| 释义 |
pentagrid Electronics.|ˈpɛntəgrɪd|
[f. penta- + grid.]
A thermionic valve having five grids; a heptode. Freq. attrib. or as adj.
1933Wireless World 12 May 347/1 The Pentagrid Converter..has been recently developed in America. Ibid. 347/3 With the Pentagrid..the necessary coupling occurs within the valve and, by virtue of the screening, is entirely electronic in nature. 1950P. Parker Electronics xiv. 549 Occasionally a frequency-changing valve..has a suppressor grid; it is then called a heptode or pentagrid. 1953A. H. W. Beck Thermionic Valves x. 308 In the pentagrid mixer, the local oscillation is generated by a separate valve. 1966H. J. Reich et al. Theory & Applications Active Devices vii. 165 Another useful tube structure is the five-grid or pentagrid tube, in which the five grids of helical construction are mounted between the cathode and the plate. This tube affords considerable flexibility in design of certain electronic circuits. Perhaps the most frequent application..has been in the mixer-oscillator section of radio receivers. |