Accession Number : AD0663167

Title :   DEVELOPMENT OF LINEAR POWER TUBES.

Descriptive Note : Interim development rept. 17 Aug-16 Nov 67,

Corporate Author : EIMAC SAN CARLOS CALIF

Personal Author(s) : Sain,William H. ; Liljegren,Gordon E.

Report Date : 15 DEC 1967

Pagination or Media Count : 57

Abstract : Tests were performed on the modified 4CX5000 (X552) and the modified 4CX3000 (X784) as well as on the EIMAC standard production 4CX5000R and the 5CX3000A. A 5000 watt tetrode with auxiliary electrode (X552-P), a 5000 watt pentode with auxiliary electrode (X552-R), and a 3000 watt pentode with auxiliary electrode (X784-N) were tested using a variety of DC auxiliary electrode voltages as well as combinations of DC suppressor voltages. The results of tests indicate that a DC voltage on the auxiliary electrode will cause a change in the intermodulation distortion characteristics. The pentode models with auxiliary electrodes gave the most encouraging results. From zero to 4500 watts PEP, a third order intermodulation distortion of -45 db and a fifth order intermodulation distortion of -50 db can be expected. However, at 5000 watts PEP the distortion becomes worse. When a saturated (non-linear) RF drive voltage is applied to the auxiliary electrode in phase with the grid drive voltage, the distortion at optimum operating conditions is -50 db from zero to 5000 watts PEP. Attempts were made to use other methods in tube design to improve linearity. The EIMAC 5CX3000A (standard production) was tested and gave satisfactory results; however, at the 5000 watt PEP level, the fifth order intermodulation distortion level does not meet the proposed -50 db goal. An experimental pentode of the 5000 watt type was built. The test results indicate -45 db third order and -50 db fifth order intermodulation distortion from zero to 5000 watts PEP. An increased range of operating parameters (over the 5CX3000A) is available with the 5000 watt pentode. (Author)

Descriptors :   (*BEAM POWER TUBES, LINEAR SYSTEMS), TETRODES, PENTODES, MODULATION, DISTORTION, CATHODES(ELECTRON TUBES), RADIOFREQUENCY POWER

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE