Keithley 1602B, 160B Service manual

Instruction Manual

Model 160B

Digital Multimeter

Contains Operating and Servicing Information
for Model 160B Digital Multimeter and
Model 1602B Digital Output

01975, Fourth Printing, December 1977

Keithley Instruments, Inc.

Instrument Division

Cleveland, Ohio, U.S.A.

INSTRUCTION MANUAL

MODEL 1606

DIGITAL MULTIMETER

(AND MODEL 16028 DIGITAL OUTPUT)

@COPYRIGHT

FOURTH PRINTING, DECEMBER

1975,

KEITHLEY INSTRUMENTS, INC.

1977,

CLEVELAND, OHIO, U.S.A.

CONTENTS

:,OOEL ibOJ

CONTENTS

-

SECTION
SPECIFICATIONS. .

I. GENERAL INFORMATION.

I-l, ,NTROD"CT,ON

......

........

. .

i-2. FEATURES
l-3. WARRANTY lNFORHATlON.
l-4. CHANGE NOTlCE

................

............

l-5. OPTIONAL MODEL 16028 D,G,TAL o"TP" T.
1-6. OPTIONAL MODEL 1688~ RECHARGEABLE BATTERY PACK

2. INITIAL PREPARATlON

................

2-l. GENERAL ...................

2-2. INSPECTlON.

Z-1.

PREPARATION FOR "SE

.................

3. OPERATlNG INSTRUCTIONS . .
3-l. GENERAL
3-2. HOW TO SELECT POWER. .
3-3. HOW TO MAKE INPUT CONNECTION!
3-4. HOW TO SELECT FUNCTlON

HOW TO MEASURE VOLTAGE

3-5.

3-b.

HOW TO MEASURE RESISTANCE.
3-7. HOW TO MEASURE CURRENT .
3-8. NOISE CONSIOERATIONS

.

3-9. THER"AL EHFS . .
3-10. MAGNETIC FlELDS .
3-11. AC ELECTRlC FIELDS .

.
*

3-12. SHIELDING. .
3-13. HOW TO "SE THE ANALOG OUTPUT
3-14. HOW TO USE MODEL 1608 OFF-GROUND . .
3-15. HOW TO USE MODEL

16028

DlGlTAL OUTPUT.

3-16. HOW TO RACK MOUNT THE MODEL 1608

4

THEORY OF OPERATION. . . . . . . . . : :

4-l.

GENERAL .

4-2.

ANALOG AMPLIFIER ClRC",TRY : : : : : :
4-3. ANALOG-TO-DIGITAL CONVERTER. .
4-4.

POWER SUPPLY . . . .

4-S.

MODEL 16028 DIGITAL OVTPUT . : :
ACCESSORIES. .

5.
MODEL 1601 AC DC PROBE
MODEL 1688A RECHARGEABLE BATTERY bAiK: :
MODEL 1683 UNIVERSAL TEST LEA0 KIT
MODEL 1600 HIGH VOLTAGE PROBE.

MODEL 1682 RF PROBE... .

MODEL 1609 CALlBRATlON COVER .
MODEL 1681 CLIP-ON TEST LEAD SET

6.. "AINTENANCE.

6-1. GENERAL.
6-2. REQUIRED TEST EQUIPHENT. t
6-3. PERFORMANCE VERIFICATION .

b-4.

7. REPLACEABLE PARTS.

ADJUSTMENT/CALIBRATION PROCEDURE

...........

7-l. GENERAL. .............

7-2. ORDERING INFORMATION

.......

7-3. SCHEMATlCS

.....

.

I

. .

.

.

PAGE

"

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k

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2
6

8"
8

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8"
9

IO

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Ii
12
12
12
12
12
14
14
16

22

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.

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23
23
23

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26

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32

32

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., .

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34
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35
37
45
45
15
45

ii

ILLUSTRATIONS

rzg. NO.

1
2 Tilt Bail Positions. ------------------------

3 *pant panel. -------------------------------------------

“fme”sio”al Data. --___--____-____-_____________________

4 *ottcm View Showing Line Cord. -------------------------

5

Rear View Showing Line Switches.

6 Mode11688A Rechargeable Pack. ------------------

IIcLe

-------__--_____--_____

Batrery
7 Exploded View of Model 160B/1688A.---------------------­8 Installatio" of Pack. -----------------------­9

Battery Test Location.

Battery

------------_----___------------­10 Front Panel Controls. -------------------_-------------­11 Imcarion of Protection Fuse. _---____-_________-________
12 Voleage Measurements "sing Model 1601 AC/DC Probe. -----

13 Current Measurements Using Made1 1651 Shunt. ---------­14 Floating operation. --_---__-__-_______________________
15 Model

16

16028

,,+&tal O”f,,“t. _____-____-___-____-________

Exploded View of Model 16011602B.

