter phase-locked loop circuit (PLL) component. BH1417F excellent frequency characteristics, it can achieve 40dB of isolation, transmitted sound quality is similar to local FM radio stations.
Posted on Thursday, August 5, 2010 • Category: FM Transmitters
5W PLL Stereo FM Transmitter features PLL synthesized drift free operation with high quality BH1415 chip. 5W RF output power is achieved with 2SC1971 6W transistor in the output stage. Front panel digital control comes with LED display and case is made high quality aluminum. The board features EMI filtering on audio and power inputs and comes with Microphone and Audio inputs. Once transmitter is turned on it starts broadcasting with previously selected frequency. Overall this 5W PLL Stereo FM Transmitter provides professional broadcast audio quality and rivals commercial broadcasts.
Posted on Thursday, July 15, 2010 • Category: FM Transmitters
This Phone FM transmitter connects in series to your telephone line and transmits the telephone conversation over the FM band when you pick up the telephone handset. Transmitted signal can be tuned by any FM receiver. The circuit includes an "On Air" LED indicator and also provides a switch which can be used to turn off the transmitter. A unique feature of the circuit is that no battery is needed to operate the circuit since power is taken from the telephone line. The transmitter uses only a short piece of wire aerial about 4" / 10 cm long to transmit the signal and some of the RF signal is also radiated through the telephone line itself. The circuit might be used to share or record conversations, but is not intended for illegal use.
Posted on Thursday, July 8, 2010 • Category: FM Transmitters
This is a high performance low noise 500mW amplifier / booster for all low power FM transmitters such as BA1404, BH1417, BH1415, 433MHz transmitter modules, etc. The amplifier chip is an integrated circuit containing multiple transistor stages and all other parts conveniently within a single small package. Boosting your FM transmitter has never been easier and the output signal can also directly drive 2n4427 or 2n3886 transistors for 1W or 5W of RF output power.
Posted on Saturday, June 12, 2010 • Category: FM Transmitters
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 1W and 0,2W.
The schematic diagram is divided into three parts: RF part (numbered from 1), PLL (numbered from 30) and audio part (numbered from 50).
Posted on Saturday, June 12, 2010 • Category: FM Transmitters
The TX500 is a simple to build 500mW FM Transmitter. It consists of three blocks; modulator / oscillator, two stage 500mW VHF amplifier and LED based power meter. The TX500 allows to transmit audio signals to FM band at frequencies from 88 MHz to 108 MHz. Due to the very low power consumption of less than 100mA the circuit may be perfectly powered by using 9-12V battery or power supply if you prefer. The circuit has been divided into separate stages so that it is be better for everyone to understand how every part works independently.
Posted on Saturday, June 12, 2010 • Category: FM Transmitters
BH1417 is a latest FM Transmitter IC from RHOM that includes a lot of features in one small package. It comes with pre-emphasis, limiter so that the music can be transmitted at the same audio level, stereo encoder for stereo transmission, low pass filter that blocks any audio signals above 15KHz to prevent any RF interference, PLL circuit that provides rock solid frequency transmission (no more frequency drift), FM oscillator and RF output buffer.
Posted on Saturday, May 22, 2010 • Category: FM Transmitters
This FM transmitter circuit 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 oscillator.
Posted on Thursday, May 6, 2010 • Category: FM Transmitters
This page describes TX ATV Transmitter for 23 cm with output adjustable from 100 to 250mW.
Posted on Friday, April 30, 2010 • Category: FM Transmitters
This new FM transmitter is very simple and doesn't need any RF tuning.
First of all ,we have used an integrated VCO: The POS150 from Mini-circuits.
This excellent RF circuit covers all the FM Band in a voltage range of 4V to 8V.
The Kvco factor is very stable all over the FM band, consequently, we have applied the BF signal directly on the control voltage line coming from the PLL.
Posted on Friday, April 30, 2010 • Category: FM Transmitters
The functioning of all is provided by a microcontroller from MICROCHIP "PIC16F84" which provides support for buttons, LCD 2 lines of 16 characters and the circuit pll "SAA1057.
