1、c EIA 179 57 I 3234b00 0028527 4 I - -. *- 4 h ri I m cr: 5 iu cr: RETMA STAND Classification of Tztbe Testers RS=179 February 19S7 Engineering Department RADIQ=ElECTRONICSTElEVISIOPI MANUFACTURERS ASSOCIATION EIA 179 57 W 3234b00 0028528 b W NOTICE RETMA standards are adopted in the public interest
2、 and are designed to eliminate misunder- standings between the manufacturer and the purchaser and to assist the purchaser in selecting and obtaining without delay the proper product for its particular need. Existence of such stand- ards does not in any respect preclude any member or non-member of RE
3、TMA from rrranufacturing or selling products not conforming to the standard. Any proposal of recommended standards and practices made by the Association is without any regard to whether or not their adoption may in any way involve patents on articles, materials or processes. By such action, the Asso
4、ciation does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the recommended standards or practices. Published by ELECTRONIC INDUSTRIES ASSOCIATION Engineering Department 2001 Eye Street, N.W., Waehington, D. C. 20006 Electronic Induatrier
5、 Association 1970 Ail rights reserved PRICE: $1.00 Printed in U.S.A. .- EIA 179 57 3234b00 0028529 8 RS- I 79 Page 1 CLASSIFICATION OF TUBE TESTERS (From Standards Proposal No. 506 formulated under the cognizance of RETMA Engineering Committee G-8 on Test and Mewurement Equipment) Q It shall be stan
6、dard to divide tube testers into four numbered groups as described and illus- trated below. Assignment of any tube tester to one of these groups can readily be made. GROUP I-A device incorporating a circuit in which all available electrodes except cathode are connected together and an AC voltage app
7、lied through a DC indicator between the interconnected electrodes and cathode. GROUP II-A device incorporating a circuit in which separate AC voltages are applied : between grid and cathode; and between other elements, individually or collectively, and cathode. A DC indicator is connected in series
8、with the plate. GROUP applied, current. III-A device incorporating a circuit wherein separate grid signal and bias voltages are with the indicator responsive only to the grid-signal-produced component of the output .- EIA 179 57 = 3234600 0028530 4 W #- CROW IV-A device incorporating a circuit which
9、 permits quantitative measurements of Gm*, 01 Gm and other tube parameters, as defined by ASA C42-1941 (or latest revision). *70.25.045 Transconductance Transconductance from one electrode to another is the quotient of the in-phase component of the alternating current of the second electrode by the alternating voltage of the first electrode, all other electrode voltages being maintained constant. NOTE; As most precisely used, the term refers to infinitesimal amplitudes. i - -I_
