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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. :

175Khz Inductive Pulse Transmitter -  This circuit is discussed in more detail in the Experimenters Journal.  The transmitter’s six-inch diameter coil launches powerful magnetic 175KHz ring pulses that can be detected by the circuit below . . . Hobby Circuit designed by David Johnson P.E.-June, 2000

3Khz Filter + Audio Amplifier -  This circuit is the audio amp section for a complete optical transmitter.  The circuit amplifies and filters the voice audio signals from an electret microphone.  The circuit is described in more detail in . . . Hobby Circuit designed by David A. Johnson P.E.-June, 2000

40khz TV-VCR Light Source Repeater -  This circuit is designed to be placed directly in front of a standard TV or VCR remote.  The exiting light pulses produced by the circuit match the pulses from the remote but are about 10 times more powerful.  Using the device, the remote can operate a TV or VCR over three times the normal distance. . . Circuit by David A. Johnson P.E.-June, 2000

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:

5 tubes SSB QRP Transceiver for 20m Ham band -  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

5 Watt 80 Meter QRP CW Transceiver -  A great deal of interest has been generated by my previous design articles, so I decided to go to work on a full blown transceiver design.  After several months of work, the ROSE-80 transceiver was born.  This transceiver is similar to other designs but contains some unique differences.  This design boasts the following features __ Designed by Radio Amateur Society of Norwich

5 Watt FM Amplifier -  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.__ 

5 Watt HF CW transmitter -  This is a very simple 5 watt CW TX based upon a TTL logic chip.  There is just one "tricky" component and this is Cx.  This component should have an impedance of about 10 - 50 ohms at the frequency of interest.  if you wish to reduce the transmitter power, increase the value of Cx.  it is Cx which causes the square wave from the output transistor to approximate a sine waveform.  The value of Cx is the price of simplicity in this TX __ Designed by Harry Lythall-SM0VPO

5 Watts FM RF Amplifier -  This fm rf amplifier uses 2SC1971 transistor to provide 5 watts of output.  Output matching is adjusted via the two 40pF trimmer capacitors likewise also to the input.  Note that the emitter of this transistor is directly grounded on the heat sink and should have a good thermal transfer.  Driving power of 100 to 200mW can be applied in order to provide 5watts of output__ 

50 Hz controlled 10 MHz refferance with PIC16 & LCD display -  My Radio amateur callsign is OZ2CPU.  I like to use Atmel AVR Atmega PIC 16 PIC 16F876 PIC 16F84.  Most electronics easy made for the novice and something is for the more experienced.   __ Designed by Thomas Scherrer OZ2CPU

500mW AM transmitter for the 20 meter band (14MHz) -  in this project, you will make a simple low-power broadcast-type circuit, using a crystal oscillator integrated circuit and an a collector modulated AM oscillator. You can connect the circuit to the an electrec microphone (pointed out in gray on the diagram) or amplified dynamic microphone (no amplified microphone has a to low output voltage to work. Approx.100mv is needed). You could also add a LF preamp stage of one transistor to allow connecting a dynamic microphone directly. __ Designed by Guy Roels ON6MU

500mW Broadcast FM Transmitter -  This little broadcast FM transmitter has 500mW of RF output power and runs of 12-15V battery or power supply.  DC whose signal modulated by FM using four transistors.  Transmitter includes four transmitter stages and draws around 100-150mA of current.  Using the values of the circuit components, the frequency will be around 100 MHz but can be changed via coil.  Through the 5 pF capacitor and 10K ohm resistor, the modulation of audio signal is supplied to the tank circuit.  The amount of modulation is being managed by the 1N4002, a general purpose rectifier diode.  FM Transmitter's output stage is functioning as a class D amplifier where the output transistors act as a switch.__ 

500mW FM / VHF Transmitter Amplifier / Booster -  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 2n3866 transistors for 1W or 5W of RF output power.__ 

500mW HF Linear Amplifier -  his project was a particular surprise for me in that the BC547 (equiv 2N2222) can be used to build a 500mW linear amplifer covering the entire HF band with excelent spectral purity and no neutralising at all.  Ugly-bug construction was used but I dare say that the good results are partly to do with the method of construction. __ Designed by Harry Lythall-SM0VPO

50MHz power Amplifier -  Schematic only, no circuit description __ Designed by JH0WJF

50mW BH1417 Stereo PLL FM Transmitter -  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.__ 

5W PLL FM Transmitter -  Easy to build high-quality PLL FM transmitter with typical output power of 5 W and no-tune design.  The transmitter includes RDS/SCA input and Audio/MPX input with optional pre-emphasis.  it can be used with or without stereo encoder.  Tuning over the FM band is provided by two buttons that control dual-speed PLL.  The transmitter can work also without the LCD display.  Some experience with building devices of this kind are highly recommended.__ 

5W PLL Stereo Transmitter with LCD -  Here's PLL FM transmitter circuit from china.  This circuit uses the familiar 2SC1971 for final power amplifier stage.   __ Contact sky @ cantonmade.com and balalove2008 @ hotmail.com

5W QRP with KT907 -  Schematic only, no circuit description __ Designed by © 2001 - YO5OFH, Csaba Gajdos

