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Transmitter Circuits

Transmitters:  #'s       A - C       D - L       M - P       Q - S      
T - Z
 

Last Updated: October 24, 2017 02:55 PM

Circuits Designed by Dave Johnson, P.E. :
Plastic Pipe Finder -  I used this circuit once to track down the location of a plastic pipe, buried underground.  it transmits a weak RF signal, which can be picked up by a portable AM radio from about 6 feet away. . . Circuit by Dave Johnson P.E.-December, 2004

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-368-7747


Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

Magnetic-Radiation Remote-Control -  Short-range 35KHz operation, single-channel units; Simple circuitry, no outer antennas required __ Contact Flavio Dellepiane, fladello @ tin.it

MC145151 PLL FM Transmitter -  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.   __ Designed by Michel P

MC145170 PLL FM Transmitter -  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.__ 

MC145170 PLL FM transmitter -  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

Medium range transmitter -  This is a medium range transmitter circuit diagram.  This is also improved by changing the values of the resistor __ Contact Ashad Mustufa

Medium-Power FM Transmitter -  The range of this FM transmitter is around 100 metres at 9V DC supply. The circuit comprises three stages.  The first stage is a microphone preamplifier built around BC548 transistor.  The next...__ Electronics Projects for You

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 __ Designed by Bill Bowden

Micro Spy with FETs -  Circuit and notes only, no circuit description given.   __ Designed by Tony van Roon  VA3AVR

Micro Spy with TTL -  This circuit is old (70's) but since the 74LS13 is from the regular 74xx series and easy to obtain, I decided to keep the circuit in place until components are no longer available.  Not much to tell here.  Performance is based on the 74LS13, a 'Dual 4-input Positive-Nand Schmitt Trigger'.  This circuit was experimental and so has no real purpose other than tinkering.   __ Designed by Tony van Roon  VA3AVR

Micro Spy with USW -  Circuit and notes only, no circuit description given.   __ Designed by Tony van Roon  VA3AVR

Micro Transmitter Bug -  Presented FM transmitter bug is built using BF414 / BF324 / BF606 transistor.  The 30cm antenna has a range of about 30m in the building, more in the open field.  Power supply 2x AAA batteries have been used with voltage of 2.75 V.  I added resistor 10K in parallel with 1.5pF capacitor so that the system works well when connected to an external source (mp3 player / computer).  On the computer I had to reduce sound to about 35% of capacity, so that I do not have clipping.  I managed to improve transmitter stability with simple shielding.  The coil is 5 turns of enameled copper wire wound on 1 mm Ý = 5 mm.__ 

Micro TV transmistter -  Circuit only __ Designed by Petr Prause, OK1DPX

Micro-Spy with TTL -  This circuit is old (70's) but since the 74LS13 is from the regular 74xx series and easy to obtain, I decided to keep the circuit in place until components are no longer available.  Not much to tell here.  Performance is based on the 74LS13, a 'Dual 4-input Positive-Nand Schmitt Trigger'.  This circuit was experimental and so has no real purpose other than tinkering.   __ Designed by Tony van Roon  VA3AVR

Mini AM transmitter using LM386 & 4 MPF102 FETs for an output stage -  The small Proto PC board (center) holds only the LM386 audio amp, the modulation transformer & the MPF102's.  The oscillator is the separate board to the left.  Because every x-tal synth CB rig I get my hands on, I salvage the crystals, I am using a two-crystal frequency synthesis system to generate the proper BC band frequency. (i'm using 1630Khz, here.  More detail, below.)  __ Designed by N1NKM

Mini FM Broadcast Transmitter -  Build your own simple minI FM transmitter.  This fun project will show you how to build a minI broadcasting transmitter that can transmit an audio signal up to a quarter mile to any FM receiver.  it's easy to build and a good learning experience.  it serves as a hands-on learning tool for students or anybody interested in electronics.  Having a range of up to a quarter mile, it's great for a house security system, baby monitoring device or simply a listening gadget that you can place anywhere! __ 

Mini FM Radio Broadcast Transmitter -  Have you ever wanted to broadcast your own radio station within your neighborhood? This small and simple 87-108MHz FM transmitter is the toy that geeks have always wanted.  This tutorial includes the PCB layout and the schematics.  it has a range of up to 1/4 mile or more.  it's great for room monitoring, baby listening and nature research.__ 

Mini FM Radio Transmitter -  This small FM transmitter with a range of about 50 meters designed for hoby.  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.__ 

Mini FM Transmitter -  9 Volt battery operated simple 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 cascade separately.__ 

Mini FM Transmitter -  Here's how to build your own minI FM transmitter.  it transmits FM waves so you could easily receive the signals on your mobile phone, radios, etc.  As the name and the picture indicates it is very small and is approximately the size of a 9v battery clip.  With this FM transmitter you could start your own minI FM station.  The circuit uses BC547 transistor to amplify the signal and then frequency modulate it.  it uses "frequency modulation" most commonly known as FM, the same principal to transmit audio signals captured by the microphone.__ 

Miniature beeper bumper transmitter for vehicle & asset tracking -  This beeping bug can be attached to anything from a glider to a pot-plant and you can track it with an FM radio.    Why track a pot-plant? Read on to find out__ Designed by Collin Mitchell

