HYT TC-700 Ex PLUS, Руководство по обслуживанию

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TC-700 EX PLUS Service Manual
15
Circuit Description
1. Power Supply
The radio is supplied by the battery. The power supply is from B+, and supplies power SWB+ for the
three AVRs, after passing through fuse FE250mA and switch. IC504 supplies 5V (M5V) voltage for the
control circuit. And IC503 supplies 5V (C5V) voltage for the shared circuit. IC502 supplies voltage for the
transmit/receive circuit. While transmitting, T5C becomes low level and Q502 is turned on to supply 5V
(T5V) voltage for the transmit circuit. While receiving, R5C becomes low level and Q504 is turned on to
supply 5V (R5V) voltage for the receive circuit. Power supply for RF is from B+ and works after passing
through fuse FE4 2A. Power supply for audio PA is from B+ and works after passing through fuse FE5
0.5A.
Fig. 1 Power Supply Block Diagram
2. PLL Frequency Synthesizer
PLL circuit generates the first local oscillator signal for receive and RF signal for transmit.
AVR
AVR
AVR
SW
FUSE
BATT
SW
T5C
T5V
SW
R5C
R5V
5CNS
C5V
M5V
SAVE