Hawes Mechanical Television Archive by James T. Hawes, AA9DT
Schematic Symbol Key

Rb1 & Rb2 Base-bias resistors
Rc Collector resistor
Re Emitter resistor
Q1 The transistor: The schematic shows an NPN-type transistor.
Ce Emitter bypass capacitor: Normally, Ce would be an electrolytic capacitor. If you use an NPN transistor, connect the capacitor's positive side to the Q1 emitter.
Vcc Power bus: With an NPN transistor, this top bus connects to the positive lead of the power supply or battery.

NOTES: The remaining or bottom bus is common. With an NPN transistor, this bottom bus connects to the ground lead of the power supply or battery. You can use a PNP transistor in this circuit. To use a PNP transistor, reverse the ground and Vcc buses and reverse Ce polarity.

APPLICATIONS. You can use this circuit to amplify audio or mechanical TV signals. Capacitor Ce determines the amplifier's lowest frequency. For mechanical television, this frequency should be only a few Hz. Otherwise, distortion will replace large picture details. The calculator makes Ce large enough to accept the lowest mechanical television frequencies. These frequencies are subaudible. The resulting amplifier could also reproduce the bottom notes of an organ.

            drawing of amplifier this calculator designs


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