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4 - 8
4-5 POWER SUPPLY CIRCUITS
4-5-1 PA UNIT
4-5-2 LOGIC UNIT
4-5-3 MAIN UNIT
LINE
HV
14 V
DESCRIPTION
The voltage from an external power supply
passed through a fuse (F1).
The same voltage as the HV line passed through
the switching relay (RL1).
LINE
8V
T8V
R8V
–5V
PAT8
T13V
R13V
DESCRIPTION
Common 8 V converted from the 14 V line and
regulated by the 8V regulator circuit (IC3005).
8 V for transmitter circuits converted from the 14
V line using TX signal and regulated by the T8V
regulator circuit (IC3005).
8 V for receiver circuits converted from the 14 V
line using RX signal and regulated by the R8V
regulator circuit (IC3005).
Common –5 V converted from the 14 V line and
converted by the –5V DC-DC converter circuit
(IC3501, D3502). The voltage is applied to the
AGC (Q1805, D1803), ALC (IC1701) and AF
selector (IC2102), etc.
8 V for transmitter circuits converted from the 8
V line and regulated by the PAT8 regulator circuit
(IC3005).
13 V for transmitter circuits converted from the
14 V line using TX signal and regulated by the
T13V regulator circuit (Q3801, Q3802). The volt-
age is applied to the TX/RX switching relay (FIL-
TER unit; RL13).
13 V for receiver circuits converted from the 14 V
line using R8V signal and regulated by the R13V
regulator circuit (Q1001, Q1002). The voltage is
applied to the receive 1st mixer circuit
(Q1101–Q1104).
LINE
H5V
5 V
DESCRIPTION
Common 5 V converted from the HV line and
regulated by the H5V regulator circuit (IC5).
Common 5 V converted from the 14 V line and
regulated by the 5V regulator circuit (IC6).
Summary of Contents for IC-718
Page 29: ...SERVICE MANUAL ADDENDUM CONTENTS PARTS LIST 1 BOARD LAYOUTS 19 VOLTAGE DIAGRAM 25 Jun 2011 ...
Page 49: ...Jun 2011 20 C16 CP1 PLL UNIT BOTTOM VIEW FILTER UNIT BOTTOM VIEW PA UNIT BOTTOM VIEW ...
Page 81: ...SERVICE MANUAL ADDENDUM CONTENTS PARTS LIST 1 BOARD LAYOUTS 16 VOLTAGE DIAGRAM 18 Jul 2009 ...
Page 196: ...9 4 VARISTOR BOARD BOTTOM VIEW PLL UNIT BOTTOM VIEW PA UNIT ...
Page 200: ...9 8 BOTTOM VIEW FILTER UNIT ...
Page 206: ...1 1 32 Kamiminami Hirano ku Osaka 547 0003 Japan S 13701MZ C1 q 2000 Icom Inc ...