__-_-----__--____--__

17 lnstallati,,,, of &,&I 1602~. _---_______-____-__________

1.8 Rear Panel Digital Connector. -------------------

output
19 Timing Diagram for Model 1602~. -----------------------­20

Rack M,,unti,,g of Model

1.3,~.

__--_______--______________

21 Overall Block Diagram. _---____-___-____--_____________
22 DC Voltage Operation. -------------_----__------------­23 Resistance operation. __-____-_________--______________

24 current Operaelan. ------------------------------------­25 Absolute Value Deeector. ---__--_-________-_____________

26 LSI Block Diagram. ----_---___----___--_________________

27 A/D Converter Diagram. _--___-_________--_______________
28 Identification af Se~,ent.s and Mulriplex lines. -------­29 Tap and Bottom Cover Assembly. ------------------------­30 Locarion of Calibration Ad,ustmenfs. -----------------­31 Location of Test mints.
32 Location of Chassis Connections. ---------------------­33 Location of Fuses. ------------------------------------­34 case Outline - Integrated CirCUitS. -------------------­35 case Outline - Integrated circuits. _---_______________­36 Case Outline - Integraeed Circuits. _--____--_____--__­37 case Outline - Inregrated circuits. -------------------­38 case ourline - Transistors.
39 Case Outline - Thick Film Networks. _---__-_____-_______
40 Case Outline - Thick Film Networks. -------------------­41 Case O"tline - Custom LSI. ---_----_---_-_------------­42 Component Layout* pc-349. --_-_--______________________
43 component Layout,

pc-352.

----_---_-----____--_______I_

rage

iv
vi

1
3

4
4

;

9
11
13
13
14

15

16
17
18
*"

22

23
25
25
25
27
28
28
29
38
40
41
44
44
54
55
56
57
58

59
60
61
63
64

0976

SPECIFICATIONS

I

10.7

5

(27:

MODEL 1608

i

DIMENSIONS IN INCHES (MM)

I

FIGURE 1.

I

Dimensional Data.

1174

SPECIFICATIONS

Calibrated at 25” *ST

war,mte* to, 1 year

AS A DC VOLTMETER

AS AN OHMMETER

Liz2 m

NORMAL BENCH POSITION

LEVEL POSITION - TILTEAIL AT FRONT

J

&

45" POSITION

-

LEVEL POSITION - TILTBAIL%

MODEL 160B

SECTION 1.

l-l. INTROD”CTION.

digital multimeter capable of measuring voltage, cur-

rent, and resistance. me Model 1608 offers SeYen
ranges of voltage from lrn" to 1000 volts, nine ranges
of current from 1O"A to 1ooomA, and ten ranges Of re­sistance from 1n to lOOOM12. The Model 1608 display
is 3 digifs plus 100% overrange.

1-2. FEATURES.

a. Voltage sensitivity to 1 micravole per digit.

current .se"Giti"ity to O.OlnA per digit.

b.

Resistance sensitivity to 0.001n per digit.

C.

Floating capabilify LO _+1*00 "OlC.5 above case.

d.
e. Built-in analog output.

Optional Made1 1602R Digital Output

f.

Optional Model1688ARrchargeable "attery Pack.

s.

The Model 1608 is a wide-range

GENERAL INFORMATION

HANDLE AND
TILT BAIL

I

BAT TEST A

BAT TEST B

S

~

I

CONDENSED OPERATING INSTRUCTIONS

LINE

COW

STORAGE

S

S = SCREW
LOOSEN FOR
DISASSEMBLY

2

1174

MODEL 1608

INITIAL PREPARATION

5112 J113 !

520

I

ANALOG OUTPUT

SWITCHES SHOWN FOR

OPERATION FROM 105-125V LINE

DiGi

:TAL
'UT

OUTF

J302

3

L‘IG”RE 7.

Exploded view Of Model 1600,16881\

4

0976

I
I
I

BATTERi FUSES

F203, F204

I

SPACER

(4 PLACES)

MODEL 1608 CHASSIS

CAUTION

DISCONNECT LINE CORD BEFORE OPENING

THE TOP AND BOTTDM COVER,

LINE VOLTAGE ON THE CHASSIS

REPRESENTS A SHOCK HAZARD.

FIGURE 8.

Installation "f Battery Pack.

\\

0976 5

INITIAL PREPARATION

MODEL 160B

SECTION 2.

GENERAL.

2-l.
needed for incoming inspecrian and preparation for
use.

INSPECTION. The Model 1603 was carefully in-

2-2.

spected both mechanically and electrically before

shipment. "pm receiving the instrument, check for

any obvious damage which may have occurred during

f*El"Sit.

TO verify the electrical specifications, follow the

procedures given in Section 6.

PREPAR**ION FOR "SE.

2-3.
ready-to-use.
line voltage or from rechargeable nickel-cadmium bat­teries (when the oprional Model 1688A Rechargeable
Battery Pack is installed).

