Heathkit IO-4205 User manual

HEATHKIT ®
MANUAL
5 Megahertz
Dual Trace
Oscilloscope
Model 10-4205
595-2072
·. '· .
.·':::;_·. 7 ... ~:··· ...::: ..... .
. · ..
, ,,_ ;~~:. ·.: .. · .: .. · ::·.:.~--~ 0
L~~-;·-~
HEATH COMPANY • BENTON HARBOR, MICHIGAN

HEATH COMPANY PHONE DIRECTORY
The following telephone numbers are direct lines to the departments listed:
Kit orders and delivery information
... . .... . ...... .. . . .. . [phone]
Credit
...... .. . . ...... ..... ....... .. ....... ... .. . ... . [phone]
Replacement Parts .
.... ..... ..... . . . ... .. . .. .. . .. .. ... [phone]
Technical Assistance Phone Numbers
8:
00A.M. to 12 P.M. and 1:00 P. M. to 4:30P .M., EST, Weekdays Only
RtC, Audio, and Electronic Organs . .
.. . . ...... ... ...... [phone]
Amateur Radio
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Test Equipment, Weather Instruments and
Home Clocks . .
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Television
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Aircraft, Marine, Security, Scanners, Automotive,
Appliances and General Products
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Computers
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YOUR HEATHKIT 90 DAY LIMITED WARRANTY
If you are not satisfied with our service- warrantyor otherwise- or with our products, writedirectly to our DirectorofCustomer
Services, Heath Company, Benton Harbor,
Michigan 49022. He will make certain your problems receive immediate, personal
attention.
Our attorney, who happens to be quite a kitbuilder himself, insists that we describe our warranty using all the necessary legal
phrases in order to
comply with the new warranty regulations. Fine. Here they are :
For a period ofninety (90) days after
purchase , Heath Company will replace or repair free ofcharge any parts that are defective
either in materialsor workmanship. You
can obtain parts directly from Heath Company by writing us at the address below orby
telephoning us at [phone]. And we'll pay shipping charges to get those parts to you- anywhere in the world.
We
warrant that during the first ninety (90) days after purchase, our products, when correctly assembled, calibrated, adjusted
and used in accordance with our printed instructions, will meet published specifications.
If a defective part or error in design has caused your Heathkit product to malfunction during the warranty period through no
fault of yours, we will service it free upon proof of purchase and delivery at your expense to the Heath factory, any Heathkit
Electronic Center (units of Schlumberger
Products Corporation). or any of our authorized overseas distributors.
You will receive free
consultation on any problem you might encounter in the assembly or use of your Heathkit product. Just
drop us a
line or give us a call. Sorry, we cannot accept collect calls.
Our warranty does not cover and we are not responsible for damage caused by the use of corrosive solder, defective tools,
incorrect assembly, misuse, fire, or by
unauthorized modifications to or uses of our products for purposes other than as
advertised.
Our warranty does not include reimbursement for customer assembly or set-up time.
~
This warrantycovers only Heathkit products and is not extended to allied equipment or components used in conjunction with ~
our products. We are not responsible for incidental or consequential damages. Some states do not allow the exclusion or ~
limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty
gives you specific legal rights,
and you may also have other rights which vary from state to state.
HEATH COMPANY ~
BENTON HARBOR, MI. 49022 ~
oROOo&~uoOOOootooooomo~
Prices and specifications subject to change without notice.

Heathkit® Manual
HEATH COMPANY
for the
5 Megahertz
Dual Trace
Oscilloscope
Model 10-4205
595-2072
BENTON HARBOR, MICHIGAN 490 2 2
Copyright © 1978
Heath Company
All Rights Reserved
Printed in the United States of America

