Fading control potentiometer with resistance coil - has coil turns in regions near to run-up rails wound at greater pitch than in middle section

The fading control is partic. intended for stereo loudspeakers in motor vehicles, in order to control the tone middle point inside the vehicle compartment, while providing a high degree of sensitivity. The resistance wire coil is mounted on an insulating support and connected to run-up rails. On the latter, as well as the coil, slides a double contact slider in a manner resembling a potentiometer. The turns (6) of the resistance coil are wound with a greater pitch in the sections (A, C) near the run-up rails (4, 5) than in the middle section (B) of the coil (7). The entire coil is pref. wound of the same continuous resistance wire. The ends of the support are provided with terminal eyelets (2, 3) for soldering, connected or forming a transition to the run-up rails. The total resistance of the coil may be 40 ohms. The slider (8) has a lead (12).