How to operate From IdlIe Power.

a.
provides a three-wire cord which mates with third-wire
;rounded receptacles (see Figure 4 for ~1% configura--

tion,.

by wrapping the card around the base of the i"str"-

ment as shown in Figure 4.

the permanently installed line cord is stored

wow to Set Line Switches. The Made1 1608 has

1.

two rear panel Line Switches which enable selection
of line voltages over ranges from x0-llO", 105125v,
195-235", or 210-250". TO operate from line power.
determine the appropriate line voltage range to be
used and set the Line Swirches as fallows:

I

This section provides information

Report any damages to tne shipping agent.

The instrument can be powered from

TABLE 2-1.

Summary of Line Switch Settings.

‘Jo-110” I

The Model 160~ is shipped

The Model 16OB

LOW. 117

105-125” NORM, 117

I

For example, if the line voltage ea be used is

approximately 115 volts, select NORM and 117 which

permits B range of operarion from 105 to 125v.
hfter line Switches are set, connect the line cord
and set the Power Switch to LINE.

210-250"

195-235”

1

LO", 234
NORM. 234

INITIAL PREPARATION

b. Row to operate From Battery Power. TO operate
the Model 16OB from batteries, the Model 1688A Re­chargeable battery Pack must be installed. The Model
1688A can be either field or factory installed.
batteries in the Model 1688A may need recharging be-

fare their first usage to power the Model 1600.)

The Model 1688A Rechargeable Battery Pack can
be insralled within the Model 1608 chassis at
any time.
Output is already installed, the Model 1688A

cannot be used simultaneously.

1. HOW to Install Model 168% Rechargeable Bat­tery Pack.
1688A come already installed in the battery pack.

the battery pack includes 7 rechargeable "C" cells

(1.2", 3 AMP HR) and 1 rechargeable pack (16.8V).

If baeeeries need to be replaced or re-installed,

be certain to observe the proper polarity of indi­vidual cells as shown in Figure 6. To install the
Model 1688A Battery Pack, turn the instrument over

so that the bottom cover faces up. Loosen four

slotted screws on the batrom cover as shown in

Figure 4. (A chisel-blade screwdriver is requires'

to loosen the slotted screws.) Turn over the in­strument with tap cover facing up, taking care to

hold the top and bottom covers together. Carefully

remove the top cover to gain access fo the printed

circuit board. (Two "ires that connect to the
Analog Oufput must be disconnected at the PC board
before the top cover can be set aside.) Check to

I

I

see that the four insulating spacers are in yasi-

tion on the printed circuit board. Place the Model

1688A Battery Pack in position an the spacers with

the cable oriented as sham in Figure 8.

4-wire Conneceor (5205) into the mating receptacle

(P205) taking care to orient the connector as
shown in Figure 8. After the Battery Pack is in­stalled. replace the top cover. Turn over the in­strumen; wiih bottom co&r facing up and tighten
down the four slotted-head screws.

Sumnary of nateerie Used in Model 1688A

However, if the Model 16028 Digital

The batteries furnished with the Model

(The

NOTE

Plug the

TABLE 2-2.

,.ine Fuse Requirements. The Model 1608 uses

2.

~VO line fuses to protect the line-operated power

SWPlY.
blow.

3. How to Replace Fuses in Model 1688A. The

!Jodel, 1688H uses 1 ampere fuses to protect the

power supply regulators in case of malfunction.
Fuses F203 and F204 are plug-in types and are lo­cated on pc board PC-349 as shown in Figure 8.
Keplace with 1 ampere, 3AB, slo-blo, Keithley Part
NO. FU-28.

6

ne fuse types are l/8 ampere, MB, slow-

Replace with Keithley Part No. F"-20.

Rechargeable "C" cell,

1.2". 2 AMP-FIR

Rechargeable battery

pack, 16.8V, .225

Am-m

1

TM-32

0976

The instrument must he operated in the BAT
mode in order t” obtain a valid battery con­dition at test points A and 8. This3 Will

enstire that tile batteries are supplying

power to the instrument. If the voltages

are measured when the Model 1608 is opera-

ted in the LINE mode a different reading

may be observed since the batteries are not

connected and rherefore do not supply power

to the instrumenr.

0976

OPERATING INSTR”CTIONS

MODEL 160B

SECTION 3.

GENERAL.

3-l.
needed to operate the Model 160B for measU*eme"f Of
voltage, cuirent, and resistance.

HOW TO SELECT POWER.

3-2.
powered from line voltage or rechargeable nickel-cad­mium batteries ("hen the Model 1688A is installed).
The Model XOB has a built-in line-voltage power sup-

ply and line cord.

chargeable Battery Set is ordered and installed, then

the user has the oprion of selecting line or bateery
operation via the front panel rotary power switch.

The accessory Model 1688A Rechargeable Bat­tery See may be ordered at ebe time of pur­chase of the Model 160B or may be purchased
and field installed at a later time if so
desired.

