Figure 10-5 Diagram Of Vco - Hytera MD78X Service Manual

Service Manual UHF2 (450-520MHz 25W) Information
oscillators. There are four VCOs in all: two VCOs (Q100 and Q103) used to transmit excitation signals
and the other two VCOs (Q106 and Q110) to receive LO signals. U302 controls the operating
frequency of the VCO. Q102 and Q107 constitute the buffer amplifiers for the transmitter circuit, while
Q111 and Q109 for the receiver circuit. The digital-to-analog converter (U500) modulates the TX
oscillator signal.

Figure 10-5 Diagram of VCO

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