Abstract: A tuning unit with a bandswitch for high frequency receivers having a potentiometer system for the control of capacity diodes is disclosed. The potentiometer system includes a plurality of parallelly disposed resistance paths on which wipers can be moved by means of screw tuning spindles mounted beside one another in a common housing made of an insulating material. The bandswitch is formed of metal wires and is associated with each tuning spindle. The tuning spindles are joined for rotation with sleeves simultaneously forming the operating knobs which are carried in apertures in the front plate and each have a flange engaging the back side of the front plate about the apertures. The flange is slightly larger than the cross section of the apertures and tapers conically away from the back side of the front plate.

Abstract: Attenuation equalizer in the circuit of an adjustable four-terminal network for correcting the frequency-related attenuation curve of cables including a bridged T circuit containing ohmic resistances and having two fixed ohmic series resistance, preferably of equal resistance value, bridged by a bridging impedance, the bridging impedance being a series-resonant circuit having an inductance, a condenser and a variable parallel resistance wherein the shunt impedance is a parallel-resonant circuit having an inductance, a condenser and a variable series resistance, the latter being adjustable by means of a common traversing device.