Valve Gallery - Triode Amplifiers (3)

Valves: 6AT6, 20L1, DH149, ECC81.

As we haven't had too many smaller valves lately here are a page of later valves.  Above is a Brimar 6AT6 with B7G base.  54mm height with 6.3v heater, amplification factor of 70. Shown above is a Mazda 20L1.  B8A base with 67mm height.  12.6v heater with amplification factor of 16.

Shown above is an DH149 from Marconi.  Slightly bigger envelope at75mm with B8G base. 6.3v heater and amplification factor of 100. Shown above is a Mullard ECC81.  The two "C"s indicate that this is a double triode, each capable of amplification factor of 57.  B9A base, and made towards the end of the valve era.  Equivalent (12AT7) is even printed on the glass envelope.  Designed for multipurpose operation, at 6.3 or 12.6v.

Continue to the Diode Valves gallery pages   

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