. The Bell System technical journal . If the rise time is improved by in-creasing the trigger current, the gain is decreased. The principal causeof the poor gain-bandwidth appears to be the depletion layer capaci-tance.^^ The difficulty can be overcome by selecting a point contacttransistor. A particular germanium transistor coded GA-52996* appearsto be suitable and has the following pertinent characteristics: a. Collector capacitance less than uuf, b. Alpha cut-off frequency in excess of 80 mc, c. Base resistance less than 100 ohms. Since the alpha of this unit is greater than 2 at collec
. The Bell System technical journal . If the rise time is improved by in-creasing the trigger current, the gain is decreased. The principal causeof the poor gain-bandwidth appears to be the depletion layer capaci-tance.^^ The difficulty can be overcome by selecting a point contacttransistor. A particular germanium transistor coded GA-52996* appearsto be suitable and has the following pertinent characteristics: a. Collector capacitance less than uuf, b. Alpha cut-off frequency in excess of 80 mc, c. Base resistance less than 100 ohms. Since the alpha of this unit is greater than 2 at collector currents ofthe order of 10 ma, the common base connection will yield the greatestcurrent gain. The disadvantage of a point contact unit, of course, is theIco current. For this reason the amplifier will have to be designed to usethe smallest possible collector supply voltage. The point contact transistor, due to its high cut-off frequency relativeto the amplifier pulse repetition rate and its high alpha at small emitter T~L INPUT. I -8V II +6V 3VOLT PEAK iI MEGACYCLE SINE WAVE VOLTAGE
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