Complementary frame grid pentodes for two-stage TV IF applications

The trend in television receiver design continues to be toward reducing the tube complement while maintaining or surpassing present quality levels of reception. The use of higher gain tubes in video IF stages can result in two-stage IF performance approaching that obtained with three stages of IF amplification. Types 6JK6 and 6JL6 are complementary miniature T-5^½ pentodes designed primarily for two-stage IF applications. The 6JL6 is a semi-remote cutoff tube for the gain controlled stage(s), while the 6JK6 is a sharp cutoff tube for the fixed gain stage. Both types utilize frame-grid construction giving a more efficient tube with vastly improved Gm. This paper discusses the characteristics of these new tube types and the design and performance of a two-stage IF amplifier.