Current Part:
27.145 MHz Crystal
2x 2N2222 Transistors
1x 555 Timer
100kΩ Resistor
22kΩ Resistor
1kΩ Resistor
470Ω Resistor
100Ω Resistor
27pF Capacitor
68pF Capacitor
100pF Capacitor
150pF Capacitor
0.1uF Capacitor
2.2uF Capacitor
Push Button
2x 2.2uH Inductor Choke
10uH Inductor Choke
1N4148 Diode
+9v Battery Connector
Ferric Chloride
Clothing Iron
Solder
Soldering Iron
Parts List Details
Most of the parts in this project are discrete passive componenets, however the few active components are described in more detail below.
PC Board
We will make our own PCB for the transmitter so that we can have exact control over all the connection lengths and parts used. 27 MHz is pretty low frequency so there's actually not too too much to worry about.
27.145 MHz Crystal
This is a common frequency band that many governments allow people to use for whatever as long as their transmissions don't exceed 500mw to 1W. Check your local laws to make sure you're not doing anything illegal if you build this.
555 Timer
We will use a 555 timer to generate the 350 Hz on/off signal. Using the timer to generate this signal means only 5 components are needed, saving time and space.
2N2222 Transistor
The two transistors will be used for the carrier frequency generation circuit and for the signal mixing part of the circuit.