Two simple types of feedback amplifier for the relaying of television signals over coaxial cables

A method is described for applying loop negative feedback to flatten the gain/frequency characteristics of three-stage amplifiers employing tuned-anode intervalve couplings resonant at the geometrical mid-band frequency of the pass-band. A comparison is made with the responses of amplifiers employing different types of intervalve couplings. Apart from the well-known advantages of negative feedback, the performances of the amplifiers described should be superior to those of the other amplifiers, since they are simpler and easier to align. Two typical feedback amplifiers, using this design method, are described. They are employed for the transmission of television signals over coaxial cables. The possibility of feedback amplifiers operating as regenerative modulators at high levels of signal is discussed.