The VCO is entrusted to the transistor Q8 associate of his two diodes varicaps "BB109, a floor buffer Q7 separates the VHF signal obtained in two ways, on the one hand to Q9 to enslave loop phase and on the other hand to the Q5 and Q6 together which takes care to amplify the signal before attacking Q11, a "BFR96" which plays the role of HF switch via a timer "NE555" which receives information from the push and "SAA1057" ensuring HF cutoff in the event of failure of a locking or unlocking of the pll.
Posted on Friday, April 30, 2010 • Category: FM Transmitters
Filter used for eliminate unwanted harmonic frequency at second and third. Notch filter, Band Pass Filter (BPF), and High Pass Filter (HPF) sometime combined in constructing LPF design.
Schematic below for FM Broadcast Lowpass Filter 88-108 MHz. It has been tested with a good result.
Note : Make the coils at 74 nH and trim them to adjust exact value.
Posted on Thursday, April 29, 2010 • Category: FM Transmitters
In order to simplify the transmitter design, we've used the new pll circuit from Motorola :the MC145170.
This PLL includes the prescaler and a serial standard bus called SPI.
Posted on Wednesday, April 28, 2010 • Category: FM Transmitters
This map, armored also enables automatic MONO / MPX through a low-pass filter, even with a multiplex on its entry by using an ON / ON, panning, the whole spectrum MPX more RDS is sent to the synthesizer, on the other hand when it is in a position MONO, the low-pass filter is activated and share its cutoff frequency at 15 KHz, only modulation G + D is sent to the synthesizer, as 19 KHz. 19 KHz carrier, the signal multiplex and subcarrier 57 KHz is thereby eliminated, which provides ease of use for example in a string of issue relay tuner, if the link between the issuer Departure and receiver re-issue was not of good quality stereo, you sufficient to switch to mono to improve sound quality, you can then connect the RDS encoder at the re-issuer.
Posted on Friday, April 23, 2010 • Category: FM Transmitters
This PLL has been designed with an old Motorola circuit :the MC145151.
The VCO is based on a "Colpitz" oscillator equiped with a Fet Transistor.(J310)
Two varicap Diodes are used in order to reduce the global noise of the VCO.
In addition,these two diodes allow the PLL to keep the lock status through a large range of climatic conditions.
An another J310 is used in order to match the impedance between the oscillator and the fist amplifier stage.
A MSA1105 from Minicircuits increases the RF power level coming from the VCO to +14dBm.
A simple low pass filter rejects the second harmonic to -20 dB.(Worst case)
Finally, a 7 dB attenuator and a second amplifier stage (BFR96S) achieve this radio design.
Posted on Friday, April 23, 2010 • Category: FM Transmitters
This is a universal 1 Watt RF class C amplifier that is ideally suited for low power FM transmitters. Input should be at least 100mW to achieve 1W output. It is recommended to enclose the amplifier in a metal case.
Posted on Thursday, April 22, 2010 • Category: FM Transmitters
This page describes TX ATV Transmitter for 23 cm with output adjustable from 100 to 250mW.
Posted on Saturday, April 10, 2010 • Category: FM Transmitters
This is a PLL controller that works with the VCO/Modulator that I designed. Use these two modules together for a complete baseband-capable exciter unit. This PLL controller features a rock-stable crystal controlled reference, in conjunction with a programmable dividing network which allows the transmitter to be tuned in 100Khz steps from 79.9Mhz to 109.7Mhz by means of digital thumbwheel switches. Oscillator, buffer and driver stages use 2N3866 power RF transistor and output stage used 2N3553 4W RF transistor,
Posted on Friday, February 19, 2010 • Category: FM Transmitters
This MP3 Player FM transmitter can be used to listen to your own music throughout your home. The transmitter circuit use no coils that have to be wound. When this FM transmitter used in the car, there is no need for a separate input to the car stereo to play back the music files from your MP3 player.
