Abstract: A split collector lateral transistor wherein the amount of the emitter encircled by each of the collectors is unequal so that a greater current flows in one of the collectors and the base current plus the current flowing in the other collector is approximately equal to the greater current flowing in the one collector.

Abstract: An oscillator with a ceramic resonator in the feedback circuit for providing a stable continuous signal to a programmable divider each time an enable signal is applied to the oscillator, a read-only memory connected to the programmable divider and operated by timing means, including a counter and a clock, which sequentially switches the memory to cause the programmable divider to divide the output of the oscillator by a different divisor to provide a predetermined sequence of signals, each having a desired frequency.

Abstract: A combined encoder-decoder for use in two-way radio systems. The apparatus is operable in an encoder mode to provide tone oscillations during operation of the radio apparatus in the transmit mode and also in a decoder mode to provide a control signal in response to a received tone signal of a particular frequency during operation of the radio apparatus in the receive mode. The encoder-decoder includes a single active filter and a feedback circuit selectively coupled to the filter to form an oscillator for producing the tone oscillations in the encoder mode of operation. An input amplifier/limiter is enabled to apply received tone signals to the active filter during decoder operation. A control circuit responsive to operation of the radio apparatus is coupled to the feedback circuit and to the input circuit so as to selectively enable the feedback circuit during encoder operation and the input circuit during decoder operation.