Summary
6.3 V indirectly heated cathode, manufactured by Hygrade Sylvania Corporation, Emporium, PA, USA, circa 1950.
The 7A8 is an octode frequency changer designed for use in airborne and other receivers subject to shock and vibration. It has similar characteristics to the 6D8 but the addition of a suppressor grid gives a higher plate resistance, particularly at low operating voltage.
The Loctal base fitted to this valve has a detent on the locating spigot which prevents the valve from coming out of its socket when subjected to vibration such as that encountered in aircraft equipment.
Physical Description
Tubular glass bulb on loctal base.
More Information
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Collection Names
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Collecting Areas
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Acquisition Information
Unknown Acquisition Method from Unknown Source, 1981
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Manufacturer
Hygrade - Sylvania Corporation., Emporium, Pennsylvania, United States of America, circa 1960
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Inscriptions
Top of bulb: 7A8 Side of bulb: SYLVANIA/MADE IN U. S. A./(remnant of leaf logo) Paper label on bulb: 7A8
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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
69 mm (Length), 30 mm (Outside Diameter)
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Keywords