video distribution amplifier

elektor july/august 1985 I video distribution amplifier To feed a number of high-resolution monitors from one source (computer, video recorder), an amplifier is required that, apart from a reasonable gain, has a wide bandwidth. Unfortu- nately, these two requirements are not completely compatible, but the design presented here offers a fair com- promise. The circuit is capable of driving five 75 Q loads simultaneously: the band- width at each of the outputs is 30 MHz. It consists of a differential amplifier, T1-T2, which is followed by afastemitterfollowerformedbyT4 and T 5. The gain of the differential amplifier is about 23 dB. Transistors 1 3 and T6 are current sources of 30 mA and 200 mA respectively. Feedback network R7-R6-R5-C3-C4 ensures a bandwidth of around 50 MHz and a level pass band. Capacitor C 5 stabilizes the amplifier in the high-frequency region. When all five outputs are loaded, the bandwidth reduces to about 30 MHz, and the pass band then shows vari- ations of ar...