design a local oscillator for an amateur radio transceiver that is to operate on the 1.8-2.0, 3.5-4.0, 7.0-7.3, 10.1-10.15, 14.0-14.35, 18.068-18.168, 21.0-21.45, and 28.0-29.7 MHz amateur bands. The tuning control is required to provide a uniform, linear change in frequency for a fixed rotation of the knob, e.g., 25 kHz per revolution at any operating frequency.
• You are considering three options for controlling the frequency:
- Adjusting the capacitance in an LC oscillator
- Adjusting the inductance in an LC oscillator
- Changing the capacitance of a varactor diode by varying the control voltage
• Propose a transceiver structure and tuning method that can meet these objectives. Research and specify the components (e.g., capacitors, inductors, varactors) for your chosen design. Note: previous designs are a good starting place. Major manufacturers of similar equipment (past and present) include Collins, Hallicrafters, Hammarlund, Icom, Kenwood, and Yaseu.