This FM transmitter use a chip made by Maxim Integrated Products, the MAX2606. The VCO (Voltage Controlled Oscillator) in this IC uses a Colpitts oscillator circuit. The variable-capacitance (varicap) diode and feedback capacitors for the tuning have also been integrated on this chip, so that you only need an external inductor to fix the central oscillator frequency. The supply voltage to the IC should be between 2.7 and 5.5 V, the current consumption is between 2 and 4 mA.
Posted on Friday, February 19, 2010 • Category: FM Transmitters
This RF power amplifier is based on the transistor 2SC1970 and 2N4427. The output power is about 1.3W and the input driving power is 30-50mW. It will still get your RF signal quit far and I advice you to use a good 50 ohm resistor as dummy load. To tune this amplifier you can either use a power meter/wattmeter, SWR unit or you can do using a RF field meter.
Posted on Friday, February 19, 2010 • Category: FM Transmitters
This design is a 2 stage amplifier that has about 17db of gain, suitable for an input of 50 to 100 MW. Its basically a Veronica 5 watt vco transmitter, without the vco. The transistors are a 2N4427 and a MRF237. Output power is 2.5 to 5 watts, depending on input drive and dc voltage. At 13.7 vdc with 50 MW of drive, the output was 2.5 watts. The maximum dc voltage recommended is about 15-16 volts.
Posted on Saturday, October 31, 2009 • Category: FM Transmitters
The transmitter uses 2 MPSH10 (equiv BF494 or NTE229) transistors in a double-ended free-running voltage controlled oscillator (VCO) operating at half the output frequency on each side and combined at L2, which is tuned to the 2nd harmonic of the VCO and covers the 88-108 MHz range. A standard 9 volt battery is used for power and fits inside the tin. The mono audio input circuit is totally passive with 70us pre-emphasis provided and the audio quality is great.
Posted on Thursday, October 29, 2009 • Category: FM Transmitters
This is a 1 watt amplifier. This design is a 2 stage amplifier that has about 16db of gain, suitable for an input of 5 to 20 MW. The transistors are a 2N4401 and a 2N4427. At 13.7 vdc the most I could get out of the unit was 1/2 watt, you could probably raise the dc voltage to 16 volts and get more output but then a much better heatsink would be required. But for the sake of this project, we'll call it a 1/2 watt amplifier.
Posted on Tuesday, October 27, 2009 • Category: FM Transmitters
The achievement of this 30-watt amplifier has been designed to take place on a heatsink microprocessor PC equipped with its fans, the advantage of this method of cooling has been selected for the fact that it is not very common and expensive. The size of the printed circuit will adapt quite easily to the type of heatsink as you have available, if possible, because in many cases, those of recovery, the fans have already lived and the price of a model remains very affordable.
Posted on Tuesday, October 27, 2009 • Category: FM Transmitters
This Power amplifier is equipped with a bipolar transistor,the famous MRF317 As lots of FM amplifier application ,the power transistor is in a C class bias. All the impedance networks (Input & Output) have been determined by using the software: Mimp.EXE. A 9 elements low pass filter ensures that we meet at least a 60 dB rejection from the carrier.(RF Simulation with RFSIM99) The FM amplifier has a 10 dB gain with a 60 to 65% efficiency. The Input VSWR is around 1.4 and there's no problem to reach the max power in all the FM band.
Posted on Tuesday, October 27, 2009 • Category: FM Transmitters
Be "On Air" with your own radio station! BA1404 based transmitter is an exciting product that will broadcast high quality stereo signal in 88MHz - 108MHz FM band. It can be connected to any type of stereo audio source such as iPod, Computer, Laptop, CD Player, Walkman, Television, Satellite Receiver, Tape Deck or other stereo system to transmit stereo sound with excellent clarity throughout your home, office, yard or camp ground.
Posted on Tuesday, October 27, 2009 • Category: FM Transmitters
That RF Amplifier is for boosting small fm transmitters and bugs. It use two Philips 2N4427 and its power is about 1Watt. At the output you can drive any linear with BGY133 or BLY87 and so on. Its power supply has to give 500mA current at 12 Volts. More voltage can boost the distance but the transistors will be burned much earlier than usual.! In any case do not exceed the 15Volts. The Amp offers 15 dB in the area of 80Mhz to 110 Mhz. L4, L5, and L6 are 5mm diameter air coils, 8 turns, with wire 1mm wire diameter.An easy project, with great results.
