16LO2I — Dual-Gun Electrostatic Cathode-Ray Tube

The 16LO2I (16ЛО2И) is a specialized, Soviet-manufactured cathode-ray tube (CRT) designed for the visual observation and registration of electrical processes in a wide range of radio-technical devices. It features electrostatic focusing and electrostatic deflection of the electron beams, producing a green screen display with a medium persistence of no more than 0.1 seconds.

Overview

The 16LO2I is distinguished by its dual-gun (dual-beam) internal construction, incorporating two independent electron-optical systems (designated as system "a" and system "b"). This configuration allows the simultaneous display and comparison of two separate electrical signals. The tube utilizes electrostatic fields for both focusing and deflecting the electron beams, ensuring high-speed response suitable for oscillographic and signal-registration applications.

Electrode Configuration and Pin Connections

The 16LO2I features a multi-pin base layout to accommodate the independent electrodes of both electron gun assemblies, alongside dedicated deflection plates. The pinout configuration is defined as follows:

In addition to the base pins, the tube features several dedicated external connections:

• A3: Third anode lead
• Y1a: Signal plate, system a
• Y1b: Signal plate, system b
• Y2a: Signal plate, system a
• Y2b: Signal plate, system b

The physical dimensions and mass of the tube are:

• Maximum overall length: 450 mm
• Maximum screen size: 117 mm × 137 mm
• Maximum mass: 1900 g

Electrical and Optical Specifications

Under standard operating conditions, the 16LO2I exhibits the following electrical and optical parameters:

• Heater voltage: 6.3 V
• Heater current: 0.54 to 0.66 A
• First anode voltage: 350 to 650 V
• Second anode voltage: 2000 V
• Third anode voltage: 3500 V
• Negative cutoff voltage: 40 to 100 V
• Focused line width (at screen center): ≤ 0.8 mm
• Modulation voltage: ≤ 45 V

Absolute Maximum Ratings and Lifetime Performance

To ensure reliable operation and prevent premature failure, the operating parameters of the 16LO2I must be maintained within the following absolute limits:

Lifetime Performance (1000 Hours of Operation)

After a standard operating period of 1000 hours, the tube's parameters are specified to remain within the following limits:

• Focused line width (at screen center): ≤ 1.2 mm
• Parasitic emission brightness: ≤ 0.2 cd/m²
• Modulation voltage: ≤ 50 V

Environmental and Mechanical Tolerances

The 16LO2I is designed to withstand rigorous mechanical and environmental conditions during operation and storage:

Mechanical Tolerances

• Vibration loads: Frequency range of 1 to 60 Hz with an acceleration limit of 24.55 m/s² (equivalent to 2.5 g).
• Multiple shocks: Acceleration up to 147 m/s² (15 g) with a shock duration of 2 to 15 ms.

Environmental Tolerances

• Ambient temperature: 213 K to 343 K (or 228 K to 343 K under specific operating conditions).
• Relative humidity: Up to 98% at an ambient temperature of 298 K.
• Low atmospheric pressure: Down to 70,000 Pa.
• High atmospheric pressure: Up to 297,198 Pa.

Storage Conditions

When stored in the manufacturer's original packaging or when integrated into equipment, the storage environment must be a heated warehouse maintained at a temperature between 274 K and 313 K, with a relative humidity not exceeding 80% at 298 K.

Application and Installation Guidelines

When integrating the 16LO2I into electronic systems, several critical design and handling rules must be observed:

1. Simultaneous Limits: Operation of the CRT at two or more absolute maximum limits simultaneously is strictly prohibited.
2. Mechanical Mounting: The tube must be secured within the equipment using shock-absorbing pads. Direct contact between the glass bulb of the CRT and any metallic structural parts of the equipment is not permitted.
3. Automatic Beam Blanking: Designers are strongly recommended to implement an automatic beam blanking (cutoff) circuit. This circuit must automatically cut off the electron beams if the sweep generator fails, preventing screen burn-in and tube failure during power-on, power-off, or sweep circuit malfunctions.
4. Breakdown Protection: The associated circuitry should include protective measures against short-term electrical breakdowns within the CRT that do not otherwise cause permanent device failure.
5. Tropical Climate Preparation: For units intended for use in tropical climates, the external metallic components are coated with a protective layer of vaseline to prevent corrosion. This protective layer must be thoroughly removed before placing the device into active service.

Technical Summary

The 16LO2I is a dual-gun, electrostatically focused and deflected cathode-ray tube featuring a green-emitting screen with a medium persistence of ≤ 0.1 s. Operating with a nominal 6.3 V heater, it requires a multi-anode supply configuration (typically 350–650 V on the first anode, 2000 V on the second, and 3500 V on the third) to achieve a sharp, focused line width of ≤ 0.8 mm. Its independent dual-beam architecture, robust mechanical and environmental tolerances, and specific installation requirements make it a highly capable display component for demanding visual registration and oscillographic applications.