Wi*i"g. As a result, no modifications need

to be made to the Model 160B chassis.

a. "m, to Operate from Line Power. The Model 160B

can be powered from Line voltage over four ranges

from a minimum of 90" to a maximum of 25OV.
Table 2-1.

1. Set rear panel Line Switches to appropriate

positions as show" in Figure 5.

This sec~ian provides information

The Model 160B may be

If the accessory Model 1604 Re-

NOTE

me Model 1688A features plug-in

OPERATING INSTRUCTIONS

see

HOW TO MAKE INPUT CONNECTIONS.

3-3.

has two front panel terminals identified as "HI"

(red) and '3.0" (black). These terminals accomodate
banana plugs. alligator clips, spade lugs, bare
wirea, and other similar input connections. Leads
may be fabricated using a good quality capper wire

terminated by single banana plugs such as Keichley
Part No. K-5 or dual banana plug such as Keithley
Part NO. m-7. Ready-made test leads are also avail-

able from Keithley. Accessory Model 1681 Clip-o"

Test Lead Set includes two 40 inch long leads ter­minated by a banana plug and spring-loaded clip which

easily attaches co wires and terminals on pc boards,

Model 1683 Universal Test Lead Kit features in-

etc.

terchangeable probe tips for various applications.

'I%e Kit includes regular probes, alligator clips,
banana plugs. spade lugs, and phone tips. All-cow==

leads and teminarions are best for measurements on
the lm" and ln ranges.

3-4. HO" TO SELECT FUNCTION. Function is selected
by means of a single front panel Range Switch. llie
Range dial is marked in "en&wring" units for meas-

"remenf Of voltage (rn", V), C"r*e"t ("‘4, LL4, n!A), and

resistance (‘2, kn, M0).

the knob clockwise causes the Model 160B to switch

to a less sensitive range.

For each function, rotating

The Model 1608

3. Set front panel Power Switch to LINE.

b. "cm to Operate from Battery Power.

Install Mode11688ARechargeable Battery Pack.

I .

2. Check battery voltages at Teat Points A and

B to ensure thaL batteries are charged sufficiently.

1. If necessary, plug line cord info ac power
and set Power Switch to CHG to bring battery "alt­age up to useable levels.

4. When bartery level is sufficient, disconnect
line cord and set Power Swifch LO BAT.

switch

POSition

OFF
LINE
CHG
BAT

Line Connected

1688A not installed

OFF
ON
OFF
OFF

a. DC “catage. The voltage sectors of the Range

Switch are designated in millivolts ("IV) and volts

I", for full ranees from lm" to 1000". A full stop
it'the 1000 "&range prevents inadverranr switch­ing to the nanoampere ranges by clockwise rotation.

b, Resistance.

Lange Switch are designared in ohms (n), kilohms

(kn), and megohms (MO) for full ranges from 1 ohm

to 1000 megohms.

CU**e"t. The current sectors of the Range

C.
Switch are designafed in nanoamperes ("A), micro­amperes (,,A), and milliamperes (mA) for full ranges

franI 10 nanoamperes to 1000 milliamperes.

Condition of Instrument

Line connected

16888 installed

OFF
ON
ON
ON

The resistance sectors of the

Line not connected

1688~ installed

8

0976

POWER
S203

-ZERO
R114

- RANGE

SlOl

FIGURE 10. Front Panel Controls.

3-5. HO” TO ME‘“LS”RE “OLTIICE.
ures dc “aleage in seven ranges:
lV, lOV, LOO”, and 1ooov. Maximum dc input is 1200”

dc + peak ac.

a. How to Select Ra”E,e.
selected by rotating the Range Switch to the appro­priate position.
in millivolts CmV); four positions are direct-read­ing in voles (VI. Decimal point is selected by the
Kan,qe Switch. Polarity is automatically displayed.
If the input signal exceeds twice full range, the

display blanks (3 least significant digits) to in­dicate an “overran& condition.

Range

SeCti”

1000 v

100 v

10 v

,

100 mv

10 mv

*Maximum allowable input is 1200” dc plus
peak ac even though display can be read
beyond 1.200”.

Three positions are direct-reading

“01

1 v

1 In”

TABLE 3-2.

1tage Ranges Displ;

Max. Display

1999 *

199.9

19.99

1.999

199.9

19.99

1.999

The Model 1608 meas-

Im”, lOnl”, loom”,

Function and range is

d

b. How to Determine Accuracy. The xodel 16011 nc­curacy is iO.I% of readina f 1 dirit.
a display reading of 1.005 volt dc will have a” ,a,,­certainty of 10.1% f 1 digit or r.002 volts.
put resisrance in the dc m”de is 10 o,c~“,,cs. !,eai­urements from relatively high source resistnnccs
could cause an additional reading error.
of error due to loading can bc determined by rhc
following relatiansbip:

% error = 100 x RS i (R, + 10’)

where R, = Source resistance in ohms

For example, a so”rcc resistance “f 10,000 ohms Viii
result in a loading error of approximately 0.1% ai
reading.

