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Description: | MULLARD F1 (acid etched on the glass envelope). P (stamped into the copper skirt to indicate the positive connector). G (stamped into the copper skirt to indicate the earth connector). MANU Z Electric Lamp Manufacturing Company. circa 1920 71, Standen Rd, London S.W.18, England DES after PERI,Francois,Captain and BIGUET,Jacques. 1915 France. This early thermionic valve was produced between 1919 and 1920. It is a version of the 'R' type valve and is part of a 7 stage 'amplifier' GLAHM 113542 which is in fact a very early a.m. radio receiver with three untuned h.f. stages, a 'leaky-grid' detector and three a.f. stages. This amplifier was one of the first to come from Mullard. The valve has a round lamp type envelope, set in a copper skirt with meerschaum, and has a four pin connector.The horizontally set elements are a straight tungsten hot filament cathode, a helical coil tungsten or molybdenum grid with a nickel sheath anode. The construction suggests that the valve would be extremely microphonic and that is born out by comments made by J.T. Lloyd about the quality of the sound reproduction when he powered up the set in the 1970's. The apparatus was therefore probably designed for use in wireless telegraphy. | 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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