Yaesu VX-120 Technical Supplement page 8

Circuit Description
erence frequencies, which are utilized by the phase com-
parator.
The phase comparator section of Q1003 (MB15A01PFV1)
compares the phase between the frequency-divided os-
cillation frequency of the VCO circuit and comparative
frequency and its output is a pulse corresponding to the
phase difference. This pulse is integrated by the charge
pump and loop filter of D1012 (DA221) and Q1016
(DTC144EE) into a control voltage (VCV) to control the
oscillation frequency of the VCO.