6E12N / 6Э12Н — Metal-Ceramic High-Frequency Amplifier Tetrode
An indirectly heated Soviet miniature tetrode for high-frequency voltage and power amplification, with a related vibration-qualified 6E12NV / 6Э12Н-В variant.
Overview
The 6E12N, written 6Э12Н in the original Russian reference, is a high-frequency tetrode intended for amplification of voltage and power at high frequencies. Its construction uses a compact metal-ceramic envelope with rigid electrode connections. The manufacturer reference also covers 6Э12Н-В, transliterated 6E12NV, a related version with separately specified vibration, shock, and high-temperature endurance.
The source provides separate numerical characteristics for the standard and -В versions. These should be preserved rather than assuming every specification is identical.
Electrode Structure and Mechanical Construction
The 6E12N contains an anode, a first or control grid, a second or screen grid, and an indirectly heated cathode. The original drawing labels A for anode, C1 for first grid, C2 for second grid, K for cathode, and П for heater.
The manufacturer drawing identifies electrode connections in groups: anode at the upper connection; second-grid connections 1, 2, 3; first-grid connections 4, 5, 6; cathode connections 7, 8, 9; and heater connections 10 and 12. This is the source's illustrated terminal grouping, not a conventional nine-pin miniature receiving-tube basing.
The published mass is approximately 4 g. The metal-ceramic construction and grouped connections distinguish the tube from ordinary glass-envelope receiver tetrodes.
Heater and Test Conditions
The reference specifies basic measurements at 6.3 V heater voltage, 120 V anode voltage, 50 V screen-grid voltage, and 68 Ω cathode resistance.
The two versions have similar nominal operating conditions but different transconductance and anode-current tolerance statements. The 6E12NV sheet additionally specifies a first-grid reverse-current test at −1.6 V and 0.5 kΩ grid resistance, with a limit of ≤0.1 µA.
High-Frequency Performance and Noise
For the standard 6E12N, the source specifies an equivalent noise resistance of ≤1 kΩ at 30 MHz. This is a particular RF noise measurement and should not be generalized into a complete broadband noise-figure specification.
The standard tube's vibration-induced noise voltage is specified as ≤40 mV with a 2 kΩ anode load, at 50 Hz mechanical vibration and 2.5 g acceleration.
For the 6E12NV, the reference gives a more extensive vibration-noise qualification. At 15 g acceleration, the specified maximum noise voltages vary by frequency and by the proportion of tubes meeting each threshold:
These are manufacturer acceptance criteria for vibration-induced output, not normal RF signal amplitudes.
Interelectrode Capacitances
The exceptionally small published feedthrough capacitance is important to high-frequency tetrode operation because it characterizes unwanted coupling between input and output electrode systems. The distinction between the two versions is small but explicitly documented.
Limiting Operating Conditions
The source gives the following limiting values for the family:
The 6E12NV additionally specifies a 110 V screen-grid limit, a 330 V screen-grid condition when cut off, and 100 V cathode-to-heater voltage. The standard version's table does not separately state these three limits; they should not automatically be copied across without manufacturer confirmation.
The cut-off voltage limits are separate from the normal conducting operating limits.
Service Life and Environmental Qualification
The standard 6E12N is specified for at least 5,000 hours of operation. The 6E12NV has separately stated endurance of at least 500 hours at 200°C ambient and at least 1,000 hours at normal ambient temperature.
The manufacturer gives a standard-tube multiple-shock acceleration of 35 g, while the 6E12NV is rated for 150 g repeated shock and 1,000 g single shock.
The operating ambient ranges are −60°C to +125°C for the standard 6E12N and −60°C to +200°C for the 6E12NV. These are substantial distinctions between the versions.
Characteristic Curves
The original Russian reference includes plate-current curves for the 6E12NV, showing anode current versus anode voltage at different first-grid biases, with 6.3 V heater and 50 V screen-grid conditions. It also includes a transfer curve of anode current versus first-grid voltage at 120 V anode and 50 V screen.
These curves illustrate the effect of control-grid bias on anode current and the relatively flat plate-current behavior over part of the conducting range typical of the documented tetrode operation. They complement, rather than replace, the tabulated measurement points.
Technical Summary
The 6E12N / 6Э12Н is a compact 6.3 V metal-ceramic high-frequency amplifier tetrode, with approximately 140 mA heater current, 10 mA typical anode current, and 9.5 mA/V nominal transconductance at the published 120 V anode / 50 V screen test point.
Its low feedthrough capacitance, RF noise specification, high-temperature construction, and high-frequency voltage and power amplification purpose distinguish it from general-purpose low-frequency receiving tubes. The related 6E12NV / 6Э12Н-В is separately characterized for vibration, shock, and elevated ambient temperature operation, and should retain its own manufacturer-specific limits.
