Microminiature high-frequency transmitter-receiver
01 January 1967
A mobile radio transmitter-receiver is described that operates between 2 and 30 MHz for voice modulation with either single sideband, or carrier and double sideband. The basic unit produces 7 watts for transmission. A 4 MHz oscillation is controlled by a temperature stabilised quartz crystal. This signal is multiplied and divided to produce 28 MHz and 1 MHz for heterodyning and 10 kHz as a reference frequency. I.c. oscillators produce any desired frequency between 11 and 35 MHz and are stabilized through a frequency divider referenced to the 10 kHz signal. Varactors are used to tune a single set of circuits that couple the antenna to either the transmitter or receiver, and are also used to tune the controlled oscillators.