The input current of the 1608 Cal” also cause
reading errors on the nlOSL sensitive vo1cage
ranges when high source resistances are pre­sent. For example, an input CUrrent of lOpA
and a so”rce resistvnce of MI! produce a”
error voltage of loll”.

c. Maximum Allowable Input. The maximum L”P”L to

the Model 1608 is 1200” dc + peak ac. On lrn”, lOn,V,
and lOOn,” ranges,
6OOV (12OOV momentary) dc + peak ac. ‘,‘hc ?,odel ,,SO”
can display dc voltages greater tba” r120O” but dnm­age to the input is possible.

the maximum conti”uox,s input is

For enarno1e.

The in-

The dln”“,:i

1174

0

OPERATING INSTR”CTIONS

MODEL L6OB

IMPORTANT

The Model 1608 provides ac rejection (NMRR)
of greater than 60 dB on the highesf range.
However, a large ac signal superimposed on
a dc level could cause damage if the input
CO the Model 160" exceeds 1200 volts dc +
peak UC.

d. How to Zero the Display. To accurately zero

the instrument, place a low-thermal short (such as a
piece Of clean copper wire) across the input rermin­als, set Lhe Range Switch to the lm" range, and ad­just the front panel Zero conerol for a flashing "i"
sign at the display.

The display should then read

t.OOO, with some flicker of the least significant

digit due to noise and A-D converter uncertainfy.
Once the zero has been set accurately, there should

be little reason to rezero the instrumenf again soon

when making measurements on the 10~1" through 1000"

ranges. The time stability of rhe zero setring is
excellent, and in applications requiring continuous
operation of the Model 160B, the zero setting will
hold for months. The front panel Zero control is
convenienf when making measurements on fhe 11"" Range.

A test set-up and cables when connected to the 160B
may cause offset voltages because of thermoelectric
effects (see section 3-9). These offset voltages
might be only a few microvolts or several tens of

microvolts. In such situations, the Zero control

can be used to buck out any initial offsefs.

I.""

thermal cabling and connections should be used when­ever possible. The instrument zero can also be check
ed, and adjusted, by shorring the input on any range

(voltage, current, or resistance).

me zero c**t*01
will have varying effects on the differenr ranges
depending on the sensitivity of the input amplifier,
but the zero control can be used in this manner.
Again, it should be emphasized, that for most meas-

"remene~ with the Model 160B, the Zero control can
be set once and then left untouched. (See also ?ec-

tion 3-6c "LO" Ohms Zeroing").

NOTE

With the input open 0" the lm" Range, the
Model 160~3 display may show a reading as

high as i.100. This 19 equ*va1ent to an
offset currene of lo.opA.

If the display

shows a reading grearer than t.100, then

the internal potentiometer, R121, should
be readjusted. Typically, ehe offset cur­rent will be less than 5p~.

HOW TO MEASURE RESISTANCE. The Model 1608

1-6.

measures resistance in 10 ranges: lsr, 1on, 10011,

Ikn, IOk&?, lOOk0, IM,,, lOMn, lOOK,, and 100011!2.

a. HO" to Select Range.

Function and range is
selected by rotafinf: the Ranae Swifch LO rhe BPPTO­priate position. Three posi;ions are direct-reading

in ohms (n): three positions are direct-reading in
kilohms (kn); four positions are direct-reading in
megohms (MQ) Decimal point is selected by Range

Switch. If the input signal exceeds twice full range,

the display blanks to indicate an "overra"& condl-

ti**.

TABLE 3-3.

Resistance current Ranges

Range Max. Impressed

setting LIiF3play units current

1. n 1.999 ii I InA

10 n 19.99 n lti

1 MI1 1.999 Mn 100 “A

10 Mn 19.99 MO 10 "A

100 Mr! 199.9 Mn I"‘4

1000 M* 1999 MO 0.1 "A

b. How to Determine Accuracy. The accuracy of cbe
Model 1608 is specified in terms of a nercen~ of
reading and a p¢ of range. For example, a dis­play of 1.000 kilohID (kn.1 will haw an uncertainty
of ~0.004kQ.

C. HO” to Measure “LOW” ohms. when making meas­urements on the ln, lOn, and 1OOn ranges, rhe Model
160B is to be zeroed on the IQ range. The zeroing
is accomplished by shorting the test leads together.
and adjusting the display for a flashing + and -

.ooon. By zeroing the instrument in this manner,
lead resistance of 200 mill.iohms (minimum) can be
compensated for. The instrument must be rezeroed on
the lil range each time a different set of iese leads
is used. Before making meaS"reme"tS right *t the in­put rerminals (no test leads used), rhe instrumene
should be zeroed on the iii Range after placing a
short, such as a piece of copper wire, across the
binding posts. Copper leads and clips are best for

making measurements on the ln Range, because the

voltage drop across a In resistor is only Im".

