From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Letter to the General Electric Co. regarding the supply and potential modification of a U.3. Rectifying Valve.
| Identifier | ExFiles\Box 41\2\ Scan073 | |
| Date | 19th March 1930 | |
| X3646 EFC2/MS. 19th. March 1930 The General Electric Co. Magnet House, Moor Street, Birmingham. Dear Sirs, U.3. Rectifying Valve. May we recall with you our correspondence with reference to a U.3. rectifying valve which we have been using. The reference of your last letter is W & V/HB{C. E. Harcombe}/466 of Oct.24th.1927. at which time you supplied us with a second valve of this type. This second valve has been in satisfactory intermittent service until 14.3.30. when failure occurred due to excessive bowing of the filament under electro static stress. We are quite aware that we are using the valve for pressures above which you rate it, but the valve is so suitable in other ways and a larger one would be so inconvenient in our apparatus, that we propose to continue to use this type of valve for the purpose in hand. In our estimation all that is required to increase the life of this valve on H.T. rectification for H.T.D.C. testing, is a support for the middle of the filament. We are anxious to know if:- (1) You still supply this type of Valve. (2) You would be prepared at some slight extra cost to favour us by making a special one, the same in external arrangement, but with one or both of two internal modifications viz. (a) Larger diameter anode. (b) Improved mechanical support to filament. contd. | ||