An excellent radio that I had always wanted!
1. Not quite sure what the S.W. 2~4 CAL refers to. There is a Calibration switch that activates an internal crystal oscillator every 125kHz or so so that the analog mechanical drum dial on the left can be adjusted to match the digital display on the right.
2. The MW/SW RF Gain control lets you adjust the external antenna input in case strong signals from 550kHz to 30MHz overload the radio.
3. The Pitch control is for listening to SSB signals (Single Side Band). Amateur radio, marine weather, ship-to-shore telephone, etc. use this method of modulation instead of Amplitude Modulation signals.