RAYTHEON Transmitting Triode Tube RK-20A VT-137 VT-81

( Brand: Raytheon ), ( Manufacturer Part Number: RK-20 ), ( Type: Triode ), ( Unit Type: Unit ), ( Country Of Origin: United States )

Review RAYTHEON Rk20a Transmitting Triode Tube Tested Good Vintage

Raytheon RK-20/RK-20A/RK20A Transmitting Triode Tube (VT-137/VT-81): A Legendary Amplifier Tube for High-Fidelity Audio

Step into the realm of vintage audio technology with the Raytheon RK-20/RK-20A/RK20A Transmitting Triode Tube, a legendary amplifier tube that has graced the circuits of high-end audio systems for over half a century. Manufactured by the pioneering Raytheon Company, this tube is synonymous with superior quality, exceptional sound, and timeless design.

The RK-20 series tubes, including the VT-137 and VT-81 variants, are renowned for their ability to deliver a rich, warm, and detailed sound that sets them apart from contemporary tubes. With an operating voltage of 350V, these tubes are designed to provide a clean, powerful signal amplification for audiophiles seeking the ultimate in high-fidelity sound reproduction.

The RK-20 tubes are built with Raytheon's proprietary vacuum technology, ensuring a long-lasting and stable vacuum environment that minimizes microphonic noise and maintains consistent performance over time. The tube's large glass envelope houses a high-quality filament and triode elements, designed to deliver a broad frequency response and low distortion, resulting in a smooth, natural sound that brings your music to life.

These tubes are also known for their robust construction, featuring a sturdy metal base and a heat-resistant coating on the glass envelope. The RK-20 series tubes are a testament to Raytheon's commitment to producing high-quality, reliable components that stand the test of time.

Whether you're restoring a vintage audio system or enhancing a modern setup, the Raytheon RK-20/RK-20A/RK20A Transmitting Triode Tube is an excellent choice for audiophiles seeking a unique, high-performance component that delivers a truly exceptional listening experience. Embrace the warmth, depth, and detail of yesteryear's audio technology with the Raytheon RK-20 series tubes.

Pros and Cons of Buying Raytheon RK-20 RK-20A RK20A Transmitting Triode Tube (VT-137 VT-81)

1. Historical Significance: These tubes are a part of the rich history of radio transmission, with Raytheon being a well-known and respected manufacturer in the field.

2. Vintage Appeal: The RK-20 series tubes have a distinctive, vintage aesthetic that may appeal to collectors and enthusiasts.

3. Durability: Raytheon is known for its high-quality products, and these tubes are likely to be robust and long-lasting if maintained correctly.

4. Availability: Despite being vintage, these tubes are still relatively easy to find on the secondary market.

1. Obsolete Technology: Radio tubes like the RK-20 series have been replaced by more modern, solid-state components. This means they may be less efficient and more prone to failure.

2. Limited Compatibility: These tubes are designed for specific applications, which may be hard to find in modern equipment.

3. Higher Cost: Compared to modern components, vintage tubes like the RK-20 series can be more expensive due to their rarity and the cost of maintaining them.

4. Maintenance: Tube-based equipment requires regular maintenance, including replacing the tubes periodically.

The Raytheon RK-20 RK-20A RK20A Transmitting Triode Tube (VT-137 VT-81) is a valuable piece of radio history with a unique aesthetic appeal. However, its use is limited by its obsolete technology, and it may be more expensive and require more maintenance than modern alternatives.

If you are a collector or a radio enthusiast, the RK-20 series tube can be a worthwhile addition to your collection. However, for general radio or communication needs, it is recommended to consider modern, solid-state alternatives for their efficiency, compatibility, and lower maintenance requirements.

Details:

ALL 3 LIGHT UP UNDER POWER CLEAN TIGHT BASES ONE APPEARS TO BE MISSING THE CAP. 3 RAYTHEON RK-20 RK20A Transmitting Triode tube VT-137 VT-81 TESTED GOOD VINTAGE.

part #: rk20 prices

• $20.00-$48.77

specifications tubesocketvintagego:

• brand: Raytheon
• mpn: Rk-20
• type: Triode
• unit type: Unit
• country of origin: United States

seller tubesocketvintagego:

• rating: 100.0%
• # reviews: 8584
• city: Brunswick, Maryland

returns tubesocketvintagego:

• method: Money back
• policy: Returns Accepted
• paid by: Seller
• time: 30 Days

payments tubesocketvintagego:

• wallet: Paypal
• other
• credit card: Discover

offer tubesocketvintagego:

• availability: In Stock
• started: January 30, 2026
• quantity: 1
• sold: 0
• options: Ship-to-home
• best offers: True

general tubesocketvintagego:

• condition: Used
• Vintage Audio Video > Vintage Parts Accessories > Vintage Tubes Tube Sockets

shipping tubesocketvintagego:

• cost: $0.00
• class: Standard
• type: Fixed
• transit: 5-11 Days
• service: USPS Ground Advantage
• carrier: USPS

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