Standard Horizon Matrix GX3000E, Руководство по обслуживанию

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swallow counter, programmable counter, a serial data in-
put port to set these counters based on the external data,
a phase comparator, and a charge pump.
The PLL synthesizer IC divides the 29.950 MHz reference
signal by 2396 using the reference counter (12.5 kHz com-
parison frequency). The reference oscillator feeds to the
PLL synthesizer IC
Q1034 ( TB31202FNG ) for the 2nd lo-
cal signal.
The VCO output is divided by the prescaler, swallow
counter and programmable counter. These two signals are
compared by the phase comparator, and applied to the
charge pump.
A voltage proportional to their phase difference is deliv-
ered to the low-pass filter circuit, then fed back to the VCO
as a voltage with phase error, controlling and stabilizing
the oscillating frequency.
The TX & SUB VCO is consisted of Q1031 ( 2SK520-K41 )
and varactor diode D1014 , D1015 , D1016 , and D1017 (all
1SV286 ), which oscillates at 134.225 MHz. The TX & SUB
VCO output passes through buffer amplifier Q1028
( 2SC5006 ) to obtain stable output.
1050 Hz Weather Alert Decoder
1050 Hz Weather Alert signal from the FM IF subsystem
IC
Q1049 ( TA31136FN ) on the RF Unit is demodulated
by Q2007 (
2SC4154E
) on the AF Unit, then is applied to
16-bit MPU IC Q3004 ( M30626FHPGP ) on the CNTL Unit.
PA (Public Address) Circuit
A voice audio from the microphone is delivered to the AF
Unit. A voice audio is amplified by
Q2020 ( LM2902PW ),
t h e n p a s s e s t h e A F / M I C s e l e c t s w i t c h Q 2 0 1 3
( C D 4 0 5 3 B P W ) t o t h e b u f f e r a m p l i f i e r Q 2 0 2 3
(LM2902PW). The audio then passes through the LB/HAIL
select switch
Q2011 ( BU4066BCFV ) and MUTE switch
Q2012 (
CD4066BPW
) to the buffer amplifier Q2018
( NJM2904V ). The amplified audio is passed through the
LB/HAIL select switch Q2011 (
BU4066BCFV
) and buffer
amplifier Q2023 ( NJM2902PW ) to the electronic volume
control IC Q2017 (
M62421FP
) for volume control. The
adjusted audio is delivered to the audio power amplifier
Q2014 (
TA8225H
) which is amplified the voice audio up
to 30 watts, and then passes through the relay switch
RL2001 to the external PA speaker.
Circuit Description
LB (Listen Back) Circuit
The listen back audio from the PA speaker is delivered to
the AF Unit. The audio is passed through the relay switch
RL2001 and buffer amplifier
Q2023 ( LM2902PW ) to the
LB/HAIL selector switch Q2011 ( CD4033BPW ), then pass-
es through the MUTE switch Q2012 ( CD4066BPW ) to the
buffer amplifier Q2018 ( LM2902PW ). The audio then
passes through the AF/MIC select switch Q2013
( CD4053BPW ) to the electronic volume control IC Q2017
( M62421FP ) for volume control. The adjusted audio is
delivered to the audio power amplifier Q2019 ( LA4425A )
which is amplified the voice audio up to 4.5 watts, and
then deliver to the internal or external speaker.
A portion of the audio from the Q2012 ( CD4066BPW ) is
passed through the buffer amplifier Q2018 ( LM2902PW )
and AF/MIC select switch Q2013 ( CD4053BPW ) to the
RAM microphones, if connected.
Fog Horn Circuit
A 400 Hz square wave for foghorn is generated by the mi-
croprocessor
Q3004 ( M30624FHPGA ) on the CNTL Unit,
then deliver to the AF Unit. A 400 Hz square wave passes
through the buffer amplifier
Q2023 ( LM2902PW ) to the
electronic volume control IC Q2017 (
M62421FP
) for vol-
ume control. The adjusted audio is delivered to the audio
power amplifier
Q2014 ( TA8225H ) which is amplified the
voice audio up to 30 watts, and then passes through the
relay switch RL2001 to the external PA speaker.
MPU
Operation is controlled by 16-bit MPU IC Q3004
(
M30626FHPGP
) on the CNTL Unit. The system clock
uses a 14.74560 MHz crystal X3001 for a time base. IC
Q3003 (
PST597CN
) resets the MPU when the power is
on, and monitors the voltage of the regulated 5V power
supply line.
EEPROM
The EE-PROM Q3006 ( AT24C128N ) on the CNTL Unit
retains TX and RX data for all memory channels, prescal-
er dividing, IF frequency, local oscillator injection side,
and reference oscillator data.