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Transmitter Circuits

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

Last Updated: November 22, 2021 02:42 PM

Circuits Designed by Dave Johnson, P.E. :
Remote Extender Circuit -  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 Dave Johnson P.E.-June, 2000

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-778-8407




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

QRP HF Transmitter -  I am unable to use packet radio here in Sweden because a SYSOP will not allow me to use FBB software for a PMS system.  As a result all mail to and from me is deleted.  The solution is quite simple, log on to a BBS in another country via HF where they know how to set up a packet system __ Designed by Harry Lythall-SM0VPO

QRP 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 Kang

QRP SSB Transmitter -  This project is relatively simple to construct, and will give a "presentable" SSB signal on the lower HF amateur bands.  Above 14MHz frequency stability may become a little annoying to the listener due to this TX being VFO controlled, but with a little care, and attention to 2nd oscillator component temperature and mechanical stability, operation on 18MHz should be possible. __ Designed by Harry Lythall-SM0VPO

Radio Glen Transmitter -  Not in use any more but ran for a few years.  Worthy of note for the synthesiser, modulator and especially the audio processing.   __ Designed by Henry 

Radio Remote Control using DTMF -  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

Ramsey 25 BA1404 Stereo FM Transmitter -  Stereo FM transmitter based on BA1404 and 145170 frequency synthesizer IC .  __ 

RDS Coder Board using ATmega32 -  This board is a RDS coder using an ATMEL AVR ATmega32.  This board can be controled by a RS232 link, USB interface or SPi.  TA data is displayed wiyth a LED and can be controled by :, Hardware input, RS232, USB, SPI (not yet implemented) __ 

Relative-Humidity Transmitter uses Single Logic IC -  11/08/01  EDN Design ideas:  The low-cost percentage-relative-humidity radio transmitter in Figure 1 operates in a cold-storage warehouse for vegetable storage at temperatures of 1 to 5°C.  it is generally difficult to collect such data from a low-temperature ar Design by Shyam Tiwari, Sensors Technology Ltd, Gwalior, India

Remote Control Transmitter -  Although ready-made remote controls are easy to get, with this project we show how to build on at home.  Features are impressive, with 6 radio channels and long battery life.  Complete with PCB layout.   __ Designed by Projects & Ideas from Nutchip.com

Remote control using VHF Modules -  A few designs for remote control switches, using VG40T and VG40R remote control pair, are shown here.  The miniature transmitter module shown in Fig.1, which just measures 34 mm x 29 mm x 10 mm, can be used to operate all remote control receiver-cum-switch combinations described in this project __ Designed by Radioland.net

Remote Extender Circuit -  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 Dave Johnson P.E.-June, 2000

Remote RF Xmiter -  This device was built into a small (1 1/4 by 2 inch) Radio Shack project box.  it features four push buttons which can produce 2 codes each. (Pushing a button for less than one second sends the first code, holding it for over one second sends the second code.)  __ Designed by Luhan Monat - Mesa Arizona

Repeater Fan Controller -  an 18 kB PDF file __ Designed by Robert Shepard KA9FLX

Resonate CW Speaker -  600 Hz Resonant speaker.  Folded channel box design.  Makes an amazing difference!  __ Designed by Steven "Melt Solder" Weber  KD1JV

RF Actuated CW Monitor -  amateur radio construction projects.   __ Designed by Peter Parker

RF Audio transmitter that operates in the AM broadcast band -  Schematic only __ Designed by Peter Jakab

RF Buffer Stage -  This bufferstage is intended to be used after a BF900 or BF199 (even a BF245) oscillator.  it delivers several milliwatts and is perfect to drive a 2N2219 or 2N4427.  Be sure the coils are really round and can "see" each other: place metalplates between the coils.  The supply voltage is around 12V (typ.13, 8V).  __ 

RF Dummy Load -  make this simple RF Dummy Load for off-air testing of your radio transmitter__ 

RF Four Channels  transmitter & Receiver -  This is a very simple Wireless RF transmitter circuit that consists of the Holtek HT-12E encoder chip and AM 418MHZ-transmitter module (WZ-X01, other similar device can be used).  Using the hybrid RF xmit/receive modules make building the RF remote control a lot easy __ Contact info @ wzmicro.com

RF Power Meter -  RF Power Meter for QRPers __ Designed by Peter Parker VK3YE

RF Power Meter for QRPers -  Circuit only__ 

RF Power Meter for QRPers -  Circuit only__ Electronics DIY

RF Power Meter for the QRPer -  amateur radio construction projects.   __ Designed by Peter Parker

RF Preamplifier -  input needs only several mWatts (e.  g.  BF900) -> 300 mWatts OUT.  This schematic is a often used buffer.  it's easy to build, clean and cheap.  When you want even more power, you can replace the 2N2219a by a 2N4427 or 2N3553.  You can lower the output by adding a little resistor (10.47 Ohm 1/2W) in the emitter line of the 2N2219a.  __ 

RF signal meter with LEDs -  The simple but effective circuit presented here converts an RF input signal into a visible LED indication.  Only discrete components are used.  The circuit can be used as field strength analyser or RF Wattmeter when a 50 ohms resistor is connected between ground and HF (J1).  Calibration required.  Of course you can add extra LED stages in case you want to extend the range.  The second picture shows how the circuit can be build on a very small piece of vero-board.   __ Designed by Ron Zoetermeer, JO22gb, Netherlands

RF Transmitter -  This is probably the simplest radio transimtter that you will find anywhere.  it has a total of five parts and can be constructed into a very samll space __ Designed by Andy Wilson

RF Transmitter Light Sensing -  This transmitter is very simiilar to the Simplest RF Transmitter.   The only difference being the photoresistor placed in series with R1.   This could also be a thermistor or other variablwe resistance sensor. __ Designed by Tony van Roon  VA3AVR

RF transmitter uses AM I encoding -  11/24/99 EDN Design ideas:  Although alternate-mark-inversion (AMi]encoding is well-suited for direct-conversion FM transmission, designers often overlook the technique.  AMi, a three-phase, synchronous-encoding technique, uses bipolar pulses to represent logic ones and no signal to Design by Paul Sofianos

RF/SS Handie Hopper Transmitter Schematic -  Schematic only, no circuit description given__ SSS Magazine

RF-telemetry transmitter features minimal parts count -  6-Jan-05 EDN Design ideas:  Requirements for portable, short-range telemetry systems frequently include low power consumption, small size, and low cost.  The circuit in Figure 1 meets these criteria and uses only three off-the-shelf ICs  and a few passive components.  Although dedicated to conditioning the low-level signal a strain-gauge bridge produces, the circuit can operate with almost any resistive transducer based on Design by Francis Rodes, Eliane Garnier, and Olivier Chevalerias, ENSEIRB Talence, France

Ruthroff's Voltage balun using 4C6 core for HF inverted VEE antenna. -  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

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Got Designs?
Please eMail
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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