6S53N / 6С53Н — Superminiature Decimeter-Wave Amplifier and Oscillator Triode

High-mu metal-ceramic triode for voltage amplification and oscillation in common-grid decimeter-wave circuits.

Overview

The 6S53N, written 6С53Н in the Russian reference, is a superminiature metal-ceramic triode intended for high-frequency voltage amplification and generation of oscillations in the decimeter wavelength range, specifically in common-grid circuits. The document also specifies the 6S53NV / 6С53Н-В ruggedized variant, with its own electrical tolerances and mechanical and thermal endurance limits.

The source lists an approximate mass of 3 g. The common-grid application distinguishes the 6S53N from general-purpose audio receiving triodes and from other miniature triodes documented primarily for low-frequency amplification.

Construction and Principal Characteristics

The device contains an anode, control grid, and indirectly heated cathode in a metal-ceramic superminiature envelope. The original electrode drawing identifies the anode, grid, cathode, and heater; unlike the grouped connection diagrams for some related tubes, it does not supply a conventional numbered miniature-socket pinout.

The manufacturer's basic measurements use 6.3 V heater, 120 V anode voltage, and 68 Ω cathode resistor.

The high amplification factor and substantial transconductance support the documented high-frequency amplifier application. The 60 MHz input-resistance test is a specified measurement condition, not a complete statement of the tube's operating frequency range.

Common-Grid Decimeter-Wave Applications

The manufacturer explicitly describes voltage amplification and oscillation in the decimeter-wave band with a common-grid circuit.

In a common-grid amplifier, the control grid serves as the common RF reference electrode, with signal input applied to the cathode circuit and output taken from the anode circuit. This configuration changes the input and feedback relationships compared with a grounded-cathode amplifier.

The datasheet does not prescribe a universal operating frequency, gain, or oscillator resonator. Those depend on the associated high-frequency circuit.

Interelectrode Capacitances

The very small feedthrough capacitance is particularly relevant to high-frequency amplifier stability and input-output isolation.

Limiting Operating Conditions

The cutoff-condition anode rating must not be interpreted as a 330 V continuous conducting rating.

Endurance and Environmental Conditions

The manufacturer specifies at least 5,000 hours operating life for the standard 6S53N, 2.5 g vibration acceleration across 10–150 Hz, 35 g repeated-shock acceleration, and ambient operation from −60°C to +125°C.

The separately documented 6S53NV version has a wider vibration range, greater mechanical endurance, and higher maximum ambient temperature.

Comparison with 6S53NV

The 6S53NV is the ruggedized member of the same family. It has 130 ± 20 mA heater current, 9 ± 2.5 mA anode current, 12 ± 2.5 mA/V transconductance, 80 ± 20 amplification factor, and a ≤0.05 pF feedthrough-capacitance limit.

Its environmental qualifications extend to 20 g vibration over 5–5,000 Hz, 150 g repeated shock, 1,000 g single shock, and −60°C to +200°C ambient operation. Its stated minimum service life is 2,000 hours, rather than the standard version's 5,000 hours.

Technical Summary

The 6S53N / 6С53Н is a 6.3 V superminiature metal-ceramic high-mu triode intended for common-grid decimeter-wave voltage amplification and oscillation. Its typical anode current is approximately 9 mA, amplification factor 75 ± 20, and transconductance at least 8.5 mA/V.

The common-grid application, very small feedthrough capacitance, and high-frequency characteristics distinguish it from general-purpose receiving triodes.