SRG-1150DN / SRG-1250DN / SN-100
Mixed signal is divided to 3 species as follows.
① amplify for inner speaker audio.
② amplify for outer speaker audio.
③ FSK MODEM (DSC signal mix)
10.5 MOTHER BOARD(T-570)
Function of Mother Board (T- 570) is connecting PCB
T- 451(SRG- 1150DN TX FILTER)/ T- 461(SRG- 1250DN TX FILTER),
T- 454(TX/RX EXCITER),
T- 557(CONTROL), T- 553(PLL SYNTHESIZE),
T- 555(POWER SUPPLY UNIT),
T- 552(W/K RECEIVER),
T- 514(SRG- 1150DN TX POWER AMP)/T- 524(SRG- 1250DN TX POWER AMP)
each other.
BK signal given from external pass PHOTO COUPLER to separate union earthing
POLE from receiver inner circuit and supply in BK control circuit.
BK controling circuit control BK RELAY of input unit of high frequency and AGC
circuit and protect receiver from over input.
Simultaneously, have a muting receiving circuit.
Moreover, it connect several connectors at rear side and do switching power
supply of RX and TX.
a) This circuit board incorporate through most circuit board to consist
of main unit organically and electronically and operate.
b) In this circuit board, connecting of front, real and external is carried on
and each connector pass filter circuit for noise- clear and is connected
c) Each circuit board connected by this circuit board arranged connectors
mechanically not to incorporate in wrong- position.
SCHEMATIC IS AS FOLLOW.