Microdion' mono-tube miniature radio receiver

Horace Hurm excelled in the construction of miniature radio receivers whose performance rivalled that of ordinary sets. In 1914 he designed the smallest-ever radio receiver, the Ondophone, then, in the 1920s, the Microdion, ‘the smallest, most sensitive and least expensive of all wireless telephony and telegraphy devices’, which could receive broadcasts from the Eiffel Tower without an antenna. Hurm’s radio receivers were acclaimed when he showed them at the TSF’s first exhibition in Paris in 1922: ‘Who has not heard of his ondophone, his microdion, his microposte and so many other models of various kinds that fit in the hand or pocket yet which enable listening over great distances? His remarkable results were achieved by his in-depth study of each of the receiver’s components and their precise placement. The interior of these receivers is a veritable work of art.’