Streamlined Modulators for Transistor Transmitters

Presented here are two unusual methods of modulating transistor transmitters that rival the commonly used transformer coupled collector modulation technique in performance. While neither circuit is really new (they both have basic vacuum tube histories), the implementation to transistor circuitry is unique* Both of ihe techniques discussed streamline the modulator by eliminating the bulky modulation transformer and its attendant matching problems. Hence, the primary advantages of reduced size, weight, and power consumption gain by utilizing transistors are further enhanced by streamlining the modulation amplifier,

DC-series modulation fhe compact, high quality modulation technique shown in Fig, 1, is termed dc-series modulation because the modulating transistor is in series with the final dc supply voltage. In this circuit, the modulating transistor is shown in the emitter leg; however, it is effectively varying the collector supply voltage. The emitter is used because proper voltage polarities are available for coupling the low cost pnp germanium audio transistor to the in

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