NOS KEN-RAD VT-231 6SN7GT – CKR US NAVY – Bottom D Getter – Weapons Grade – Audiophile Tube

Up for sale is a genuine KEN-RAD CKR 6SN7GT / VT-231, one of the most sought-after vintage dual triodes ever produced.

This tube was manufactured in the USA by Kentucky Radio (Ken-Rad) for U.S. military use (Signal Corps / Navy) during the golden era of vacuum tube production.

⚡ Collector-Grade

Highly regarded among audiophiles and collectors, these early VT-231 tubes are known for their:

- Unique tonal character

- Military-grade durability

- Increasing rarity in strong tested condition

🔥 Construction Features

- Genuine KEN-RAD CKR 6SN7GT

- Military designation: VT-231

- Marked U.S. Navy / Signal Corps

- Black glass (Black Beauty)

- 2-hole black plates

- Heavy foil plate structure

- Bottom D-getter

- Made in USA (Kentucky Radio)

📊 Test Results (AVO CT160 – calibrated)

- Triode sections: 87% / 99%

🔧 Electrical Performance

Measurements:

- Section 1 (87%): ~7.8 mA / 2.25 mA/V

- Section 2 (99%): ~8.9–9.0 mA / 2.6 mA/V

👉 Indicates excellent emission and NOS performance

🎧 Sound Signature

- Deep, authoritative bass

- Thick, textured midrange

- Smooth, slightly darker highs

- Strong drive and dynamics

Often described as:

👉 More powerful and weighty than Tung-Sol

👉 With a more muscular, engaging presentation

- Early VT-231 military production

- One of the most collectible 6SN7 variants

- Distinctive Ken-Rad build (no later equivalent)

- Increasingly scarce in strong condition

- Used in both high-end audio systems and serious collections

📦 Condition

- Tested on calibrated AVO CT160

- Fully functional

- Strong emission

- Original markings visible

- No cracks or damage

🎯 Final Note

A rare opportunity to acquire one of the most respected vintage 6SN7 tubes ever made.

Feel free to reach out for additional photos, questions or matching options.