CAUTION

e. 80" to "se Model 1601 AC/DC Probe.
measuremenfs, connect the Model 1601 accessory K/DC
Probe to the Model 1608 inpur terminals.
Range to desired voltage range.

to AC.

"se the probe tip plus ground clip to make

Set switch on probe

connections to circuit under eesc.
complete specifications.

f.

How to "se Model 1682 RF Probe.
measurements, connect the Model 1682 Probe to the
Model 160B input terminals.

Set the Range to desired

TO make ac
Set the

see section 5 for

To make rf ac

voltage range. Maximum allowable input is 30" *Ins
ac, 200” dc.

10

Care should be taken when making resistance
measurements in circuits which may have volt­ages on capacitors, etc. or "here line volt­age is present. Although the Model 1608 is
fully protected against accidental voltages
up to 250" rms in resistance function, if
higher voltages are applied, damage may occur.

1174

-FUSE SHOWN FUSE SHOWN
TWICE ACTUAL SI

Range Max.

setting IDisplay Units

I,0 nA 19.99

100 nA 199.9

LO

100

1

1.

LB.4
,lh
UA

InA

1.999 II‘4 1040

19.99

199.9

1.999 n!A 10 il

Il.4
IL4

irA

UA

s,,une R*

10 rnA 19.99 In.4 I. 0

100

1000

lx.4

mi\

199.9 mA 0.1 !1

1.999

ti

1060
10%

10311
10%

0.1 G

OPERATING INSTR”CTIONS

MODEL 160B

d. HOW to "se the Model 1651 Current Shunt (for
meaS"remenfS to SOA). current measuremenf capability
Of the Model 160B may be extended to 50 amperes
through ctle use Of accessory Model 1651 SO-Ampere
shunt.

The Model 1651 permits 4-terminal connections
to minimize meaeuremene error.ciue to lead resistance.
To use the Model 1651, connect the voltage sensing
leads eo the Model 160B input terminals. Connect
separate current leads (not furnished) beuveen xhe
source and the large hex-head bolts on the Model 1651.
The current leads should be rated for currents up to
50 amperes. me Shunt resistance is 0.001 ohm, vhich
produces a sensitivity of lmV/Amp. As examples, 10
amps current results in a lOIn" drop on 1Oln" RANGE,
and 30 amps yields a voltage drop Of 3Oln" which can

be read on the loom" RANGE. Power diss*paCed in the

shunt is 2.5 watts at 50 amperes.

3-8. NOISE CONSIDERATIONS.

The 1imic of resolution
in voltage and current measurements is determined
largely by rhe noise generated in the source. stray

low-level noise is present in some form in nearly al1

electrical circuits. The instrument does not distin-

guish between stray and signal voltages since it meas­ures the net "olfage.

when using the lnl" and 1omv
ranges, consider the presence of low-level e1ectri­cal phenomena such as thermocouples (thermoelectric
effect), flexing of coaxial cables (triboelectric
effect), apparent residual charges on capacitors

(dielectric absorption), and battery action Of t"O
terminals (galvanic action).

3-11. AC ELECTRIC FIELDS. The presence of electric

fields generated by power lines or other sources can
have an effect on instrument operation. AC voltages
which are very large with respect to the full-range
sensitivity could drive the input amplifier into sat­urarion, thus producing an errOneo"S DC OUtpUt. At
line frequency or twice line frequency, the insLru­ment is capable of rejecting AC voltages whose peak-

to-peak amplitude is equal to the full-range DC sell-

sftivity on the loom" through 1OOOV ranges. This

level of interfering AC signal will produce no more

than 1 digit error.

On the lm" and 1OmV Ranges, the
instrumenf can reject line frequency and twice line
frequency signals whose p-p amplitude is equal CD 10
eimes the full-range sensitivity. Far example, on
rhe ID," Range, a 1OmV p-p, 50 Hz signal will produce

no more than 1~" (1 digit) DC erroi-.

Peak-to-peak AC

voltages greater than 1x the full-range sensitivity

o,, the 1OOm" through 1000" ranges, the 10X the full­range sensitivity on the lln" and 1omv ranges will
cause clipping in the AC section of the Model 160B
input amplifier.

For this reason, shielding is re-

com,,,ended when making sensieive DC voltage measure-

menrs, or when making measurements from high so"rce

impedances.

(See Shielding, Section 3-12.) The in­serunlent is also capable of rejecting frequencies
other than power line frequencies.

There is one pro­blem to consider; however, the input amplifier of the
Model l6OB uses a modulator to convert DC signals LO

AC signals before amplification. The drive frequency
of this modulator is 220 HZ nominally, f approx. 5%.

Interfering AC signals with frequencies equal to the
modulator drive frequency, or mu1tipl.e~ fhereof, will
appear 8.3 modulated DC, and produce large DC errors.

3-9.

THERMAL EMFS.

