Methods and devices for demodulators for continuous phase modulation waveforms. The guide unit includes upper and lower sliding bushings axially spaced apart and disposed within a cavity of the outer tube and guide sliding movement of the inner tube. The U-shaped pre-bent parts may be each be flat conductors. A second complimentary portion of the figure, into which a second pair of reference points has been incorporated, is placed behind the drawing surface of the easel.