1300Z — Instrument Cathode Ray Tube

The 1300Z is a 13 cm flat-faced, single-gun, spiral post-deflection acceleration (p.d.a.) cathode ray tube designed for medium bandwidth applications. It features electrostatic focus, electrostatic deflection, and deflection blanking. The scan voltages required for this tube are compatible with transistorised deflection circuits. Additionally, the tube can be configured to operate as a mono-accelerator, which provides a larger scanned area.

Screen and Heater Specifications

The 1300Z is available with different phosphor screens to suit specific display requirements. The two primary standard configurations are designated as 1324Z and 1346Z:

Other screens can be supplied to special order.

The tube's heater is designed for indirect heating with the following nominal electrical characteristics:

• Heater Voltage: 6.3 V
• Heater Current: 0.3 A

Physical Dimensions, Mounting, and Base Connections

The 1300Z has a nominal face diameter of 13 cm with a flat profile, providing a useful screen diameter of 12 cm. The tube has a maximum overall length of 371 mm and weighs approximately 1 kg (tube alone).

Mounting and Shielding

The tube may be mounted in any position. However, it should not be supported by the base alone. The recommended mounting method is to hold the tube in a suitable rubber mask at the screen and secure it with a clamp around the magnetic shield near the base. The socket should have sufficient freedom of movement to accommodate variations in overall length and base orientation tolerances.

Because the tube is sensitive to magnetic fields, care should be taken not to expose it to strong magnetic fields during either operation or storage. A suitable magnetic shield is recommended for typical installations, and can be obtained from Magnetic Shields Ltd., Headcorn Road, Staplehurst, Tonbridge, Kent.

Base Connections

The tube utilizes a B12F base, supplemented by a side contact and a neck contact, both of the CT8 type. The side contact is connected to the fourth anode ($a_4$), and the neck contact is connected to the geometry correction electrode ($s$).

The pin connections, viewed from the base, are as follows:

Note: If any electrode is not used, it must be connected to the pin shown in brackets (for example, connecting $g_2$ to pin 12).

Electrical Ratings and Capacitances

The absolute maximum and minimum ratings (measured with respect to the cathode unless otherwise specified) are detailed below:

Typical Interelectrode Capacitances

• Cathode to all other electrodes: 4 pF
• Control grid to all other electrodes: 8 pF
• Blanking plate to all other electrodes: 11 pF
• Deflector plates $y_1$ to $y_2$: 1.6 pF
• Deflector plates $y_1$ to all electrodes except $y_2$: 5.0 pF
• Deflector plates $y_2$ to all electrodes except $y_1$: 5.5 pF
• Deflector plates $x_1$ to $x_2$: 2.2 pF
• Deflector plates $x_1$ to all electrodes except $x_2$: 6.2 pF
• Deflector plates $x_2$ to all electrodes except $x_1$: 6.2 pF

Operating Configurations and Typical Performance

The 1300Z can be operated in three distinct configurations depending on the application requirements: two post-deflection acceleration (p.d.a.) modes and a mono-accelerator mode.

Typical Operating Potentials (with respect to cathode)

Mono-accelerator Configuration Details

When operating the 1300Z in the mono-accelerator mode (simple circuit), the two CT8 contacts (side and neck) and pins 5, 9, and 12 must all be connected to each other, unless separate potentials are applied for specific correction requirements. This ties the first anode ($a_1$), third anode ($a_3$), fourth anode ($a_4$), blanking plate ($g_2$), and geometry correction electrode ($s$) to a common 2 kV potential.

Beam Control, Correction, and Distortion Limits

Beam Blanking

The 1300Z features a dedicated blanking electrode ($g_2$). At a beam current of 10 $\mu$A, applying a potential of $+65\text{ V/kV}_{a1}$ with respect to $a_1$ to the blanking electrode will completely cut off the electron beam. This electrode is designed strictly for blanking and must not be used as a brightness control.

Astigmatism and Pattern Correction

• Astigmatism Correction: Adjusting the potential on the third anode ($a_3$) relative to the mean potential of the Y-deflection plates corrects astigmatism. A design adjustment range of $\pm 50\text{ V/kV}_{a3}$ should be provided.
• Pattern Correction: Barrel or pincushion distortion can be minimized by applying an appropriate potential to the geometry correction electrode ($s$) with respect to the mean potential of the X-deflection plates. An adjustment range of $\pm 50\text{ V/kV}_{a3}$ is recommended.

These correction potentials are specified for conditions where the mean potential of the X-plates equals the mean potential of the Y-plates. If a difference between these mean potentials is unavoidable, it should be kept to a minimum. In many applications, these correction potentials may not be necessary.

Distortion and Linearity Limits

When pattern correction is applied, the edges of a test raster are constrained to lie between two concentric rectangles measuring 100 x 60 mm and 97.5 x 58.5 mm. The orthogonal angle between the X and Y deflection axes is maintained at $90^\circ \pm 1^\circ$.

Deflection linearity is tightly controlled: the deflection factor for any deflection of less than 75% of the useful scan will not deviate from the deflection factor at 25% of the scan by more than 2%.

Spot Centering

The minimum scanned area is centered on a point within 3 mm of the physical center of the tube face. Under undeflected conditions, the spot is guaranteed to lie within a 14 mm square at the physical center of the tube face.