Heathkit DX 40 Assembly Manual

Page 1

PRICE $1.00

Assembling

and Using Your. . .

Heathkit

AMATEUR
TRANSMITTER

MODEL DX-40

HEATH COMPANY

BENTON HARBOR, MTCHIGAN

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STANDARD COLOR CODE - RESISTORS AND CAPACITORS

INSULATED FIRST RING SECOND RING 'mnn) RING
AXIAI lEAD RESISTOR UNINSULATED BODY COLOR END COLOR DOT coma
lawn-Insulated Color First Figure Second Figure Multiplier DISC CERAMIC MA CODE
\\: § V \tk- Nam-insulated 3%?)VIEI (I) 0 None 5-D W", 3-D
\ k \ \ 1 0
§l§|§ \ = ED 2 2 "0 Multiplier
\\ \ ORANGE 3 3 ,000
§ \\ ~\ § YELLOW 4 4 0,000 1.1mm
Tolerant: GREEN 5 5- 00.000
see... 2 s 0333-000 .
Istnulhdsignifimnlfigwu - mo 1 .< If.
Vliu wound resist": have -��JVIEIAI¥E g g ogg'gggggg P u
m flail hm dmla wmh . .
RADIAL lEAD DOT RESISTOR EXTENDED RANGE TC CERAMIC IIICAP
Mulllplhr

ls! Fig-Io

Tollrullu

Mulliplior

TC Multiplier Tolerant:

Multiplier

RADIAL LEAD (BAND) RESISTOR
lAIIfiuIier

BY-PASS COUPLING CERAMIC CAPACITOR
(FINN

AXIAL LEAD CERAMIC CAPACITOR

Temp Cufl. (Filthy

Valor-u: H'MPIIII Tulomnu

The standard color code provides all necessary information re-
quired to properly identify color coded resistors and capacitors.
Refer to the color code for numerical values and the zeroes or
multipliers assigned to the colors used. A fourth color band on
resistors determines tolerance rating as follows: Gold = 5%,
silver = 10%. Absence of the fourth band indicates a 20%
tolerance rating

The physical size of carbon resistors is determined by their
wattage rating. Carbon resistors most commonly used in Heath-
lrits are % watt. Higher wattage rated resistors when specified
are progressively larger in physical size. Small wire wound
resistors 1A watt, I or 2 watt may be color coded but the first
band will be double width.

MOLDED MICA TYPE CAPACITORS

CURRENT STANDARD CODE RMA 3-DOT (OBSOLETE)? ' BUTTON SILVER MICA
"5mm zmzsignifignmfirye is: I. RATED 500 W.V.D.C. i 20% 0L. ((APACITOR
link (1) Multiplilr MIA . Multiplier Tel-rum it
coo: . . . Multiplier 95*
(In: 'Iolumm fizswfllfim'hfl" 3n! £in mg
I RM (5-001 OBSOLETE <00!) MA 64301 (OBSOLETE) RMA 4-001 (035mm)
so . . . w m _ l I '
wiSmufimfl film VI "9 =«® ® I'm! mil}si¢nillmnl Fiwns W k- v
mummy Mnllipliu 3rd or mg mg:
Fun ls! 1nd {Sin-limo" figure fl- .
_ Working V II Mull'pl' Multiplicr 5 \" ®_ Moltlpller
k: Roar I m P "I." M i Significant Fig-n
- Ioloma yum" blue-u Working Valley: I
, Voltage

MOLDED PAPER TYPE CAPACITORS

l . . MOLDED FLAT CAPACITOR JAN. CODE CAPACITOR
TUBULAR CAPACITOR flagsmfimw," (mmidm- SM mi mm
' "'IUP'I" Illrk Working Volts 2nd figur-
\~ \ \\ N \ s "'m'IV
a: N N \ \ N \ = a a I- m
slsls s es "T ' ' ,
1...... 2.4 sag-am... - Inhipliu III-WW
In} Volt-9c Figure 2nd

m::.'.:".:°:.:."::'.'r.:".:.z::r""°'~ lemme" «mm

The tolerance rating of capacitors is determined by the color
code. For example: red = 2%, green = 5%, etc. The voltage
rating of capacitors is obtained by multiplying the color value
by 100. For example: Orange = 3 X 100 or 300 volts. Blue =
6 X 100 or 600 volts.

