SRG-1150DN / SRG-1250DN / SN-100
a) MICRO COMPUTER be set by operating PANEL and set synchronizing circuit
responded by receiving frequency (selecting channel).
And then, according to receiving frequency, set information setting frequency for
SYNTHESIZER or REF/BFO.
In addition, MICRO COMPUTER pass signal (LOCAL CONTROL) to indic ate various
information(receiving frequency, receiving mode, band, width) set by operating
panel of controller unit and transmit in control unit.
Except this function, in case of interception of power or supply- cease, MICRO
COMPUTER control memory degaussing to be back- up by battery built.
Memory status before normal of power and in case of normal, possible to rebuild.
10.11 FRONT (T-568)
This PCB circuit is composed of switch, LED, voice, sensitivity modulator.
10.12 W/K RECEIVER UNIT(T-552)
Receiving method is 1st intermediate frequency(49.455MHz), DOUBLE- SUPER
HETERODYNE TYPE of 2nd intermediate frequency(455KHz).
All local signal of receiver is supplied from DIGITAL CONTROL F R E QUE NC Y
SYNTHESIZER through PHASE LOCKED LOOP(PLL) system and direct system to
use 10MHz center oscillator(supplied from DTCXO : SSB GENERATOR circuit).
a) Receiving signal in ANTENNA terminal pass BK RELAY and input and voltage
protecting circuit and pass band- pass filter and is closing in DSC distress safety
frequency.
FILTER is separated from inner MICRO COMPUTER to response in receiving
CHANNEL.
b) Receiving signal to pass filter passes 35MHz low band passing- filter and amplify
by high- frequency amplifier of width band and is supplied in first mixture part.
First mixture part is balance type of gate earth and receiving signal is
converted to 49.455MHz of 1st intermediate frequency to mix with 1 signal
supplied from 49.455MHz to 79.45499MHz from SYNTHESIZER Converting output
pass CRYSTAL FILTER of center frequency 49MHz passing band about 15KHz
and amplify through 1st intermediate amplifier and is supplied in 2 mixture part.
Receiving signal as 2 mixture part is mixed with 2 signal supplied from