Blue-Spot Multidyne All Wave Coil

• Brand: Blue Spot

The Blue-Spot Multidyne all-wave coil is a plug-in coil combining a number of coils suitable for listening in on all wavelengths from 160 to 5,300* metres. An adjustment lever of insulating material operates the multiple switch gear, which switches off at both poles every winding not in use. The windings are the " frameless " twisted basket type. High self-induction, low self-capacity, no oscillation.
What it does; The Multidyne coil entirely dispenses with an expensive collection of coils, and the trouble of changing them. The lever projecting beyond the container avoids hand capacity effects and affords immediate changing from one station to another with beautifully sharp resonance at multiple couple.

The method of marking on the dial the divisions of stage and wavelength makes this operation as simple as it is effective. It is marvelously efficient as a reaction coil because an accurate ratio with all wavelengths is instantly obtained by moving the lever.
Price complete 13/6.

*Note:  In the mid-1920s, F. A. Hughes & Co. Ltd. marketed this coil which was very similar to the Blaupunkt Multidyne all-wave coil from the German company Blaupunkt (Ideal Werke A.G.)

There were differences between the German and British version both in labelling and bandwidth. (See table)
It is not clear if the German Company manufactured a British version of the German Coil or if F. A. Hughes & Co. Ltd.  imported the parts and wound and labelled the coil for the British version.

They then marketed it through various agents throughout Britain under the Blue-Spot Brand.

In questo link sono elencati 12 modelli, di cui 11 con immagini e 3 con schemi.
Elenco delle radio e altri apparecchi della Blue Spot (Brand) F. A. Hughes and Co. & British Blue Spot Co. Ltd.; London