6 Transistor Super Regen Receiver -  Solid State Superregenerative Receiver.    This is the only solid state super regen design with more than 20uV sensitivity on FM that I know of.   __ Contact blehack @ yahoo dot com

6 Watt FM Transmitter Amplifier -  After building FM transmitter I decided to build a 6W RF Transmitter amplifier for the FM band to get more power and we chose to copy a 6 Watt design built around 2SC1971 RF power transistor.  We were not satisfied with finished result and decided to replace the fixed capacitors around the pcb inductors with variable capacitors, this is much better and possible to tune to your transmitter frequency.__ 

6 way broadband RF distribution 20dB coupler -  My Radio amateur callsign is OZ2CPU.  I like to use Atmel AVR Atmega PIC 16 PIC 16F876 PIC 16F84.  Most electronics easy made for the novice and something is for the more experienced.   __ Designed by Thomas Scherrer OZ2CPU

60W Linear Amplifier -  The 60 Watt linear amplifier is simple all solid state circuit using power MOSFET iRF840.  The iRF series of power transistors are available in various voltage and power ratings.  A single iRF840 can handle maximum power output of 125 watts.  Since these transistors are used in inverters and smps they are easily available for around Rs: 20/- __ Designed by Mohamed Agha

6W FM Transmitter 88-108 MHz -  Presented FM transmitter is built around low power PLL transmitter and amplifier that boosts its signal all the way up to 6 Watts.  The signal is amplified by three RF stages of amplification.  in the first and second stages of the transmitter one of the best driver transistors were used 2SC2053.  You can use the other transistors but only up to 500mW of power.  in the third stage 2SC1971 RF transistor was used to achieve 6W of power.  For making any RF transmitter circuit at least two meters are necessary, one is frequency counter and the other is RF field strength meter for which the schematic is provided.__ 

7 Watt FM Transmitter -  This 7 Watt FM Transmitter was originally a 200mW unit, without the universal power stage added.  Together with the power amp 2SC1971 / MRF237 / NTE342 it then became a 7W unit.  I used this transmitter with a half-wave open-end dipole in a vertical position 50 feet above ground.  Together with about 70 feet of coax, this transmitter delivered great audio at a distance of 10 miles overall distance was 17 miles, but the audio signal was weak.  I had no equipment, other than a watt meter to measure it's power and a digital FM tuner with a 5-LED Signal Strength Bargraph display to use as capturing the main oscillating frequency, which was right at 87.5 MHz.  This circuit worked well for me, as I had experimented with it for nearly a year.  Of course, one would be better off with more equipment than I have had to capture the main oscillating frequency.  That was, by far, one of the hardest things to capture.  it was thru trial and error, with the FM tuner, in finally finding out how to grab the right frequency.  When I finally did get used to find out where my 'main' frequency was, the unit performed extremely well.  Like I had said above, right at 10 miles, the unit was at its best giving clear audible audio into the speakers of my car.  With the transmitting antenna at 50 feet above ground, I decided to see how well I could receive the transmitter signal from an overpass than is exactly 15 miles from the transmitter.  When I got to the top of the overpass in my car, the audio signal came in as 'clear as a bell'.  I now understand what is meant when one says FM signal travels best in a line of sight.  Well, being on that overpass, if I had a strong telescope with me, I am sure I could see the 50 foot antenna in my oak tree.  So with the overpass being right around 50 feet in height also, the transmitter surpassed my judgement call on its signal.  I surrender this circuit to anyone who likes to experiment in things like this.  Enjoy! __ 

76-110MHz FM Radio Transmitter -  Here is a simple 76-110MHz FM transmitter that can transmit your voice or audio over an ordinary FM radio within the FM broadcast band.  it can transmit both voice using microphone and music from any music player.  Frequency is changed by adjusting 5.5 turn inductor coil.  Transmitter is powered by 9V battery or 3V-9V power adapter.  Transmission range is 100 meters but can be increased with better antenna or RF amplifier.__ 

76MHz-110MHz FM Transmitter with Booster -  Three stage FM transmitter with an on board signal booster for increased transmitting range.  it broadcasts audio on 76MHz - 110MHz FM frequency via included on board microphone or from MP3 player, Phone, iPod, Computer, Laptop, CD Player, TV, Satellite Receiver via on board 3.5mm connector.  it transmit sound with excellent clarity throughout your home, office, yard, camp ground, etc.  Transmitter is supplied by 3-12V DC voltage and uses one 2SC9014 and two 2SC9018 low noise RF transistors.__ 

7mhz CW/AM QRP Transmitter -  The circuit of a 7MHz C W / A M QRP transmitter described here can be used to transmit either CW or audio frequency modulated signal over a 7MHz carrier. The carrier...__ Electronics Projects for You

7MHz QRP Transmitter -  This was one of my very first transceiver developments.  This page was also one of the very first circuit descriptions that I put on the internet quite some years agon.  Today I would not build a transceiver like I did then, but it was working, so I have kept this page for historical (and sentimental) reasons.  if you are a beginner in building you own transceivers you might be able to steal a few of my ideas.  Please let me know if you do a full copy of the design, I would be interested in you practical experiences when operation on the air.   __ Designed by Herbert Dingfelder

