(No.RA033<Rev.001>)1-25
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Modulation circuit (Analog/Digital signal processing)
In the case of the Analog Signal Processing mode, the transmitting audio signal is amplified by IC252, input to the TX_MIC terminal
of the MPU (IC200), and audio processed by DSP (IC150).
The processed audio signal from the MOD terminal of IC200 is passed through an anti-aliasing filter at IC250, and is then amplified
to a sufficient level by IC250, and amplified by the summing (TD) amplifier.
The Digital Signal Processing mode is the same as the Analog Signal Processing mode.
Fig.20 Audio and Squeluch circuit
2.6.5.13 Real-time clock
The clock function is based on a real-time clock IC (IC900) and X900.
When the power supply is off, it is backed up by an internal secondary lithium battery.
2.6.5.14 Display Circuit
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Display circuit
The display circuit consists of various types of LEDs, 17-segment type D951 and D952, 8-bit status LEDs D925 to D932, and LEDs
with built in switches S920 to S925.
LED for status display of a Power, TX, Busy, CTRL and OCXO is D901 to D910.
IC951 and IC952 are in charge of displaying present channels.
IC904 and IC907 are shift registers that convert the MPU serial data to parallel data and turn on LEDs.
•
Key switches circuit
The logic signals from the front panel key and channel switches (channel selector) are entered directly into the MPU (IC200).
2.7
COMPONENTS DESCRIPTION
2.7.1 FINAL UNIT (XC3-0150-10)
MPU
IC200
DSP
IC150
SqueluchDAC
IC452
EVOL
IC259
MOD
RXAF
BEEP
RA
Power AMP
IC533
SPM
/AF_MUTE
TD
TD_SW
RD
TD
TD
Vi8
TA
SW
VREF
IC251 1/2
SW
SW
IC532
Q532
MIC
IC450 1/2
SPO
IC252
2/2
IC250
1/2
2nd order L.P.F
AMP
IC250
2/2
IC252
1/2
IC257
1/2
IC258
2/2
IC258
1/2
IC255
1/2
Vo1
Vi1
Vi3
Vo3
Vi4
Vo4
IC531
Q533
IC255
2/2
Vo8
IC254
VREF
1/2_33A
IC257 2/2
SW
2nd order
L.P.F
6dB
Inverter AMP
Common
emitter AMP
Rectifire
Mute
R-network
Buffer AMP
IC451 1/2
IC450 2/2
Q450
RX_UL from RX UNIT
VREF
Buffer
IC251 2/2
2nd Order L.P.F
Invrter AMP
Invrter AMP
TX_MIC
TX_TA
AMP
SUM AMP
IC908
AMP
AMP
AGC
Q909,Q910
Ref. No.
Part Name
Description
IC1, 2
IC
DC amplifier
IC3
IC
AVR
IC4, 5
IC
DC amplifier
IC10
IC
RF amplifier
IC11
IC
AVR
IC250
IC
Switching
IC400
IC
DC amplifier
IC450
IC
Temperature sensor
IC451
IC
DC amplifier
IC500
IC
E2PROM
IC501
IC
Temperature sensor
IC550
IC
AVR
Q2
FET
Switching
Q4, 5
FET
Switching
Q18
FET
Switching
Q251
FET
Switching
Q450, 451
FET
Switching
Ref. No.
Part Name
Description
Summary of Contents for NXR-5700
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