The 6N9S double triodes are enclosed in glass bulb and are provided with an octal base and an indirectly heated oxide-coated cathode. The 6N9S double triodes are resistant to ambient temperature from -60 to +70°C and relative humidity of 95 to 98% at +40°C, as well as to vibration with an acceleration of 2.5g and multiple impact up to 35g.
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