Method of making electronic tube grid

Claim 1

A METHOD OF MAKING AN ELECTRONIC TUBE GRID HAVING UNIFORM AND EXTREMELY SMOOTH TUNGSTEN WIRES SECURED TAUT ACROSS AN APERTURE IN A TUNGESTEN FRAME WHERE THE WIRE CORSS SECTION IS SMALLER THAN CAN BE OBTAINED BY WIRE DRAWING METHODS WITHOUT CONSIDERABLE BREAKAGE LOSS AND WHERE ETCHING FOLLOWING WIRE DRAWING TO REDUCE THE DRAWN WIRE CROSS SECTION TO SAID SMALL CROSS SECTION RENDERS THE WIRE TOO BRITTLE TO HANDLE, WHICH COMPRIESES: POSITIONING ACROSS THE FRAME APERTURE STRETCHES OF TUNGSTEN WIRE OF SUBSTANTIALLY UNIFORM COMPOSITION THROUGHOUT AND OF A CROSS SECTIONAL SIZE LARGER THAN SAID GRID WIRE SIZE AND IN A DESIRED PATTERN, TENSIONING THE WIRES TO A TENSILE STRESS APPROACHING THE BREAKING POINT WHEN COLD, AND THEN BRAZING THE TENSIONED WIRE ENDS TO SAID FRAME OUTSIDE SAID APERTURE IN GOOD ELECTRICAL CONTACT WITH THE FRAME WHEREBY THE SECURED WIRES ARE UNDER TENSILE STRESS APPROACHING THE BREAKING POINT WHEN COLD, THEN MASKING THE ENDS OF SUCH STRETCHES WHERE SECURED TO SAID FRAME WITH A MATERIAL THAT IS SUBSTANTIALLY INERT IN A 0.4% SODIUM HYDROXIDE SOLUTION TO WHICH ENOUGH AMMONIUM CHLORIDE IS ADDED TO LOWER THE PH TO 10, THEN IMMERSING THE GRID AND A PLATINUM CATHODE IN SAID SOLUTION, APPLYING 5-7 VOLTS DIRECT CURRENT BETWEEN SAID GRID AND SAID PLATINUM CATHODE FOR A PERIOD OF TIME SUFFICIENT TO REDUCE THE WIRE CROSS SECTION TO SAID GRID WIRE SIZE, REMOVING THE GRID FROM THE ETCHING SOLUTION AND WASHING THE DRYING THE GRID.