Heathkit HD 1418 Schematic

Page 1

T -INPUT OVERLOAD

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L0 W F I LTER

C AUDIO D
AMP

UT
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aw.

U9
Ada-ax

UZZA

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I3

i .
'0 I." run
10 MIG FILTER
->
NOTCH I PEA K n L": R 4 *-_CONTROL VOLTAGES
COMPARATORS INVERTERS- BUFFE R5
(a
25° + , . 7m.
UNA
UZOA @I' a - L
901
_ \ on 3
8h 5.
C45
#01

)_.__-_--..-__________--___.___._.-_.-_.____.____

FILTER SHIFT-

U13
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rm [MINER

: a
U890

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SUPPLY

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HTHG

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ION

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REGULATO R

IO
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a7

77

To "01:! OUR

U1 U4 U 5 U6 U7
3-?! - «2-2: -a -
l4 4 I a if a G
k
I- I I I I E 0
08 U9 U10 U11 U12 U15 U16
' QZEI 42'2l 1-8! Ill-Z! 221 «2-1!
4 $4 $4 $ $4 $4 $
1. I: In In LA
U17 U15 U19 U20 U21 UZZ
442-21 441-. 40-10! 41144 441;"! 234
$¢ $lz 7 7 7
HEATHKIT ®
MODEL HD4418
NOTES:
1. ALL RESISTORS ARE TIA-WATT, 55 UNLESS MARKED OTHERWISE.
RESISTORs VALUES ARE IN OHMS III-1.000. M-1.ooo, DODI.
2. ALL CAPACITOR VALUES ARE IN ur IMICROEARADSI UNLESS
MARKED IN PF (PICOEARADSI.
3. O INDICATES A WIRE CONNECTION ON THE CIRCUIT BOARD.
4. 4- INDICATES A CHASSIS GROUND.
5. 47 INDICATES A CIRCUIT BOARD GROUND.
6. C ) INDICATES A Dc VOLTAGE (2201.! MEASURED WITH A
HIGH IMPEDANCE VOLTMETER FROM THE POINT
INDICATED T0 CHASSIS GROUND. ALL MEASUREMENTS
WERE TAKEN WHILE THE FILTER WAS GEING POWERED
BY A IA-VOLT POWER CUBE.
1. ALL PUSHDUTTON SWITCHES EXCEPT POWER ARE SHOWN IN THE
OUT POSITION.
3. ALL COILS ARE HAND-WOUND. IVALUES ARE NOT GIVEN).
an THESE VOLTAGES MAV VARY WITH DIFFERENT SWITCH AND
CONTROL SETTINGS. W01:
HeathCompany
magnum
mummmam

Part of 595-2980