Miniature FM (Voice) Transmitter -  Schematic + Notes (Construction) + Parts __ Designed by Tony van Roon  VA3AVR

Miniature FM transmitter -  This miniature transmitter is easy to construct and it's transmissions can be picked up on any standard FM receiver.  it has a range of up to 1/4 of a mile or more.  it is great for room monitoring, baby listening, nature research, etc.  L1 is 8 to 10 turns of 22 gauge hookup wire close wound around a non-conductive 1/4 inch diameter form __ Designed by Andy Wilson

Miniature FM Transmitter -  Schmatic with parts list and notes __ Designed by Tony van Roon  VA3AVR

Miniature FM Transmitter #1 -  This miniature transmitter is easy to construct and it's transmissions can be picked up on any standard FM radio.  it has a range of up to 1/4-mile (Tony van Roon's 400 meters) or more, depending on the line-of-sight, obstructions by large buildings, etc.  it is great for room monitoring, baby listening, nature research,  __ Designed by Tony van Roon  VA3AVR

Miniature FM Transmitter #5 -  4 Transistor Transmitter - Circuit + Parts Lits + Notes __ Designed by Paul K. Sherby

Miniature FM Transmitter #6 -  up to 500 meter range - Circuit + Parts List + Notes __ Designed by Tony van Roon  VA3AVR

Miniature FM Transmitter #7 -  There is no thrill like the thrill you get from operating equipment you have built yourself.  if you have never built a project from a magazine before, let this be your first--you'll see how much satisfaction and fun you can have!  __ Designed by Tony van Roon  VA3AVR

Miniature MW Transmitter -  circuit diagram of simple medium wave transmitter using BF494B.  This simple transmitter have a range of 200 meters__ 

Miniature tracking transmitter -  This little circuit can help you to find your car in a packed parking lot; locate a child who has disappeared in a crowd; or reunite you with a dog that has escaped the confines and safety of your yard.   __ Designed by Tony van Roon  VA3AVR

Morse Adaptor for your VHF/UHF FM rig -  Everyone knows that the best way to practice Morse is to use it on the air.  But how do you send Morse if you donít have a multimode HF or VHF transceiver?Well, you could hold a microphone up to a code practice oscillator, and hold the PTT down while pressing the key, but itís very clumsy, and the transmitted tone is likely to be harsh.  Clearly something better is needed.   __ Designed by Peter Parker

Morse Code Beacon Keyer -  This circuit stores a single morse code message as bits in an EPROM chip, the message is sent to a relay which can key a CW transmitter.  The keyer can output either a one-shot message such as "CQ DX DE CALLSiGN", or a continuous message.  The continuous mode is useful for making beacons for low power (QRP) and slow (QRSS) transmissions __ Designed by G. Forrest Cook

Morse Code Beacon Keyer -  This circuit stores a morse code message as bits in an EPROM chip, the message controls a relay that keys a CW (morse code) transmitter.  An Arduino processor can also be used in place of this circuit, that eliminates the need to build the circuit and program an EPROM. __ Designed by G. Forrest Cook

Morse Code Tutor -  A program (23kb) written in C++.  Morse code uses dot and dash for communication.  Still it is popularly used for communication is short wave bands.  The Archive contains program source code and executable__ 

Morse Keyer -  This is not a sophisticated automatic keyer but it is lot QRP to build and to have fun operating it.   When the paddle is connected to the DOT terminal, C1 starts to charge.  When C1's charge reaches sufficiently high value, it causes the transistor BC157B to conduct and pulls the relay and key the transmitter. __ Designed by K P S Kang

Morse Keyer -  This is not a sophisticated automatic keyer but it is lot QRP to build and to have fun operating it.   When the paddle is connected to the DOT terminal, C1 starts to charge.  When C1's charge reaches sufficiently high value, it causes the transistor BC157B to conduct and pulls the relay and key the transmitter. __ Designed by K P S Kang

MPF102 FM Receiver -  An FM regenerative receiver using a single FET and one audio amplifier IC .   __ Designed by Andy Collison

Multiband CW Transmitter -  A radio frequency oscillator is at the heart of all radio transmitters and receivers.  it generates high frequency oscillations, which are known as carrier waves.  Hereís a continuous wave (CW) transmitter...__ Electronics Projects for You

MW Transmitter -  This transmitter can be used as an inter-room radio telephone.  The communication range of this transmitter is 5 meters only, but the range can be increased to 10-12 meters by installing a 2.5m long antenna horizontally at a height of about 3 meters. __ ` Sigmatone

New & Improved Islander using the NTE474 Transistor -  The islander is a 7-Watt LPFM transmitter using the NTE474 RF transistor.  Together with a half-wave dipole positioned in a vertical stance, the signal leaving the antenna will then radiate evenly in an omni-directional fashion.  With the antenna just at 15 feet above ground level, a signal distance of 3 miles can be achieved.  At an elevation of 50 feet above ground, a signal distance of 10 miles can be achieved.   __ Designed by braincambre500 @ yahoo.com

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Transmitters:  #'s       A - C       D - L       M - P       Q - S       T - Z

 


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