This transmitter has a power of only 2 W, but with a good antenna it can send its signals over distances of several kilometers. As it is a circuit that can be powered by battery, it is an excellent option for mobile use who can also use it on fixed bases and use receivers built into lower power walkie-talkies. A 27 MHz crystal was used in the oscillator for the desired channel. The transistor used at the output is 2SC2078, but equivalents can be used. The coils have the following specifications: L1, L2 and L4 - 8 turns of 0.4 mm wire in the form of 6 mm with ferrite core. L3 is formed by 3 turns of 0.4 mm wire over L2. L5 is formed by 3 turns of 0.4 mm over L4. L6 consists of 2 turns of o wire, 4 mm in the form of 6 mm with adjustable core. The RF coil XRF1 consists of 25 turns of 0.2 mm wire in a 10k ohm x ¼ W resistor. All trimmers are 30 pF maximum capacitance.
