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Description: | CONSTANT SQUARE PEAK PAT PEND REG DESIGN No 763904 Varley TUNING COIL (Trade mark etc on the centre band of the coil) MANU Oliver Pell 1935 Cambridge Row, Burrage Road, Plumstead, London, S.E.18, England. DES after FARADAY,Michael. August 1831 The Royal Institution of Great Britain, 21, Albermarlle Street, London, England. This is a "Varley" radio reception tuning coil. It was used, in conjunction with a variable air-gap capacitor, to multiply the voltage of the radio signals received at the arial to a level that could be used in the input electrode, control grid, of the first triode valve in the signal amplifier stage. This coil was designed for use in long and medium wave radio receivers called the Varley Square Peak range. The first was the AP 34,. made in 1934 it was a three valve amplifier set using as V1 an S4VA screened grid tetrode, V2 a 345V triode detector, V3 a PEN4V pentode and a DW3 rectifier. The second was the AP38 was a 5 valve AC Mains Superhet set using an MM4V screened gride tetrode as V1, V2 a Pen4V , as V3 an MM4V, as V4 a 354V , as V5 a Pen4V and a DW3 rectifier. The third was the Superhet AP40 AC mains 5 valve radio-gram based on the same circuitry as the AP38. An AP46 was produced but as yet nothing is known of this set.
The Varley trademark was based on the name of a famous 19th century electrical and telegraph engineer.Cromwell Fleetwood Varley (1828-1883) was the son of Cornelius Varley and like Michael faraday was a Sandemanian, a member of fundamentalist protestant sect. Cornelius' brother Samuel was an optician, instrument maker and inventor. Cromell, so named because he was descended from Oliver Cromwell and General Fleetwood had studied telegraphy on leaving school and worked in the Electric Telegraph Company, later known as the Electric and International Cable Company, for twenty three years. He was first appointed in 1846 and left when the telegraph companies were appropriated (nationalised) by the Government in 1870. The act past in 1868 and amended in 1869 gave the Post-master General a monopoly of the telegraph service and by January 1870 he had complete control of the entire system. Varley had worked on the Anglo-Dutch cables in 1853 and had been a pioneer of electrical measurement for fault detection. He also confirmed Thomson?s law of squares in 1860. | License: | http://www.hmag.gla.ac.uk/spirit/rights/ | Publisher: | Hunterian Museum and Art Gallery, University of Glasgow | Rights holder: | Hunterian Museum and Art Gallery, University of Glasgow | Subjects: | SCIENTIFIC COLLECTION : | Source: | Hunterian Museum | Creator: | Hunterian Museum and Art Gallery, University of Glasgow | Identifier: | http://www.huntsearch.gla.ac.uk/cgi-bin/... | Language: | en-GB | Go to resource |
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