Nuvistor Tubes (all numbers) ·Triode
High-frequency triode for wideband amplification, oscillation, conversion, or RF power service in VHF/UHF electronic equipment.
A high-transconductance metal-ceramic triode intended for use in general radio equipment, with a compact multi-terminal electrode structure.
The 6S65N, designated 6С65Н in the Russian reference, is a superminiature metal-ceramic triode for universal radio equipment. The manufacturer documents a high-transconductance triode with approximately 8.5 mA anode current and 15 mA/V transconductance at the specified 150 V anode operating point.
The tube's compact metal-ceramic construction is accompanied by detailed electrical, noise, interelectrode-capacitance, environmental, and endurance specifications.
The original electrode diagram identifies the anode, control grid, cathode, heater, and additional electrode-associated connection groups. The illustrated terminal grouping includes 1, 2, 3 for the anode, 10, 11, 12 for the control grid, 13, 14, 15 for the cathode, and 16 and 18 for the heater, with other contacts shown around the envelope.
This is a specialized superminiature metal-ceramic structure, not conventional noval or octal receiving-tube basing. The published mass is approximately 5 g.
The manufacturer's principal test conditions are 6.3 V heater, 150 V anode, and 39 Ω cathode resistor.
| Characteristic | Published value |
|---|---|
| Heater current | 135 mA, +15/−25 |
| Anode current | 8.5 mA, +4/−2.5 |
| Anode current at +2.5 V grid voltage | 50 µA, as printed |
| Grid reverse current at −1.5 V | ≤0.1 µA |
| Transconductance | 15 mA/V, +3.5/−3 |
| Input resistance | 3.5 kΩ |
| Equivalent internal noise resistance | 0.2–0.35 kΩ |
| Vibration-induced noise voltage | ≤80 mV |
The manufacturer's acceptance criteria include grid reverse current ≤1.5 µA and transconductance ≥9.6 mA/V.
The relatively high transconductance indicates substantial control of anode current by the grid at the stated operating point. The input-resistance and noise figures are separate measurements and should not be confused with ordinary DC grid-circuit resistance.
| Measurement | Value |
|---|---|
| Input capacitance | 5.8 ± 1.2 pF |
| Output capacitance | 3.5 ± 0.7 pF |
| Feedthrough capacitance | ≤0.5 pF |
These values are relevant to input loading and feedback in the radio-frequency circuits for which the tube is intended.
| Parameter | Limit |
|---|---|
| Heater voltage | 5.7–7.0 V |
| Anode voltage | 200 V |
| Anode voltage at cutoff | 300 V |
| Cathode-to-heater voltage | ±100 V |
| Cathode current | 15 mA |
| Anode dissipation | 2.2 W |
| Grid dissipation | 0.02 W |
| Grid-circuit resistance | 1 MΩ |
| Envelope temperature | 250°C |
The cutoff-condition anode rating is not an unrestricted conducting plate-voltage limit.
The manufacturer specifies 15 g vibration acceleration over 5–2,500 Hz, 150 g repeated shock, 1,000 g single shock, and 150 g sustained acceleration. The ambient operating range is −60°C to +200°C.
The published minimum operating life is 2,000 hours.
The Russian reference includes anode-current versus grid-voltage curves for several anode voltages and anode-current versus anode-voltage curves for several grid biases. These show the dependence of anode current on operating voltage and control-grid bias.
The 6S65N / 6С65Н is a 6.3 V superminiature metal-ceramic triode for general radio equipment, with approximately 135 mA heater current, 8.5 mA anode current, and 15 mA/V transconductance at the published 150 V anode test point.
Its high transconductance, compact specialized electrode construction, capacitance and noise specifications, and ruggedized −60°C to +200°C environmental range distinguish it from ordinary glass-envelope receiving triodes.
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
1 physical section, each with unique specifications.
Section 1
Promoted values translated from the filename-designated Russian entry only.
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
Nominal heater voltage
6.3 V
Published source value
Nominal heater current
135 mA
Published source value
Transconductance
15000 uS
Published operating point
Guaranteed service life
2000 h
Published source value