| 摘要 |
A transceiver, adapted for use as either a master or a slave in a duplex pair, has a single, voltage-tunable, solid state oscillator to provide the carrier frequency wave, a small portion of which is mixed with the received wave and applied therewith to a single ended mixer; an AGC-controlled loop cancels transmitter input modulation from the receiver output. The oscillator of the master transceiver is locked to a desired carrier frequency by a feedback loop including a tuning cavity adjusted to a frequency different from that of the slave transceiver by the common IF frequency; the slave transceiver is first locked to the frequency of its tuning cavity and thereafter, upon sensing output from its IF amplifier (from the master), is switched to operate in response to AFC controlled by the received signal, such that the master and slave transceivers are locked together at frequencies differing by their common IF frequency. A single integrating amplifier provides demodulator and AFC filtering and, together with a bistable device, initial sweeping of the oscillator control voltage. |