Posted on Saturday, August 22, 2009 • Category: FM Transmitters
This watt meter project is very similar to my last wattmeter project. The main reason I made a new project is becasue I needed a unit which could handle higher power than 1W. I found a 50 ohm dummy load which could take 50W of power. Of course I could use attenuates for my 1W meter, but I prefered to build a new unit. The new thing with this project is that it will only display the power in Watt on the LCD display.
Posted on Monday, November 10, 2008 • Category: FM Transmitters
Here is a stereo FM Transmitter based on BH1415F wireless audio link IC. Phase Locked Loop controller use Microchip PIC16F628 and the the PLL frequency programming can be displayed with 8×2 and 16×2 LCD display. The frequency range can adjustable from 88-108 MHz.
Posted on Monday, November 10, 2008 • Category: FM Transmitters
This is FM PLL Stereo based BH1415F IC from Rohm, it's has built in PLL and Stereo Encoder. You can download the schematic, pcb layout and Hex code. The transmitter menu display with LCD, and this have step 100Khz, 200Khz,.....1000Khz and have Mode menu (stereo/mono). In Action, LCD Display can solder directly on the bottom.
Posted on Tuesday, May 6, 2008 • Category: FM Transmitters
This is a high quality PLL Stereo FM Transmitter with build-in VHF amplifier for longer transmission range. It is based on BH1417 chip that offers high quality crystal clear stereo transmission. Eight available frequencies are controlled by grounding S1, S2 and S3 pins on header connector. Includes, high quality ROHM BH1417 transmitter chip, on-board amplifier increases transmission range, uses 7.6MHz crystal for rock-solid PLL FM transmission, crystal based Stereo Encoder and 3.5 standard audio input jack.
Posted on Thursday, April 24, 2008 • Category: FM Transmitters
Many people prefer to listen to their own music (or voice) on radio.
This project explain how you can build and connect a powerful 1W amplifier to your FM transmitters.
A perfect solution for those wishing to listen to their favorite tunes in the car, house, garden,
school, campus, party, you name it....
Why not share your music with every one else in your city!
Posted on Thursday, April 24, 2008 • Category: FM Transmitters
BH1415F FM Stereo PLL Transmitter
Transmitter power amplifier, the output signal from BH1415F by 2 SC9018, 2SC3355, 2SC2053 amplified signal can reach more than 500 mW, adjusting well to achieve greater power. Measured by the pull rod antenna used to be launched in the open 800 meters above. Uses external antenna will be launched even further. attention in 2053 need to be installed and tested at the load connected to leave, or else very easily burn 2053, 50 European amateur production of 2 W can be used instead of resistance. installed and tested at three levels circuit can be installed and tested.
Posted on Wednesday, April 23, 2008 • Category: FM Transmitters
A simple FM transmitter links your home-entertainment system to a portable radio that can be carried around the house and into the back yard. For example, you can play music on the CD changer in your living room, and listen to it on a portable radio by the back-yard barbeque.
IC1 is a voltage-controlled oscillator with integrated varactor. Its nominal frequency of oscillation is set by inductor L1, and a 390nH value places that frequency at 100MHz. Potentiometer R1 then lets you select a channel by tuning over the FM band of 88MHz to 108MHz. Output power is about -21dBm into 50 (most countries accept emissions below 10dBm in the FM band).
The home system's left and right audio signals are summed by R3 and R4, and attenuated by the (optional) potentiometer R2. R2's wiper signal serves as a volume control by modulating the RF frequency. Signals above 60mV introduce distortion, so the pot attenuates down from that level.
In the absence of a standard FM radio antenna, 75cm (30 inches) of wire will suffice as a transmitting antenna. For best reception, it should be mounted parallel with the receiving antenna. The IC operates on a single supply voltage in the range 3V to 5V, but you should regulate the applied voltage to minimize frequency drift and noise.