In the design of Heathlrits, the temperature coefficient of eeramxc
or mica capacitors is not generally a critical factor and there-
fore Heathkit manuals avoid reference to temperature coeffi-

cient specifications.
(inflow of Centrulub

Page 19

( ) Trim one lead of a 1 megohm (brown-black-green) 1/2 watt resistor to 1/2" long. Connect
this short end to pin #1 on socket B (8-3). Connect the long end through pin #6, bend it up,
cover with a piece of insulated sleeving 3/4" long and connect the end to pin #2 on socket B.
Now solder pin #6 and #2. See Pictorial 2.

( ) Cut a piece of gray hookup wire to 7 1/4" long, trim the insulation 1/ " off each end. Con-
nect one end to #2 on DD (NS), run it close to the chassis, under the RF ground lead from
the 6146 socket and up to terminal #2 on the operation switch (S-l).

( ) Cut the leads on the 2 of paper capacitor to 1" long. Bend both leads inward and connect
to #1 and #2 on DD (NS).

( ) Cut the leads on the 12K (brown-red-orange) 2-watt resistor to 3/ " long. Connect one end
to #1 on DD (S-3). Connect the other end to #2 on DD (5-3). See Pictorial 2. This com-
pletes your speech amplifier and modulator circuit.

OSCILLATOR CIRCUIT WIRING

Consult Pictorial 2 for crystal switch numbering and wiring. You will note that there are no
contacts on switch positions #1 and #7 even though they are numbered

( ) Cut a piece of #20 bare wire to 7/8" long. Connect one end to crystal socket #4 (8-1). Con-
nect the other end to crystal switch #3 (3-1).

( ) Cut a piece of #20 bare wire to 3/4" long. Connect one end to crystalsocket #5 (8-1). Con-
nect the other end to crystal switch #4 (S-l).

( ) Cut a. piece of #20 bare wire to 7/8" long. Connect one end to crystal socket #6 (8-1). Con-
nect the other end to crystal switch #5 (8-1).

( ) Cut a piece of #20 bare wire to 2 1/4" long. Cover witha piece of insulated sleeving 1 3/4"
long. Connect one end to crystal socket #1 (8-1). Connect the other end to crystal switch
#9 (8-1).

( ) Cut a piece of #20 bare wire to 2" long. Cover with a piece of insulated sleeving 1 3/4"
long. Connect one end to crystal socket #2 (8-1). Connect the other end to crystal switch
#10 (8-1).

( ) Cut a piece of #20 bare wire to 2 1/4 long. Cover with apiece of insulated sleeving 1 7/8:
long. Connect one end to crystal socket #3 (S-l). Connect the other end to crystal switch
#11 (8-1).

( ) Trim the leads on a 100 K52 (brown-black-yellow) 1/2 watt resistor to 5/8" long. Connect one
end to #2 on the crystal switch (NS). Connect the other end to ground lug #2 on socket D
(S-l).

use NIL-Aw R6$l$TD"
WWW. Cover with a piece of insulated sleevingl 1/ " long.
Connect one end to crystal switch #2 (NS). Connect the other end to pin #2 on socket D
(S-l).

( ) Trim the leads on a 22 cut (red-red-black) silver mica capacitor to 3/4 long. Connect one
end to pin #1 on socket D (NS). Connect the other end to #2 on the crystal switch (8-3).

( ) Cut a piece of #20 bare wire toil 1,'/2 long and a piece of insulated sleeving 1 7/8" long
Insert one end of the wire through crystal switch terminal #8 (NS), through the sleeving,
and then through ground lug #1 ofsocket D. Bend the other end over and through the ground-
ed connection of the VFO input socket. Now solder just ground lug #1 and the ground con-
nection of the VFO socket. See Pictorial 2.

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