Figure 8-5 Diagram Of Vco - Hytera MD78X Service Manual

Service Manual UHF1 (400-470MHz 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 8-5 Diagram of VCO

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