Posted on Sunday, April 20, 2008 • Category: FM Transmitters
Now you can use your MP3 Player to listen your favorite tunes through any FM stereo receiver. Wireless FM transmitter wirelessly connects portable music players to your car or home stereo quickly and easily. Just plug the FM Transmitter into the headphone jack of your MP3 or any audio source including iPOD, PDA, CD Player, Cassette player or connect it to your PC or laptop computer. Tune your card stereo or receiver to the clearest FM frequency, and enjoy your digital music with full sound and convenience.
Features:
- PLL tuned transmitter / exciter for rock solid frequency stability over the entire FM band
- Displays Transmitted Frequency on blue backlighted LCD
- 100KHz frequency increments
- Includes three frequency memory buttons
- PCB includes antenna output to which a piece of wire, or standard VHF amplifier can be connected for greater transmission range
- Uses PLL synthesizer chip up to 1.4GHz
- Includes 3.5mm audio jack cable
- Small size
Posted on Tuesday, April 15, 2008 • Category: FM Transmitters
This is a high quality PLL Stereo FM Transmitter with build-in VHF amplifier for long transmission range. It is based on BH1417 chip that offers high quality crystal clear stereo transmission. Eight available frequencies are controlled by grounding 3 pins on header connector. This transmitter comes assembled and is ready to use.
Features:
- Two on-board transistors increase transmission range
- Uses 7.6MHz crystal for rock-solid PLL FM transmission
- Crystal based stereo encoder
- Very small size
Posted on Monday, April 14, 2008 • Category: FM Transmitters
Here is the latest and greatly improved TX200 VFO/VCO FM transmitter. The most versatile transmitter to date that can be turned into high fidelity stereo PLL based 200mW FM transmitter. It is a perfect circuit for transmitting your music around the house and yard. TX200 uses only two coils; one in the oscillator and the other one in the 200mW VHF amplifier so it should be fairly easy for anyone to build. It also includes built-in pre-emphasis and C5 for enhanced sound quality. While assembling the transmitter care must be taken to make sure that C1 is directly connected to L1 and C9 to L2. These caps eliminate the distortions form the DC supply and improve the sound quality greatly. 9V voltage supply is also very important because it provides the exact amount of current to Q1 to produce loud and clear sound quality.
Posted on Thursday, April 10, 2008 • Category: FM Transmitters
This project will explain the basic function of a class-C transmitter. I will explain how to dimension a transmitter and the purpose of the different components. I will also explain how you can build a 1.5W PA transmitter. The project will include PCB, components and instructions how to make coils, assembly and testing.
Posted on Thursday, April 10, 2008 • Category: FM Transmitters
This is the latest BH1417 FM Transmitter design from RHOM that includes a lot of features in one small package. It comes with pre-emphasis, limiter so that the music can be transmitted at the same audio level, stereo encoder for stereo transmission, low pass filter that blocks any audio signals above 15KHz to prevent any RF interference, PLL circuit that provides rock solid frequency transmission (no more frequency drift), FM oscillator and RF output buffer.
There are 14 possible transmission frequencies with 200KHz increments that users can select with a 4-DIP switch. Lower band frequencies start from 88.7 up to 89.9 MHz, and upper band frequencies start from 107.7 up to 108.9 MHz.
Posted on Tuesday, April 8, 2008 • Category: FM Transmitters
Very stable FM transmitter based on TSA5511 synthesizer. Frequency is performed with three buttons through PIC16F84 microcontroller. Frequency is displayed on 16×1 LCD.
Posted on Wednesday, April 2, 2008 • Category: FM Transmitters
Be "On Air" with your own radio station! BA1404 based transmitter is an exciting product that will broadcast a high quality stereo signal in the 88 – 108MHz FM band. It can be connected to any type of stereo audio source such as personal computer, CD player, Walkman, television, tape deck or stereo system to transmit stereo sound with excellent clarity throughout your home, office, yard or camp ground.
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