Page 2
TABLE OF CONTENTS
INTRODUCTION o 0 0 0 0 0 0 0 0 0 0 0 0 0 o o o o 0 0 0 0 0 0 0 0 0 0 0 0 3
UNPACKING o o o o 0 0 0 0 0 0 0 0 0 0 0 0 0 o o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4
ASSEMBLY NOTES 0 o o o o o 0 0 0 0 0 0 0 0 o o o o 0 0 0 0 0 0 0 0 0 5
VERTICAL CIRCUIT BOARD
Parts List 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8
Step-by-Step Assembly 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11
HORIZONTAL CIRCUIT BOARD
Parts List 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 33
Step-by-Step Assembly 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 36
POWER SUPPLY CIRCUIT BOARD
Parts List 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 50
Step-by-
Step Assembly 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 52
CHASSIS
Parts List 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 59
Step-by-Step Assembly 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 61
INITIAL TESTS 0 0 0 0 0 0 0 0 o 0 o o o 0 0 0 0 0 0 0 0 o o o o o o o 0 o 80
CALIBRATION 0 0 0 0 0 0 0 0 0 0 o o o 0 0 o 0 0 0 0 0 0 o o o o 0 0 0 0 82
FINAL ASSEMBLY o o 0 0 0 0 0 0 0 o o 0 0 o 0 0 0 0 0 o o o 0 0 0 0 88
OPERATION 0 0 0 0 0 0 0 0 0 o 0 0 0 0 0 0 0 0 o 0 0 o o o 0 0 0 0 0 0 o 0 89
IN CASE OF DIFFICULTY 0 0 0 0 0 0 0 0 0 0 o o 0 0 0 0 0 0 0 o 97
SPECIFICATIONS 0 0 0 0 0 o o o 0 0 0 0 0 0 0 0 0 0 o o 0 0 0 0 0 0 106
THEORY OF OPERATION 0 o 0 o o o 0 o 0 o 0 0 0 0 0 o o 0 0 108
CIRCUIT DESCRIPTION o o o 0 0 0 0 0 0 0 0 0 0 o 0 0 0 0 0 0 0 109
SEMICONDUCTOR IDENTIFICATION
CHART 0 0 o o o o o o o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o 0 o 0 0 0 0 0 0 116
CIRCUIT BOARD X-RAY
VIEWS 0 0 0 0 0 0 0 0 0 0 0 0 0 Illustration Booklet, Page
36
SCHEMATIC DIAGRAM 0 0 0 0 0 0 0 0 0 0 0 o 0 0 0 0 (Fold-in)
WARRANTY 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Inside front cover
CUSTOMER SERVICE 0 0 0 0 0 0 0 0 0 0
Inside rear cover

; ; :
INTRODUCTION
The Heathkit Model 10-4205, 5 MHz, Dual-Trace Os-
cilloscope is a compact, versatile, easy-to-build, elec-
tronic instrument that you can use to study the
waveforms in electronic circuits. You can also use it
to measure frequency, and AC or DC voltages. The DC
to 5 MHz bandwidth and the excellent input sensitiv-
ity of
the vertical amplifiers allow you to use this
Oscilloscopefor nearlyall types ofwaveform applica-
tions . The triggered horizontal sweep circuit and the
many other outstanding features provide accuracy
and capabilities that are usually found only in higher
priced oscilloscopes.
Among the many other features this Oscilloscope of-
fers are:
• A
special TV position on the triggerselector.
This allows low frequencies to pass while
rejecting high frequencies, thus making it
Page 3
easier to trigger on the vertical frequency of
a TV set.
• A
10 to 1 attenuation circuit that can be used
for signals applied to the external, horizon-
tal
input jack.
• Accurately calibrated vertical
attenuators
with variable controls.
• A calibrated
time base (seven time base
selections, variable
within each selection).
These features, along with the attractive styling, will
make this Oscilloscope a welcome asset to the
laboratory, service shop, or the ham shack .

Page 4
UNPACKING
Inside the shipping carton was the box stamped PKl
which contained this Assembly Manual. With this
box removed from the shipping carton , you will find
bags
stamped PACK 2 through PACK 4. The Manual
will refer to these areas as "packs." You will be di-
rected
to open each of these "packs" as it is needed.
All other parts
in the shipping carton will be consid-
ered
the "final pack." Caution: Do not remove any
partsfrom their bags or the "final pack" until they are
specifically called for
in a Parts List in the Manual.
Eachassembly section of
the Manual containsits own
"Parts List" and "Step-by-Step Assembly" instruc-
tions.
At the beginning of each "Parts List," you will
be instructed to open one of the packs. You will also
be directed, in some Parts Lists, to remove certain
parts from the final pack.

