This circuit has an automatic dynamic gain control in a range of 6 dB to 40 dB. We found it in documentation from the 90s. The bipolar transistor is a general purpose type.
This circuit was published in a January 1971 issue of Radio Electronics to check television...
Found in Popular Electronics from the 90's, this tuned to infrared modulated receiver uses a PLL....
This 1967 General Electric circuit makes use of an array of 3 (integrated) transistors for an...