User's Manual

RX is composed of front-end, mixer, local drive, and crystal filter. IF amplifier, IF IC and Data conduct.

MPU is composed of EEPROM storing parameter of controls in the SD-5200.

2. Transmit

2.1 SYNTHESIZER

Synthesizer is consisting of TCXO, PLL IC, Charge Pump, LPF and VCO. See illustration 2-1.

TCXO (U17) plays a key role to make usable frequency for terminal and uses a 14.4MHz(-30? C~ +60? C, 2.5ppm) of

VX-23VA in JVC co. It uses resistance R65, R66 and VR13 externally for accuracy of frequency and modulation of low

frequency data signal. When VR13 is turned to '+', voltage increases and frequency lowers. When VR13 is turned to '-',

frequency rises.

If TX or RX frequency deviation occurs, you can control with VR13.

Inside of PLL IC, there are 4 Divider Registers (CH1, CH2 Programmable Divider, Reference Divider and Option Control).

Now, SD-2000N/5200 use only CH1 Programmable Divider

2.1.1 Composition of Divider Register

Inside of PLL IC consistsof 4 Registers and is set with code.

14.4MHz

TCXO

U104

Reference

Counter

Loop

Filter

VCO

Prescaler

Counter

Phase

Detector

Counter

Illustration 2-1 Composition of Synthesizer