Heathkit HD 1420 Schematic

Page 1

: CIRCUIT BOARD

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6 -u-II-llIan-.--nun-In-..---u-¢|n---I-

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HEATHKIT
VLF CONVERTER
MODEL HD-1420

NOTES:

1.

N

All resistors are rated at 1l4-wa11, and have a 5%
tolerance unless otherwise nailed (K . 1000].

Capanitor values less than 1 we in F (microfarads):
mm 1 or greater ale in pF (pioutarads). unless
chemise ruled.

The following symbols am used on Ibis schematic
diagram:

----------n-n-n-ncunnnun-apnnnnuun-ICUIIn---_______n--------_--__-___-----------------nun-nun...

SCHEMATIC OF THE

Circuit board gmnd.

Chassis ground.

DC voltage reading taken wilh a high input im-

_l_ Clrwfl board wim com-section.
O

6.

5.

pedance voltmeler from the point indium to
chassis ground. Voltages may vary 2 1096

Switch SW1 is shown in [he on'posilion.

Rafe! lo me "Cirwil Board X+Ray Vlaw on Manual
Page 23 for lhe physical localions of parts.

Page 2

(Shown from the component side.)

Page 3

P399 2

Heathkita

SEMICONDUCTOR IDENTIFICATION

HEATH MAY BE
COMPONENT PART REPLACED KEY
NUMBER NUMBER WITH NUMBER
DIODE
D101 412-633 5082-4484 A1
TRANSISTORS
0102 417-169 MPF105 A2
0103 417-875 2N3904 A3
INTEGRATED CIRCUIT
U101 442-96 MC14966 A4
F L A T o a
N O T C H Ex
CATHODE C
(SHORTER LEAD) 8