Plug-in Coil

Burndept Coils. Patent No.168249.

Excerpt from the Gecophone Catalog:

"One of the most efficient types of multi-layer coil now on the market. Their construction provides for ample air space between each layer, thus reducing the distributed capacity to about one-half that of other types of multi-layer coil. Coils S.1 to S.4 are single layer coils, wounf on ebonite, and specially designed for the reception of broadcasting and Amateur Telephony, as they cover a wavelength range of 150 to about 800 metres on an average P.O. aerial. Coils 75 to1000 are patent multi-layer coils, and cover all wavelengths from about 750 to 20000 metres."

The following values were available:

In questo link sono elencati 93 modelli, di cui 61 con immagini e 28 con schemi.
Elenco delle radio e altri apparecchi della Burndept Ltd. London