Mischschaltung fuer Dezimeter- und Zentimeterwellen

665,285. Electron beam valves. PHILIPS ELECTRICAL, Ltd. Jan. 7, 1949 [Jan. 12, 1948], No. 510/49. Class 39 (i). [Also in Groups XL (b) and XL (c)] An electron-beam tube utilized as the local oscillator in a high-frequency radio receiver (see Group XL (c)), and which provides a succession of sharply-peaked voltage pulses comprises a cathode 22 giving a beam of electrons which is deflected to form a conical surface by means of high-frequency oscillations applied to a system of deflector electrodes 23. The beam strikes a collector electrode 24 of helical shape, Fig. 5 (not shown), so disposed that electrons leaving the cathode at different moments arrive simultaneously; the tube may also include a grid 25 similar in shape to the electrode 24, the output being taken from the electrodes 24, 25 over a concentric cable 15. The electrode 24 may alternatively be plane.