Page 5
~~~~;allllll;ll:ll=u~ ......................................................................
ASSEMBLY NOTES
TOOLS
You will need these tools to assemble your kit .
PLIER S
DIA GON AL
C UTT ERS
------------------------------------------------- H
EA TH KI T
SO LD ERING
I
RO N
OTHER HELPFU~
TOOLS ~
/
NUT S TA R TER
1IMAY BE SUP PLIED
I WITH" KI TI
I
I
DE SO LDE RI NG
BUL B*
D
ESO LDER I NG
BR AID *
OR
PE NC IL
SO
LD ER I NG I RON
125 TO 40 WATT S!
I * TO REMOVE S OLDE R FROM CIR C UIT C ON NEC TI ONS .
·------------------------------------------------~
ASSEMBLY
1.
2.
Follow the instructions carefully. Read the en-
tire step before you perform each operation .
The illustrations in the Manual are called Picto-
rials
and Details. Pictorials show the overall op-
eration for a group of assembly steps ; Details
generally illustrate a single step. When you are
directed to refer to a certain Pictorial "for the
following steps," continue using that Pictorial
until you are referred to another Pictorial for
another group of steps.
3.
4.
5.
Most kits use a separate "Illustration Booklet"
that contains illustrations (Pictorials, Details,
etc.)
that aretoolargefor the AssemblyManual.
Keep
the "Illustration Booklet" with the As-
sembly Manual. The illustrations in it are ar-
ranged in Pictorial number sequence.
Position all parts as shown in the Pictorials.
Solder a part or a group of parts only when you
are instructed to do so.

Page 6
6. Each circuit part in an electronickit has its own
component number (R2, C4, etc. ). Use these
numbers when you want to identify the same
part in the various sections of the Manual.
These numbers , which are especially useful ifa
part has to be replaced , appear:
In the Parts List,
At the beginning of each step where a
component is installed,
In some illustrations,
In the Schematic,
In
the section at the rear of the Manual.
7. When you are instructed to cut something to a
particular length, use the scales (rulers) pro-
vided at the bottom of the Manual pages.
SAFETY WARNING:
Avoid eye injury when you cut
offexcess lead lengths. Hold the leads so they cannot
fly toward your eyes.
SOLDERING
Soldering is one of the most important operations you
will perform while assembling your kit. A good sol-
der connection will form an electrical connection be-
tween two parts , such as a component lead and a
circuit board foil. A bad solder connection could pre-
vent an otherwise well-assembled kit from operating
properly.
It is easy to make a
good solder connection if you
follow a few
simple rules:
1.
2.
Use the right type of soldering iron. A 25 to
40-watt
pencil soldering iron with a 1/8" or
3/16" chisel or pyramid tip works best.
Keep
the soldering iron tip clean. Wipe it often
on a wet sponge or cloth ; then apply solder to
the tip to give the entire tip a wet look. This
process is called tinning , and it will protect the
tip and enable you to make good connections .
When solder tends to "ball" or does not stickto
the tip, the tip needs to be cleaned and retin-
ned.

PARTS
Resistors will be called out by their resistance value
in 0 (ohms), kO (kilohms), or MO (megohms). Certain
types of resistors
will have the value printed on the
body, while others will be identified by a color code .
The colors of
the bands and the value will be given in
the steps, therefore the following color code is given
Page 7
==
OR
1/4-WATT
==fllm-===OR~
1/2-WATT
for information only. Multiplier
BANDS : 1 2 3 / /Tolerance 1-WATT
*Note Wide
Space
=======~--~=
2-WATT
Band 1 Band 2 Band 3 (if used)
Multiplier
Resistance
1st Digit 2nd Digit 3rd Digit
Color Digit Color Digit Color
Black 0 Black 0 Black
Brown 1 Brown 1 Brown
