METZ 7273 HAITI COLOR CHASSIS 680G CRT VALVO EURO COLOR (PHILIPS) A51-590X/3520)

 

 

 

 

 

 Hi-bri COLOUR PICTURE TUBE

•90° deflection
•In-line gun, thermally stable; electrostatic hi-bi potential for improved focus


• 29, 1 mm neck diameter
• Hi-Bri screen with pigmented phosphors featuring high brightness and increased contrast performance
• Soft-Flash technology offering improved set reliability
• Slotted shadow mask optimized for minimum moire
• Fine pitch over entire screen
• Phosphor lines follow glass contour
• Quick-heating cathodes
• Internal magnetic shield
• Reinforced envelope for push-through mounting
• When combined with an appropriate hybrid saddle toroidal deflection unit (e.g. AT1236 or AT1480),
it forms a self-converging and raster correction free assembly.

FLASHOVER PROTECTION
With the high voltage used with this tube (max. 27,5 kV) internal flashovers may occur. As a result of
the Soft-Flash technology these flashover currents are limited to approx. 60 A offering higher set
reliability, optimum circuit protection and component savings.
Primary protective circuitry using properly grounded spark gaps and series isolation resistors (preferably
carbon composition) is still necessary to prevent tube damage. The spark gaps should be connected to
all picture tube electrodes at the socket according to the figure below; they are not required on the
heater pins. No other connections between the outer conductive coating and the chassis are permissible.
The spark gaps should be designed for a breakdown voltage at the focusing electrode (g3) of 11,5 kV
( 1,5 x Vg3 max. at Va,g4 = 25 kV), and at the other electrodes of 1,5 to 2 kV.
The values of the series isolation resistors should be as high as possible (min. 1,5 kn) without causing
deterioration of the circuit performance. The resistors should be able to withstand an instantaneous
surge of 20 kV for the focusing circuit and 12 kV for the remaining circuits without arcing.

 Notes
1. Absolute maximum rating system.
2. The X-ray dose rate remains below the acceptable value of 0,5 mR/h, measured with ionization
chamber when the tube is used within its limiting values.
3. During adjustment on the production line this value is likely to be surpassed considerable. It is
therefore strongly recommended to first make the necessary adjustments for normal operation with-
out picture tube.
4. Operation of the tube at lower voltages impairs the luminance and resolution.
5. The short-term average anode current should be limited by circuitry to 1500 μA.
6. For maximum cathode life and optimum performance, it is recommended that the heater supply be
designed for 6,3 Vat zero beam current.

 

 

 

Valvo Bauelemente GmbH is a Germany based company, specializing in the delevopment, manufacture and marketing of ferrite components for microwave and rf applications. Initially part of the Philips Components group this business has 30 years experience in the design and production of standard and special ferrite devices.

When Philips closed its activity located in Hamburg, Valvo Bauelemente GmbH continues this circulator and isolator business and started 1999 as an independent company, only 100 meters off the former Philips location.

AT ancient times VALVO was an components office of PHILIPS then the converted to the above company was started and the previous closed.