Service Manual VHF (136-174MHz) Information
401
There are two types of VCO: TX VCO and RX VCO. Both types control EMD22 to switch operating
status via OMAP. RX VCO is composed of the oscillator loop and Q104, to provide LO signal. TX VCO
is composed of the oscillator loop and Q108, to provide carrier for TX signal.
11.3.3 Direct Modulation
In TX mode, direct modulation will be applied because of low VHF frequency. MOD-VCO and
MOD-XO send modulation signal to VCO and PLL respectively to modulate TX VCO and PLL.
To Next Page
Loading...
