Inside Views - Icom IC-725 Service Manual

SECTION 2 INSIDE VIEWS
• PLL UNIT
A/D converter------
(IC12: MB4052M-G)
Cl-V interface-------=
Cl-V diode m a t r i x - - - - -
CPU (IC8: HD63A01YOG83P)
Lithium backup battery---
+5 V regulator-------=
(IC10: TA78005AP)
Sensor c i r c u i t - - - - - -
Band voltage buffer----....;:;;,:..,.,.-""""
(IC9: M54562P)
•MAIN UNIT
Rx bandpass filters
------=-
Rx 1st mixer circuit-----+
Tx 2nd mixer circuit---_...
MCF (Fl1: FL-71)-----,
Noise blanker circuit-----
Rx 2nd/Tx 1st mixer----:
(IC1: ND487C1-3R)
MCF (Fl2:
FL-23)----~====!-i..--I
9 MHz SSB • CW filter
(Fl3: FL-30)
2-1
- - - - - 1 s t LO amp circuit
Phase detector/Prescaler
- - - - - - S u b loop VCO
c - - - - - - - - - D D S UNIT
-:::-------2nd LO circuit
'---------=;----Reference crystal
(X2: CR-21 30.72 MHz)
Divider (IC15: M74ALS74AP)
Space for Ul-7 AM • FM UNIT
+------APC/ALC circuit
' + - - - - - - - -
BFO circuit
;.;------SSB modulator
(IC6: µPC1037HA)
~----Product
detector
(IC5: µPC1037HA)
- - - - R x 2nd IF amplifier
.------9.01 MHz AM filter
(Fl4: FL-116)