8 Channel ADC for Radio-SkyPipe -  This is a Radio Astronomy Project __ Designed by Radio-Sky Publishing

8 Channel RF Remote Control -  This is an 8 Channel RF Remote Transmitter and Receiver that will allow to remotely control various electronic projects.  RF Remote Control provides 2 latched and 6 momentary outputs that could be used to control your favorite devices such as amplifier, robotic devices, RC cars, computer, home appliances, lamps and many other cool gadgets.  __ 

80 Meter DSB Transmitter -  amateur radio construction projects.   __ Designed by Peter Parker

80 Meter, 5 Watt CW Transceiver -  A great deal of interest has been generated by my previous design articles, so I decided to go to work on a full blown transceiver design.  After several months of work, the ROSE-80 transceiver was born.  This transceiver is similar to other designs but contains some unique differences.  This design boasts the following features __ Designed by Radio Amateur Society of Norwich

80 Metre CW beacon / transmitter -  The local Homebrew Group has been talking about Peter Parker VK3YE's Carnegie Communicator project in Lo-Key.  The general design of the circuit (based on the old "Oner" CW transceiver) lead in the usual round-about way to build this CW beacon.  OK, so how does a top-band AM transceiver lead to a Morse beacon? Well, inspiration is a complex thing, and with the PSK beacon stuck in phase jitter hell, a CW beacon sounded like a good project to initially test the waters with.   __ Designed by © 2000 - 2009 Alan Yates

80 Metre DSB Transmitter -  This circuit is probably the simplest practical 'bare-bones' voice transmitter for the 3.5 MHz amateur band.  Unlike other simple transmitters, this one transmits DSB rather than AM.  This makes it more compatible with SSB.  indeed, many SSB operators would not know that they're listening to a DSB signal if the signal is reasonably clean.   __ Designed by Peter Parker VK3YE

80 MHz-108 MHz FM Transmitter -  FM transmitter or often called fm transmitter uses 2 transistors in this article uses 2 transistors 2n2222.  if the fm transmitter is in use voltage supply of 9 volt battery and use an antenna whose length is less than 12 inches, then this fm transmitter will be within FCC limits.  Signals from the microphone in the fm transmitter is reinforced by Q1, Q2 with carrier frequency generator is determined by the C5 and L1.  The frequency of the FM transmitter is in the range 80 MHz - 108 MHz.  L1 can be made ​​with as many as 24 e-mail wire wrap and 6 wrap.  The following is a picture series for the fm transmitter fm transmitter referred to in article 2 of this transistor.__ 

80 Watt FM stereo transmitter -  A high quality broadcast transmitter big enough for a medium town!  __ Designed by Manfred Mornhinweg

80 Watt UHF PA, Modified NMT transmitter -  This is not a homemade design !  only modified..
All the stuff in the other small rooms, osc.  pll.  modulation.  drivers and so on has been removed
The PA gives 80 Watt out after the filter, at 28Volt powersupply and 30Watt input drive __ Designed by Thomas Scherrer OZ2CPU

800 meter 2400ft range FM transmitter that fits on top of standard 9V battery -  This is one of the smallest and neatest FM transmitters to be presented as a construction project and it has the advantage of being available as a complete kit of parts.  This will save going to a number of suppliers as no single supplier has all the necessary components __ Designed by Collin Mitchell

807 & 1625 Valves -  data on vacuum tubes 807 and 1625 used in ham radio transmitters.  Describes various pin voltages and different operation modes.  __ 

80m ceramic resonator VXO CW transmitter -  Schematic + Notes __ Designed by Peter Parker VK3YE

80m hexfet power Amplifier -  Schematic only, no circuit description __ Designed by W7ZOI

80m SSB & CW QRP superhet transceiver -  The 80m SSB & CW transceiver an already proven concept used in ATLAS amateur transistorised transceivers from 70's.  The "two-mixer + 1 XTAL filter" design uses the 1st mixer as front-end mixer on receive as well as SSB modulator on transmit.  The second mixer is used as SSB product detector on receive and as a heterodyne mixer on transmit.  VFO and BFO are cross-switched between both mixers with a PIN diode matrix.  Between 1st mixer's output and 2nd mixer's input a crystal filter is placed, followed by an AGC PIN attenuator __ Designed by Aleksander Stare

81 Watt FM stereo transmitter -  A high quality broadcast transmitter big enough for a medium town!  __ Designed by Manfred Mornhinweg

88-108MHz FM audio transmitter / bug -  Schematic only __ Designed by Peter Jakab

8W PLL Stereo Transmitter with LCD -  Very stable FM transmitter based on TSA5511 synthesizer.  Frequency is performed with three buttons through PIC 16F84 microcontroller.  Frequency is displayed on 16x1 LCD.  __ 

98-108MHz FM audio transmitter -  Schematic only __ Designed by Peter Jakab

      <<<         This is the last page of #'s

Got Designs?
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if you want me to link to and/or post your original design.  Thanks.

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


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