This transmitter circuit operates in shortwave HF band (6 MHz to 15 MHz), and can be used for short-range communication and for educational purposes. The circuit consists of a mic amplifier, a variable frequency oscillator, and modulation amplifier stages. Transistor T1 (BF195) is used as a simple RF oscillator. Resistors R6 and R7 determine base bias, while resistor R9 is used for stability. Feedback is provided by 150pF capacitor C11 to sustain oscillations. The primary of shortwave oscillator coil and variable condenser VC1 (365pF, 1/2J gang) form the frequency determining network.