door John Koster

The two HF amplifiers are coupled by neutralised tuned anodes, and all three circuits are tuned by interconnected condensers, with balancers for final adjustment. An elaborate switching arrangement, operated by a single knob (which also controls the filaments) throws long- or short-wave coils into the circuit at will. Screening is complete and the assembly is is built up an a metal chassis. Provision is made for operating the set on batteries or mains supply (AC or DC) in an ingenious manner. The connections are brought out to a row of small screw terminals, to which a multi-way supply cable is connected. The various alterations, such as series connected filaments for DC, extra leads for indirectly heated AC valves or parallel connections for batteries are automatically effected by using the appropriate type of connecting cable. The dial is calibrated in wavelengths as well as in arbitrary units. The set is als supplied with a pedestal base containing a reed-driven cone or a Rice-Kellogg moving coil loudspeaker