You will need
  • Transistor П416
  • The variable resistor 47 kOhm
  • Resistor 10 kOhm
  • 2 capacitors 0,022 MF
  • Capacitor 0,033 MF
  • Capacitor 4700 pF
  • A capacitor of 100 pF
  • Capacitor 33 pF
  • Capacitor 51 pF
  • 2 trimmer capacitor, 4-15 pF
  • Choke (L2) 20-60 mcg
  • Carbon microphone
  • High-impedance phones (headphones)
  • Telescopic antenna
  • 40 cm of copper wire 0.5 mm
  • Battery power for 9-12 In
  • Switch ( SA1) — 2 position for 2 groups of contacts (double toggle)
  • A piece of Micarta or PCB for mounting panel
  • Mounting wire
  • The power switch (not shown in the diagram)
  • Toy radio
  • Tools
  • Soldering iron
  • Clippers
  • Pliers
  • Tweezers
  • Drill
  • Drill
Assemble the parts according to the scheme. Adjust coil L1 for the range 27 to 30 MHz. Its winding data are as follows: 11 coils of about 0.5 mm is wound on a disc with a diameter of 10 mm. fine tuning range is carried out with trimming capacitors C1 (receive mode) and C2 (transfer mode) given the fact that the diagram of the switch SA1 is in the receive mode. The adjusting range is held at the reference receiver (for example, child radioprogramm device fabricated). This is easiest to do in a transmission mode. Switching the switch in receive mode, until a loud hiss in the headphones, adjusting the mode of the transistor a variable resistor.
Assemble the parts according to the scheme
Without touching the coil L1 and trimmer capacitor C1 until you get a good signal reception control transmitter (of the same child radios). If you make a walkie-talkie instead of a spoiled, customize it according to available.
The housing design can be any, it depends on the dimensions of the parts. If the casing is metal, the antenna must be protected from contact with the housing of a reliable insulator. As insulator can be used plexiglass.