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. . . . [by Guy Roels ON6MU]
AM DSB Transmitter for Hams - circuit diagram of simple double side band suppressed carrier (DSBSC) transmitter for hams.
Circuit uses crystal oscillator, crystal can be switched for multi band operation. . .
AM Transmitter - The circuit is in two halfs, an audio amplifier and an RF oscillator. The oscillator is
built around Q1 and associated components. The tank circuit L1 and VC1 is tunable from about 500kHz to 1600KHz. . .
. [Andy Collison]
Automicro TM02 high power
transmitter module schematic - . . . [Peter Jakab, Electrical Engineer,
Engineer of Informatics]
Cardboard AM Radio Resonant Loop
Passive Booster Antenna - An excellent use for copper wire, a trimmer
capacitor and some lovely cardboard. . . . [Henry (last name not given)]
Low-Range AM Radio Transmitter - Here is a simple radio transmitter for transmission up to 25 metres. It is basically an AM
modulator whose signal can be received on the normal AM radio. It can also be used as an AM radio tester. . . . [©
EFY Enterprises Pvt. Ltd. All rights reserved.]
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.
. . [Bill Bowden]
One Watt AM transmitter for the 10
meter band (28MHz) - In this project, you will make a simple 3-stage
low-power broadcast-type circuit, using a crystal oscillator integrated circuit and an a collector modulated AM
oscillator with amplifier. You can connect the circuit to the an electred microphone or amplified dynamic microphone.
Using an electred microphone is shown (in gray) in the diagram below. (no amplified dynamic microphone has a to low
output voltage to work. at least 100mv is needed). You could also add a LF preamp stage of one transistor to allow
connecting a dynamic microphone directly. You'll see that you can receive the signal through the air with almost any
AM radio receiver. Although the circuits used in radio stations for AM receiving are far more complicated, this
nevertheless gives a basic idea of the concept behind a principle transmitter. Plus it is a lot of fun when you
actually have it working! Remember that transmitting on the 10 meter band you'll need a valid radioamateur
license!!. . . [by Guy Roels ON6MU]
Powerful AM Transmitter - . . .
SAW-based 434MHz transmitter
schematic with RO2101 - . . . [Peter Jakab, Electrical Engineer,
Engineer of Informatics]
SAW-based transmitter - . . . [Peter Jakab, Electrical Engineer, Engineer of Informatics]
SAWR-based transmitters - . . . [Peter Jakab, Electrical Engineer, Engineer of Informatics]