6S52N / 6С52Н — Superminiature Metal-Ceramic High-Frequency Triode

A compact Soviet triode for voltage amplification and oscillation, with a separately specified ruggedized 6S52NV / 6С52Н-В variant.

Overview

The 6S52N, written 6С52Н in the Russian technical reference, is a superminiature metal-ceramic triode intended for voltage amplification and generation of oscillations. The same source also documents the 6S52NV / 6С52Н-В, a related version with enhanced vibration, shock, and ambient-temperature qualifications.

The manufacturer describes a compact device weighing approximately 3 g. Its characteristic data include relatively high amplification factor, appreciable transconductance, and high-frequency input resistance, making it distinct from ordinary low-frequency glass receiving triodes.

Construction and Connections

The tube has an anode, control grid, and indirectly heated cathode. The Russian electrode drawing labels a for anode, c for grid, к for cathode, and п for heater.

The illustrated connection groups are 1, 2, 3 for the anode, 4, 5, 6 for the grid, 7, 8, 9 for the cathode, and 10 and 12 for the heater. This is a metal-ceramic superminiature construction, not an ordinary noval receiving-tube socket arrangement.

Heater and Basic Characteristics

The manufacturer specifies measurements at 6.3 V heater, 120 V anode, and 130 Ω cathode resistance.

For the ruggedized version, the source additionally specifies transconductance ≥6.5 mA/V at 5.7 V heater voltage, equivalent noise resistance ≤0.4 kΩ, and a manufacturer acceptance criterion limiting transconductance change to 35%.

The grid-current and cathode-to-heater leakage values are separately defined tests and should not be confused with the normal anode current.

High-Frequency Amplification

The source explicitly describes the 6S52N as a triode for voltage amplification and oscillation generation. It specifies an input resistance at 60 MHz and includes plate and transfer curves for the ruggedized version.

The published amplification factor near 60–64 and transconductance near 7–10 mA/V support its high-gain receiving-amplifier role. These are characteristic values, not a guarantee of a particular loaded-stage gain at all frequencies.

Interelectrode Capacitances

The manufacturer distinguishes the two versions' capacitance tolerances. These are relevant to the loading and feedback behavior of high-frequency amplifier and oscillator circuits.

Maximum Operating Ratings

The reference gives the following limiting conditions for the family:

The 330 V figure applies to the cutoff condition, not unrestricted conducting operation. The normal anode-voltage limit is 120 V.

Environmental and Endurance Characteristics

The manufacturer specifies at least 5,000 hours of operating life for both variants.

These distinctions identify the -В variant as the more extensively qualified version for mechanical and thermal stresses.

Characteristic Curves

The Russian reference includes anode-current curves for the 6S52NV at different control-grid voltages, along with transfer curves for different anode voltages. These show how plate current changes with grid bias and plate voltage and supplement the tabulated gain and transconductance characteristics.

Technical Summary

The 6S52N / 6С52Н is a 6.3 V superminiature metal-ceramic triode intended for high-frequency voltage amplification and oscillation, drawing approximately 130 mA heater current and providing approximately 8 mA anode current at the specified 120 V operating point.

Its documented high amplification factor, 60 MHz input-resistance specification, small interelectrode capacitances, and compact 3 g construction distinguish it from conventional glass receiving triodes. The related 6S52NV adds separately qualified vibration, shock, and high-temperature endurance.