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DIY remote control based on PIC - Control up to 8 devices by this easy constructable remote control. it can work as a radio or infrared remote control, depending on the components. Each device output can be configured to be momentary (turned on while you press the button) or latched. Latched outputs can be toggled on/off by one button per channel, or turned on and off by two buttons per channel __ Designed by Peter Jakab
Dog Warden - a simple radio transmitter and reciever to signal when a dog has strayed too far __ Contact P. Townshend - EduTek Ltd
Doodle Labs DL435-30 420-450 MHz OFDM Transceiver Experiments - Experimenting with high-speed data in the 440 MHz ham band. __ Amateur Radio circuits from Green Bay Professional Packet Radio
DSP-10 transceiver project - DSP-based 2m transceiver controlled by a Personal Computer (made in June 2001) __ Designed by Bjarke Korsgaard
DTMF Radio Remote Control - Here is a circuit of a remote control unit which makes use of the radio frequency signals to control various electrical appliances. This remote control unit has 4 channels which can be easily extended to 12. This circuit differs from similar circuits in view of its simplicity and a totally different concept of generating the control signals __ Designed by Radioland.net
DVB compliant IP gateway - This project is now well under way and works fine. The modulator which will do DVB-S (QPSK with viterbI and RS) is still being developed. The gateway uses a Linux PC with a SLiP connection as a source and will modify the data to encapsulate it using the DVB mechanism so it can be received with commercial satellite receiver cards. PMT, PAT and SDT tables are transmitted as well so the data stream can be scanned by the receiver. __ Designed by Edward John Cardew
Earwig -FM Transmitter - This is an easy to build FM transmitter that fits into a matchbox. it transmits to any standard FM radio and can be used around the home as a baby minder or outdoors for up to 300 metres. its sensitivity and clarity are very impressive -even the ticking of a clock can be picked up 3 metres away. Almost everyone has the ambition to use the airwaves. Whether it be for remote control or transmitting halfway around the world, we all love to broadcast __ Designed by Collin Mitchell
Easy 2 Meter Transmitter - This project is a simple transmitter using only one crystal and will cover 145.00 to 146.00 MHz. The crystal is a 44.9333 MHz crystal for 145.500 receive, as used in the Trio (Kenwood) 2200, PYE, Motorola, Tait equipment, to name but four. The frequency of the crystal is not critical as almost any other Xtal for the 2-meter band will function __ Designed by Harry Lythall-SM0VPO
Easy FM transmitter 0,4 W - Schematic + Parts List + PCB __ Jan Kolar
Easy Ten - A very simple 80 meter CW one transistor QRP transmitter made from a common npn transistor, two resistors, two capacitors, a 3.5 - 4 mhz crystal and a 9v battery. I call this transmitter "The Easy Ten" because it can be easily heard from a distance of over ten miles. This article includes some good basic philosophy on antennas. __ Designed by Nyle Steiner K7NS
Filter simplifies software Defined radio - 12/03/07 EDN Design ideas: A LTC1992 filter replaces four op amps in the signal chain of a software-defined radio Design by John Wendler and Ray Tremblay, Tyco Electronics, M/A-Com Wireless Systems, Lowell, MA
Five by Twenty SSB QRP Transceiver - A 5 tubes SSB QRP Transceiver for 20m Ham band - The complete schematic shown here includes the supply section, but omits the low-voltage part needed to drive the relays coils. I'veused a voltage doubler from the 6.3VAC of the tube heaters because I chose 12V relays. __ Designed by Andrea IW9HJV and Johnny IW9ARO
FM Band Monaural Transmitter - A high quality monaura FM transmitter is quite useful in a variety of applications. The audio from a TV or entertainment system may be transmitted for remote or portable listening and for wireless earphone listening. The audio from an AM receiver placed near a window can be retransmitted within a metal building where AM reception is not possible. Two transmitters will convert two portable __ Contact: Charles Wenzel of Wenzel Associates, Inc.
FM Band Preamplifier - Here is a high performance RF amplifier for the FM band which can be successfully built without any special test equipment. The grounded-gate configuration is inherently stable without any neutralization if reasonably good layout techniques are employed. The output transformer is designed to resonate with the FET's drain capacitance at about 92 MHz giving the amplifier the highest gain at the low end of the band where the weaker stations operate. No tuning capacitor is needed as long as the transformer is built precisely as described __ Contact: Charles Wenzel of Wenzel Associates, Inc.