Red 2 Red 2 Red
Orange 3 Orange 3 Orange
Yellow 4 Yellow 4 Yellow
Green 5 Green 5 Green
Blue 6 Blue 6 Blue
Violet 7 Violet 7 Violet
Gray 8 Gray 8 Gray
White 9 White 9 White
Capacitors will be called out by their capacitance
value in JLF (microfarads) or pF (picofarads) and type:
ceramic, Mylar*, electrolytic, etc.
Some capacitors
may have their value printed in the following man-
ner :
Digit Color Multiplier
0 Black 1
1 Brown 10
2 Red 100
3 Orange 1,000
4 Yellow 10,000
5 Green 100,000
6 Blue 1,000,000
7 Silver 0.
01
8 Gold 0.1
9
EXAMPLES:
151K =:= 15 X 10 = 150 pF
759 = 75 X0.1 = 7.5 pF
Tolerance
Color Tolerance
Silver
:!: 10%
Gold
:!:
5%
Brown
:!: 1%
First digit of
capacitor's value: 1
NOTE: The letter"R" may be used at times to signifya
decimal point: as in: 2R2 = 2.2 (pF or JLF).
Second digit of
capacitor's value: 5
____ _,
Multiplier: Multiply the
first & second digits by
the proper value from the
Multiplier Chart.
To find the tolerance of
the capacitor, look up
this letter
in the Tolerance
columns.
* DuPont Registered Trademark
MULTIPLIER
FOR THE
NUMBER:
0
1
2
3
4
5
8
9
MULTIPLY
BY:
1
10
100
1000
10,000
100,000
O.D1
0.1
TOLERANCE OF CAPACITOR
10 pF OR LETTER OVER
LESS 10 pF
±0.1
pF
B
±0. 25 pF c
±0.5 pF
D
±1.0 pF
F
:± 1o/o
±2.0 pF
G ± 2°/o
H ±3
o/o
J ±5°/o
K ±
10%
M ±
20%

Page 8
VERTICAL
CIRCUIT
BOARD
PARTS LIST
Remove the parts from the pack marked #1. Check
each
part against the following list. The key numbers
correspond to the numbers on the Vertical Circuit
Board Parts Pictorial (Illustration Booklet, Pages 1
and 2). Any part that is in an individual envelope with
the part number on it should be placed back into the
envelope after you identify it until it is called for in a
step. Do
not discard an y packing materials until all
parts are
accounted for.
KEY HEATH QTY. DESCRIPTION
CIRCUIT
No. Part
No . Comp. No.
RESISTORS
All resistors are 5% (fourth band gold) unless designated 1 0%
(fourth band silver).
NOTE : The resistors may be packed in more than one en-
velope (stamped RES). Open all the resistor envelopes in this
pack before you check the resistors against the Parts List.
1/2-Watt 2 \.S
3L \ Y ; · tV\-G M ~ )
~ tcf-i ~ I R \05~
AI
(p- 15q
A1 6-279 3 2.7 n (Red-Viol-Gold) R179,
R181,
R182
A1 6-100 20 10 n (Brn-Bik-Bik) R124A, R124B,
R131A, R131B,
R142A, R142B,
R145A, R145B,
R157A, R157B,
R158A, R158B,
R159A, R159B,
R164A, R164B,
R166, R168,
R174 , R175
A1 6-220 4
22 n (Red-Red-Bik) R147A, R147B,
R148A, R148B
Some parts are marked with a " 171- " or "172- " pack-
aging number.
These numbers are used for packaging
purposes only and do not appear in the " Manual Parts
List."
To order a
replacement part, always include the
PART NUMBER. Use the Parts Order Form furnished
with the kit . If one is not available, see "Replacement
Parts"
inside the rear cover. For prices, refer to the
separate " Heath Parts Price List."
KEY HEATH
QTY. DESCRIPTION
CIRCUIT
No.
Part No . Comp. No .
Resistors (Cont'd.)
A1 6-330 {
33 n (Org-Org-Bik) R1A , R1B ,
R2A , R2B ,
::::ftj:() SA , R4059;
R106A, R106B
A1 6-390 2 39 n (Org-Wht-Bik) R151A, R151B
A1 6-470 2 47 n (Yei-Vioi-Bik) R134A, R134B
A1 6-820 2
82 n (Gry-Red-Bik) R144A, R144B
A1 6-101 6 100 n (Brn-Bik-Brn) R161A,
R16 · 1B,
R162A, R162B,
R171, R172
A1 6-201 2 200 n (Red-Bik-Brn) R117A, R117B
A1
6-221
8 220 n (Red-Red-Brn) R111A, R111B,
R113A, R113B,
R114A, R114B,
R183, R184
A1
6-271
2
270 n (Red-Vioi-Brn) R108A, R108B
A1 6-331 2 330 n (Org-Org-Brn) R116A, R116B
A1 6-391 6 390 n (Org-Wht-Brn) R135A, R135B,
R139A, R139B,
R153A, R153B
A1 6-471 2 470 n (Yei-Vioi-Brn) R136A, R136B
A1 6-511 2
510 n (Grn-Brn-Brn) R115A, R115B
A1 6-751 2 750 n (Vioi-Grn-Brn) R163A, R163B