Note on the Stability of Balanced High-Frequency Amplifiers

The question of stability in a balanced or neutralized radio-frequency amplifier is considered for one stage. Experimental and theoretical curves are given for the amplification including regeneration as the plate to control grid capacity is varied in a balanced or neutralized radio-frequency amplifier. The results are discussed for n stages of an impedance coupled amplifier by using the author´s general equation for the limit of stable amplification Av< V/ 2gm/ ncoCe obtained for one stage. The desirability of using a new tube factor Vgm/ Co to compare tubes designed for use in high-frequency amplifiers is also discussed.