Guitar FM transmitter:  (electronic circuit added 05/07)

HAM Radio BFO:  circuit diagram of beat frequency oscillator using BF494 and how to listen amateur radio communication on ordinary BC receiver. . (added 01/05)

HeNe Laser Transmitter/Receiver:  (circuit / schematic design added 6/06)

High Power FM Microphone (FM Bug):  (electronic Circuit / Schematic added 10/04)

Infinity Transmitter Schematic and Plans:  Briefly, the Infinity Transmitter is a device which activates a microphone via a phone call. It is plugged into the phone line, and when the phone rings, it will immediately intercept the ring and broadcast into the phone any sound that is in the room. This device was originally made by Information Unlimited, and had a touch tone decoder to prevent all who did not know the code from being able to use the phone in its normal way. This version, however, will activate the microphone for anyone who calls while it is in operation. NOTE: It is illegal to use this device to try to bug someone. It is also pretty stupid because they are fairly noticeable.... (added 4/05)

Infra/Radio Remote Control Transmitter/Receiver:  (circuit / schematic design added 6/06)

Infrared Transmitter and Receiver Schematic Diagrams:  (electronic circuit added 7/03)

Infrared Transmitter Circuit:  (electronic schematic / circuit added 4/02)

Infrared Transmitter for Locomotives:  (circuit / schematic added 6/05)

Laser Torch-Based Voice Transmitter and Receiver:  (circuit / schematic design added 6/06)

Laser Transmitter Schematics:  (electronic circuit added 7/03)

Laser Transmitter/Receiver:  This set of two circuits from the basis for a very simple light wave transmitter. A LASER beam is modulated and then aimed at a receiver that demodulates the signal and then presents the information (voice, data, etc..). The whole thing is very easy to build and requires no specialized parts execpt for the LASER itself. .... (circuit / schematic design added 6/06)

Long Range FM Transmitter #2:  (electronic Circuit / Schematic added 10/04)

Long range FM Transmitter:  (electronic circuit added 10/05)

Low cost relative humidity Transmitter uses single logic IC:  11/08/2001 EDN Design Ideas / (added 6/06)  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 area with high humidity and low illumination. The transmitter design is simple: It uses a readily available, capacitor-type percentage-relative-humidity se... .

Low Frequency Magnetic Transmitter Design:  Microchip Application Note Published 14-Oct-02   (app note added 2/06)

Low Power FM Transmitter:  (electronic diagram added 6/03)

Micro Power AM Broadcast Transmitters:  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. (added 4/02)

Micro Spy with FETs:  (electronic diagram added 6/03)

Micro Spy with TTL:  (electronic diagram added 6/03)

Micro Spy with USW:  (electronic schematic / circuit added 4/02)

MicroPower FM Broadcasting Circuits:  (electronic diagram added 6/03)

Miniature beeper bumper transmitter for vehicle and asset tracking:  (schematic / circuit added 05/07)

Miniature FM Transmitter #1:  (circuit / schematic design added 6/06)

Miniature FM Transmitter #2:  (electronic schematic / circuit added 4/02)

Miniature FM Transmitter #3:  (electronic schematic / circuit added 4/02)

Miniature FM Transmitter #4:  Electronic circuit (added 9/04)

Miniature FM Transmitter:  (circuit / schematic design added 6/06)

Miniature MW Transmitter:  circuit diagram of simple medium wave transmitter using BF494B. This simple transmitter have a range of 200 meters. . (added 9/04)

Miniature tracking transmitter:  (diagram added 05/07)

Monaural FM Transmitter:  AN-543-MonauralFMTransmitter-Analog Device Application Notes  (app note added 6/06) 

Multi Channel RC using CMOS :  This transmitter has no separate on/off switch because the joysticks switch the battery terminal. The receiver has a bigger motor to drive the wheels and a smaller motor to drive the steering which is not proportional. There are two speeds in forward and one in reverse. You could add an extra channel to the receiver by using the spare latch. (added 2/05)

Multiband CW Transmitter:  Circuit / schematic (added 02/05)