Thermal emfs (thermoelectric
potentials) are generated by thermal differences be­tween two junctions of dissimilar metals. To mini­mize the drift caused by thermal emfs, "se copper
leads to connect the circuie to the instrument. The
front panel ZERO control can be used to buck out a
cmstant thermal offset "aleage if necessary. The
Keithley accessory Model 1483 La" Thermal. Connecrio"
Kit contains all necessary materials for making very
low thermal copper crimp connections far minimizing
thermal effects.

3-10.

MAGNETIC FIELDS.

The presence of strong mag­netic fields can be a potential sw.,rce of ac noise.
Magnetic flux lines which CUt a conductor can produce

large a-c noise especially at power line frequencies.

The voltage induced due to magnetic flux is propor-

tional fO the area enclosed by the circuit as well

as the rate of change of magnetic flux. For example,

the motion of a 3-inch diameter loop in the earth's
magnetic field Will induce a signal of several tenths
of a microvolt.

one way to minimize magnetic pickup

is to arrange all wiring so that rhe loop area en­closed is as small as possible (such as twisting in­pur leads). A second way co minimize magnetic pickup

is to use shielding as described in Section 3-12.

3-12. SHIELDING.

a. Electric Fields. Shielding is usually necea­8arv when the insrrument is in the eresence of verv
l&e a-c fields or when very sensi;ive measuremen;s
are being made. The shields of rhe measurement cir­cuit and leads should be connecee* together to ground
at only one point.

This provides a "tree" configura-

tion, which minimizes ground loops.

b. Magnetic Fields. Magnetic shielding 19 useful

where very large magnetic fields are present. Shield-

ing, which is available in ehe form of plates, foil
or cables, can be used to shield the measuring cir­cuit, the lead wires, or the instrument itself.

C. Other Considerations.

1. Voltmeter Measurements. Use shielded input
leads when source resiseances are greater than 1
kilohm or when long input cables are used.

2. Current Measurements. On the mA and PA cur­rent ranges, no special shielding precautions need
be taken. However, an the 100 and 10 nanoampcre
ranges, shielded input leads are recommended.

3. llesiatance Measurements. Shielding of input
leads and source are recommended for measurements
on the 10 megohm through 1000 megohm ranges to pre­vent errOneO"S readings.

12

1174

FIGURE 12.

Voltage Measurements Using Model 1601 AC/DC Probe.

CURRENT TERMINALS

VOLTAGE TERMINALS

1

1174

;*

VOLTAGE LEADS

FURNISHED

OPERATING lNSTR"CTlONS

I

i+

--~ EXTERNAL

MODEL 1608

MODEL 1608

E%'

DC

FIGURE 14.

3-13. HOW TO USE THE ANALOC

has an analog output of il volt at full-range (non-

inverting) at up to 1 milliampere (2mA at 2 volts)
for recording or monitoring purposes.
analog output enables the Model 1608 to be used as
a la"-noise, low drift DC amplifier.

TABLE 3-5.

hi" at liNALOG OUTPUT

Range

1 In"

1.0 rn"

100 In"

For off-ground operarim, the analog output should
be connected only to equipment capable of operating
off-ground also.

is at the same poeential as the "LO" input terminal

of the Model 160".

3-14. HOW TO USE MODEL 1608 OFF-GROUND. The "LO"
terminal can be operated off ground at potentials

Of up tLl 11200".

to power line ground is specified at lOOOMn, or 10'0

(shunted by 300@).
tance from I.0 to GNE is two decades greater than
log!? (lO"O).
operating the Model 1608 off ground results in very

1.itr1e loading (from LO to GNU) of a floating source.

AC 1000" above ground, the Model 1608 will require,

typically, only 1Onh from the source.
i.solation also accounts for the high common-mode re-

x1000
x100
x10

The low side of the analog output

Isolation franI ehe "LO" terminal

Ty,,ically, the isolation resis-

Because of this excellent isolation,

Gain

OUTPUT.

Full Range

The Model 16OB

Also, the

OUtpUt

1"
1"

1"

The

excellent

CASE 8'

GROUND

Floating Operation

"across lk

The "isolation" capacitance from LO to GNC is impor-

tant when AC common-mode signals are present. in

the Model 1608, rhis capacitance is specified at 300
pF maximum.
has a reactance of approximately 10Mli. With the HI

terminal driven and a source impedance of lkll, R

1OOOV p-p, 60 Hz, common-mode signal will produce a
voltage of only loom" p-p across the Model 1608 in-

put terminals. This lOOmV p-p signal will be lurtbcr

rejected by the input amplifier and A-1) converrer SC

that the total rejection at the digital display is

at 1easL 140 LIB. At lower levels of *C common-mode

signals, the total rejection at the display is even

greater.

should produce only about 1 digit errur on the lh"

Range for a total rejection of approx. 160 dR. (IiT

driven, IkQ source impedance.1 WiCh both AC and IDC

common-mode signals, rejecti,, is lnuch greater than

specified when the Model 160B LO terminal is driven,

rather than the HI rerminal. Where there is a need

for even greater isolation from LO (0 power Line

ground, or where there is a need fo float at porcn-

tials greater than UOO volts above power Line ground
the Model 1688A Battery Pack should bc used.

