User's Manual
Charge Pump and Loop Filter
Transistors Q2,Q4,Q10 , and associated resistors and capacitors form the charge pump and loop
Filter . The phase detector output from IC1 pins 15 and 16 are combined by the charge pump to
Produce a 0 to 8V tuning voltage signal.
The signal is filtered by the loop filter (R13,C15 and C20) to remove any residual reference
Frequency harmonics from the signal.. After filtering the signal is applied to the voltage controlled
Oscillator module.
DC REGULATOR
The DC Regulator IC2, converts the +13.6 V to a 8V supply . This is used to provide the
Tuning voltage for the VCO . A wide voltage range is required to allow for the wideband operation
Of the radio .
Dual modulus prescaler
The prescaler divides the VCO frequency by 64 or 65.
Transmitter
The transmitter comprises:
VCO Buffer PA Module
Amp
PAGE7
RF LPF
ANTENNA
SWITCH
Automatic
Power Control