Summary
Two dual diode pentodes:
1. The pentode section of this valve which had a semi-remote cut-off characteristic was primarily intended for use in radio receivers as an intermediate frequency (I.F.) amplifier, the diode sections were used as signal detector and automatic volume control (A.V.C.) rectifier. The pentode section was also frequently used as the first audio stage. 2.5 volt indirectly heated cathode.
2. The 2B7 and 6B7 were the first double diode pentodes to be made, combining the functions of IF amplifier, signal detector and AVC rectifier in the one valve. The pentode section has a semi-remote cut-off characteristic. 2.5 V indirectly heated cathode. Manufacturer: Hygrade-Sylvania Corporation, PA, USA.
Physical Description
1. Shouldered glass bulb with top cap and American style small 7 pin base mounted on display block. 2. Shouldered bulb with small seven pin American style base with top cap.
More Information
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Collection Names
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Collecting Areas
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Acquisition Information
Donation from J. C. Liddy, 11 Sep 1950
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Manufacturer
Hygrade - Sylvania Corporation., United States of America, 1933
Note; the date code (J3) indicates 1933 (May) manufacture. -
Inscriptions
1. Bulb: 2B7 Base: Hygrade/J/3 2. Bulb: 2B7 Base: Hygrade Display block: DUO-DIODE-PENTODE 2B7/ Hygrade Made in U.S.A./Heater Cathode; 2.5 volt, 0.8 amp./Used as second detector in Superhet./Receivers about 1936-37/Base:- Standard 7-Pin/Pres. by J.C.Liddy
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Brand Names
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Classification
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Category
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Discipline
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Type of item
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Overall Dimensions
110 mm (Length), 38 mm (Outside Diameter)
Display block not included.
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Overall Dimensions
111 mm (Length), 38 mm (Outside Diameter)
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Keywords