FM Beacon 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 draws about30 mA from a 6-9 volt battery and can be received to about100 yards. __ Designed by Bill Bowden
Fm Booster - Here is a low-cost circuit of an FM booster that can be used to listen to programmes from distant FM stations clearly. The circuit comprises a common-emitter tuned RF preamplifier wired...__ Electronics Projects for You
FM Broadcast Audio Transmitter - A nice AC mains powered transmitter with pre-emphasis, audio level control, and tuning control. Notice: Before operating a radio transmitter, find out what kind of transmitter operation, if any, is permitted in your locality. Radio transmitter operation is a serious legal matter. in the United States, operation of unlicensed intentional radiators is covered by Part 15 of Title 47 of the Code of Federal Regulations. This design can be readily adapted to different frequencies and different power levels. if you choose to build and operate the transmitter described here, you do so at your own risk. i'm only publishing this as an example of what can be done. __ Designed by Dick Cappels
FM Bug - This FM bug transmitter circuit will let you spy on people. The transmitter can be placed in the desired room and the conversation heard from a place far away just using...__ Electronics Projects for You
FM bug 420-480 MHz - How about getting that old Nokia phone out of your drawer and turning it into something freakishly cool? I will not lie to you, you will need a few tools and skills such as soldering/desoldering and making PCBs. Here you can download Sprint-Layout__
FM Bug-transmitter - The circuit consists of two separate stages. The first is an audio pre-amplifier and the second is a 90MHz oscillator. The first stage is very simple to explain. it is a self-biasing common-emitter amplifier capable of amplifying minute signals picked up by the electret microphone __ Contact kit is designed and manufactured TALKING ELECTRONICS
FM Microphone - Here is the super NEW miracle improved "Frequency Modulation Wireless Microphone" (BUG) with added easablilty, readability and copyability. This was necessitated after the number of E-Mail questions posed by people who were confused by the layout of the project (s). Before proceeding with the interesting bits, please note __ Designed by Harry Lythall-SM0VPO
FM Microphone - A micro-transmitter is so small and sensitive, it have only 8 easy-to-get parts and can be assembled in one hour. __ Designed by Jose Pino
FM Radio - Last summer vacation, I had an opportunity to be in dad's hobby workshop and decided to have a look at my pending projects. (I am no longer a science student but now in School of Fashion Technology for my BS Degree) I realized that I had a lot of parts in boxes that I ordered and must be utilized! ! I decided to complete this FM Radio project as all that was to be done was to design a board. __ Designed by Nina Gajjar
FM Radio Microphone with Internal Loop Antenna (Area 50) - This article began as a design guide for hyper cranial erogenic field generators, however, your primitive earth brains are completely unable to respond to erogenic fields in the 100MHz region. I personally had a brain upgrade (for purely medical purposes of course) so I am able to respond __ Contact: Charles Wenzel of Wenzel Associates, Inc.
FM Radio Transmitter - 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 one and a half turns from the supply end. Audio sensitivity is very good when used with an ECM type microphone insert. __ Designed by David Sayles
FM Radio Transmitters with Opamp - An low power FM Transmitter using an op-amp as the audio preamp and a single transistor as the RF amplifier. __ Designed by Kamran Ahmed
FM Receiver using MPF102 - An FM regenerative receiver using a single FET and one audio amplifier IC . __ Designed by Andy Collison
FM Stereo Modulator - This circuitry is used for generating a high quality FM stereo multiplex signal that is suitable for driving mono FM transmitters. The Rev E2 FM stereo multiplex generator is the most recent design in a series of circuits that have appeared on this site. This version features improvements to the audio mixer stage, better gain adjustments in the audio filter stage and a rework of the multiplexer stage. When it is adjusted properly, the Rev E2 design produces an FM stereo signal with excellent fidelity. __ Designed by Forrest Cook
FM Synthesizer N°1 - 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. __ Designed by Michel P
FM Synthesizer N°2 - 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, (08/08/08) __ Designed by Michel P
FM Telephone Bug - Receive telephone conversations on any FM radio with this neat little device. __ Designed by Tony van Roon VA3AVR
FM Telephone line Bug Transmitter - Here is a simple transmitter that when connected to a phone line, will transmit anything on that line (execpt the dial tone) to any FM radio. The frequency can be tuned from 88 to about 94Mhz and the range is about 200 feet. it is extremely easy to build and is therefore a good, useful beginner project. __ Designed by Aaron Cake
FM Telephone Transmitter - Receive telephone conversations on any FM radio with this neat little device. __ Designed by Tony van Roon VA3AVR |
