Cunningham 71A - 1930's - Globe Tube - Engraved Base - Power Triode - "Satisfaction Guaranteed"

One Cunningham 71A Power Triode Tube

Used – Excellent Condition (1930s Production)

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Etched (Engraved) Black Base

Globe / Balloon / S-Type Envelope

Date Code: E 4. = 1930s

Includes White Tube Box

Appearance: Well-Preserved Vintage Example

Inv. # 18-3 77948130

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🧪 TEST RESULTS (Triplett 3444)

• Minimum Good Gm: >850

• Average New Gm: ~1700

• This Tube: 1800 Gm

• Plate Current: 17.6 mA

• Strong Emission • Balanced Triode Sections

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🧠 HISTORICAL CHARACTER

• Classic **directly heated triode**, designed for use in early audio and radio gear

• Globe (S-shaped) envelope and etched base signify **pre-WWII RCA-era craftsmanship**

• Collectible and functional — ideal for restoring early single-ended triode (SET) amps, vintage radios, and intercom circuits

• Highly regarded for its **warm, articulate tone** and **stable plate characteristics**

🎯 The 71A is prized by enthusiasts seeking **authentic triode tone from America’s golden age of tube manufacturing.** This one is fully verified and tested with confidence.

Ships fast, packed securely, and handled with care throughout storage.