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Circuit Description
The 5 Watts RF signal passes through high-pass filter and
high-pass filter network, antenna switch D1044 (RLS135),
and another low-pass filter network, and then deliver to
the ANT jack.
TX APC Circuit
A portion of the Power amplifier output is rectified by
D1051 (UHF: D1046 and D1047) (all RB751S), then de-
livered to APC Q1054 (TA75S01F), as a DC voltage which
is proportional to the output level of the power amplifier.
The APC Q1054 (TA75S01F) is compared the rectified DC
voltage from the power amplifier and the reference volt-
age from the main CPU Q1031 (HD64F2266), to produce
a control voltage, which regulates supply voltage to the
Drive amplifier Q1074 (2SK2596) and Power amplifier
Q1075 (RD07MVS1), so as to maintain stable output power
under varying antenna loading condition.
8
PLL
A portion of the output from the VCO Q1065 (UHF:
2SC5006) and Q1067 (VHF: 2SC5006), passes through
buffer amplifier Q1066 (UHF), Q1068 (VHF), and Q1040
(all 2SC5006) programmable divider section of the PLL
IC Q1037 (MB15A01PFV1), which divided according to
the frequency dividing data that is associated with the set-
ting frequency input from the main CPU Q1031
(HD64F2266). It is then sent to the phase comparator.
The 11.7 MHz frequency of the reference oscillator circuit
made up of X1002 is divided by the reference frequency
divider section of Q1037 (MB15A01PFV1) into 2340 or
1872 parts to become 5 kHz or 6.25 kHz comparative ref-
erence frequencies, which are utilized by the phase com-
parator.
The phase comparator section of Q1037 (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 Q1037 (MB15A01PFV1) into a
control voltage (VCV) to control the oscillation frequency
of the VCOs.
FT-60R/E Technical Supplement
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