CK171 Telephone Conversation Transmitter


GOTO KIT MENUListen to those ‘private’ calls! This is a very popular kit, and you know why. It transmits both sides of the conversation of a telephone call to any FM radio. Comes with all the necessary quick connections to make hook-up fast. No batteries needed!! It takes its power from the telephone line. 100 foot range even through walls. Build one today and let the fun begin! Can be ordered assembled. Measures 2.5cm x 4.5cm


$12.95 $9.90 On Sale!

GOTO KIT MENU Designed with a 5-pin inductor to provide a variable wide transmitting range (88 – 108 MHz) and an excellent frequency stability. Has many applications. You will have a lot of fun with this very reliable fm transmitter. Transmits conversations in the next room, or a crying baby, etc. Requires 4 x “AA” size batteries. Comes with complete instructions, microphone, battery holder, and etched, silk-screened circuit board.
Easy to assemble with soldering iron. Measures 7cm. x 6cm.

Click here to see instuction and assembly manual

CK265 – MP3 / Walkman FM Mono Transmitter with Power Supply (Kit)


This mono FM transmitter can be connected to any type of audio source with a headphone or line output such as a computer, laptop, portable MP3 Player, CD Player or Walkman in order to transmit the sound to any FM receiver. Another great application is to connect the circuit to your portable MP3 Player and listen to the music while in the car using your car’s FM radio. A car cigarette lighter adapter (CBL-12VCAR) is separately available specially for this application so that no batteries are required.

The circuit includes an stereo input which will mix the left and right stereo channels into a single mono signal. The transmitter is easily tunable on the entire FM commercial band (88 – 108MHz) using an adjustable coil and is very stable in frequency. 

The transmitter includes a stereo cable with plug for connection to your computer. The circuit can be powered with an adapter (we recommend using our 9V DC adapter DCA-9200) or using a car cigarette lighter adapter as mentioned above. A DC jack is incorporated right on the board for easy connection.

The transmitter incorporates a specially designed power supply which allows it to be connected to any standard 9V DC adapter without introducing the noticeable “hum” which is usually present when operating a low power transmitter through a wall adapter. The power supply uses two-stage filtering in conjunction with two RF chokes and bypass capacitors for best ripple rejection for a “hum” free operation.

Supply voltage: 9V DC adapter or 12V DC Incoporates stereo-to-mono input circuit Frequency adjustable: 88 to 108MHz Power consumption: 10mA Transmission range: approx. 150m (unobstructed) Input sensitivity: 300mV (Max) Includes stereo cable and plug

R-LB56C Light Beam Communicator Kit w/case

Send Voice, Music, or Data… Over a Beam of Invisible Light!

  • Up to 30 foot range, 1/4 mile with simple lenses!
  • Easily transmits through windows
  • Runs on 9-12VDC
  • Kit includes separate receiver and transmitter
    modules for unlimited possibilities

Transmits a modulated infra-red light beam up to 30 feet with out lenses, up to 1/4 mile using simple lenses. Since the beam is modulated with a 30 KHz carrier (like AM radio) there is no effect from 60 Hz hum that is produced by indoor lighting. Easily transmits through windows – ideal for ‘bugs’ or listening to IR television remote controls. The transmitter can use any type of mike and is very sensitive. The receiver employs an IR PIN diode detector and the is enough power to drive any loudspeaker or earphone. The PC board is cleverly ‘scored’ so you can easily separate the Transmit and Receive sections so they can be used individually to transmit at one location and receive at another. Units run on 9 to 12 VDC. Don’t forget our slick matching case set with red IR end panel.


CK222 FM Stereo Transmitter


GOTO KIT MENU Here it is! The transmitter you need to send that beautiful music or favorite program out to the pool or all over the house and yard or business office. Connect it to your stereo or TV and listen to the music or program with an FM radio, FM portable radio, etc. Transmits in true stereo. You will have your own FM radio station for your home or office. Comes with easy to follow assembly instructions. Can be ordered assembled.

Supply Voltage: 4 X “AA” size batteries
Frequency adjustable: 88 to 98 MHz
Transmission range: 150m (unobstructed)
Input sensitivity: adjustable from 50mV to 1V
Channel separation: >30dB
Includes battery holder and RCA input jacks

R-AM1C AM Radio Transmitter Kit w/ case

R-AM1 $29.90

Entry Level AM Radio Transmitter Kit

A Great Beginners Kit…Your Own AM Radio Station!

  • Tunes entire 550 to 1600 KHz AM band
  • Operates on 9 to 12 VDC
  • Standard line level inputs with RCA phono jacks
  • 100 mW output. Range up to 1/4 mile under optimum conditions

Run your own AM radio station, be the latest talk-show host or top 40 DJ. Ramsey AM radio transmitters operate in the standard AM broadcast band and are easily set to any clear channel in your area. These units are designed very similar to actual commercial radio transmitters, so you’ll learn how the “big boys” operate and use their transmitters. The entry-level AM-1 uses a tunable transmit oscillator and runs the maximum 100 milliwatts of power. No FCC license is required, expected range is up to 1/4 mile depending upon antenna and conditions. Transmitters accept standard line-level inputs from tape decks, CD players or mike mixers, and run on 12 volts DC. You’ll find plenty of uses for these handy little transmitters, from sending radio calls throughout the house to playing games with dedicated Rush Limbaugh listeners. Our AM-1 has an available matching case and knob set for a finished, professional look. Experiment with the fun of AM radio broadcasting!

This product has a shipping weight of 0.21 pounds.