| 摘要 |
A transceiver channel selection circuit operable in both transmit and receive modes of operation including a digital phase lock circuit having a controllable oscillator, a reference frequency source, and means for obtaining a signal, the frequency of which is an aliquot part of the controllable oscillator frequency, are connected together in a feedback loop and the reference frequency and submultiple frequency compared and the controllable oscillator frequency changed, if the submultiple and reference frequencies differ. The particular submultiple or aliquot portion of the controllable oscillator frequency is determined by a manually operable selector switch, the state of which programs counters to count up to value determined by the particular switch state and the particular submultiple is different in the receive and transmit modes on a particular selected channel with this difference being a first fixed value for simplex channels and a second fixed value for duplex channels, with the simplex or duplex mode of operation being at least in part determined by the particular channel selected. The channel selector switch includes receive only channel positions and provides a transmitter lock-out signal for those channels and certain switch contacts may provide for direct energization of an illuminated channel indicated display arrangement.
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