The Svetlana GP-5 (ГП-5) is a glass-envelope beam power triode intended for use as a shunt regulator or pulse modulator in high-voltage systems. It features an anode operating voltage of 30 kV and a plate dissipation of 37.5 watts. Originally intended for color-TV voltage stabilization, the GP-5 is similar to the Telefunken ED500 and may be used to retrofit equipment which uses the American type 6BK4 or other high-voltage beam triodes. It is a New Old Stock (NOS) item, never used, and is manufactured by the Svetlana plant in St. Petersburg, Russia.

Key Features & Specifications

• Name: GP-5 / ГП-5
• Type: beam power triode (high-voltage regulator)
• Application: shunt regulator, pulse modulator in high-voltage systems
• Cathode: oxide-coated, unipotential (indirectly heated)
• Heater voltage: 6.3 V (± 0.6 V)
• Heater current: 210 mA (± 20 mA)
• Heater-cathode voltage, peak: ±200 V
• Amplification factor (nominal): 2750
• Transconductance (nominal): 700 µS (0.7 mA/V)
• Plate resistance: 3.9 MΩ
• Input capacitance: 4.0 pF
• Output capacitance: 1.5 pF
• Feedback capacitance: ≤ 0.1 pF
• Base: standard magnoval, glass button (9-pin)
• Anode cap: approx. 3/8 in (9 mm) diameter
• Operating position: any (vertical for convection cooling)
• Height of glass envelope: 100 mm
• Diameter of glass envelope: 46 mm
• Overall height: 125 mm
• Net weight: 115 g

Maximum Ratings

• Max anode voltage: 30,000 V
• Max anode dissipation: 37.5 W
• Max anode current, continuous: 2.0 mA
• Max grid voltage: −450 V
• Max grid-circuit resistance: 3 MΩ
• Max envelope temperature: 250 °C

Applications & Compatibility

• Primary use: high-voltage shunt regulator in color television sets and other high-voltage equipment.
• Retrofit use: direct replacement for the American 6BK4 and similar high-voltage beam triodes.
• Equivalent: Telefunken ED500.
• Note: the GP-5 is known as a powerful source of X-ray emission in consumer equipment; proper shielding and safety precautions are essential.

Condition

• Status: NOS (New Old Stock). Never used.
• Origin: Made in Russia by the Svetlana plant (St. Petersburg).

Why Choose This Tube?

The GP-5 offers a rare combination of extreme voltage capability and compact construction, making it a practical choice for restoring vintage color televisions or servicing high-voltage regulator circuits. Its electrical characteristics are closely matched to the Telefunken ED500 and the American 6BK4, allowing it to serve as a direct retrofit in equipment designed for those types. For experimenters working with high-voltage supplies, the GP-5 provides a robust, glass-envelope beam triode that can withstand anode voltages up to 30 kV while dissipating up to 37.5 W. As a NOS Svetlana product, it represents reliable Soviet-era engineering for specialized high-voltage applications.