TYPICAL

>lO"n ISOLATION

I

At a frequency of 60 HZ, 300 picofarads

For example, a 60 Hz, 100" p-p signal

RESISTANCE

= I x lkn = 10-a x 103 = lOll"DC

14

MODEL 160B

OPERATINC INSTRUCTIONS

out&t IO& “0” s &Sure f0 0~tp~f LO.
OUtput Device: 2N5089 or equivalent (greater than

25volt breakdown, less than 0.5 volt while sink­ing f15 milliamperes).

REMOTE CONTROLS:

Strobe: 6 lines for serializing in multiples Of 4

bits. Logic "1" inhibits controlled OUtpUt lines.

i’

O"t"UC Hold:

ing af DigitLOutput.

Display Hold:

reading (escept far polarity and decimal) at
“igital output and Display.

0976

I.oeic "0" retains data from last read-

Logic “0” retains data from last

15

CwmATING INSTR”CTIONS

MODEL 160B

3-15.

HOW TO USE MODEL 16028 DIGITAL OUTPUT.

a. General.

FIGURE 16.

The Model 16028 Digital Output provides

Exploded View of Model 1608/1602B

binary-coded decimal (BCD) ouepufs and several control

inputs.
installed" or "field-i"srallable".

2his accessory is available either

The Model 1602B

"fsctary-

consists of a single printed circuit baard (K-352)

with input and integrally mounted "u~pue ca""ecfar,

and an ouf,,"t mating cm,ne~tc,r with hoad.

b. Installation of Model 1602B.

The Model 16028

ia installed inrernal to the Model 160B and is DOW~I­ed by the Model 1608 line operated power supply:

NOTE

It is not ineended

used simulta"eously with the Model

that the Model 16028 be

1688A

Battery Pack. To use the Model 1602B. the

Model 1688A muse be remaved and set aside.

It is possible, however, for the u8er eo

make his own wiring modifications 8" that

the

Model 1688.4 Battery Pack can power rhe

Model 160B while lacated outside the Made1

160B.

DISCONNECT LINE COBB BEFORE OPENING

THE TOP AND BOTTOM CO"ER.

LINE VOLTAGE ON THE CHASSIS

REPRESENTS A SHOCK HAZARD.

CAUTION

To install the Model 16028. turn the Model 160B "ver

so mar: me DOttOm cover races up. Locate and loose”

.

four slotred scre"s as shown in Figure 4. The 8cre"B
are "captive" and should "at be completely removed.
Once the screws are loosened,

covers ragether and turn Wodel 1608

CO"Br- is up.

Carefully lift off rhe top c"ver and

disconnect the wires to the Analog Output.

hold

top and bott"m

so chat the top

Locate 16-

pin receptacle 5201 o" the ma,." circuit board W-349).
Plug the mating c""necLor (P301) from the Model 1602B
into 5201, after checking that pin numbers are corres­ponding. Locate Spin plug P208 on the main circuit
b"ard (PC-349).

P208.

Be sure that the

"A" af 5303.

Connect 5303

from the Model 1602B to

“A”

of PZOE lines up with the

Place Model 1602B board o" four spacers

with cables positioned as shown in Figure 17. Rem"ve

digital-output c"ver plate fram Model 160B fop c"ver.
Place t"p c"ver back on instrument, after reconnecting
Amlog output wires. Turn instrument 0"e-L and tighten
four slotted screws.

C.

Pi" Idenrif*cae*on of FleaI? Panel Digital OutpUt

connector.

(5302)

external equipment.

The Model 1602B uses a 37-pin connector

Co provide all input and output connections to

Pins are identified as shown in

Table 3-7.

16

0976

A DE

PZO8

(PC-3491

DIGITAL OUTPUT

CONNECTOR 5302

,J303

FROM PC-352

5303

1174

P301

(FROM ~~-352)

FIGURE 17.

Installatian of Model 1602B.

17

OPERATING 1NSTR”CTIONS

MODEL 1608

19

OUtpUt Data Lines.

d.

FIGmw. 18.

BCD (l-2-4-8) open-collector

Rear Panel Digital OUtpUt Connector.

positive logic represents each of 3 dv&a, OVerrange

digit, ""erload, decimal position, and polarity.

1.

open-collector output.

The output data buffers

of the Model 1602B consist of CMOS NOR gates driving
individual "open-callector" transistors. A main

fearure of open-collector outputs is the ability to

interface with a variety of data processing equip-

ment types including printers and campucers. The

open-collector output operates in eirher a saturated

(low-impedance) state or an open (high-impedance)

state.

including TTL, DTL, RTL, and CMOS.

It is compaCible with many Lypes of lagic

The Model 16028

OUtpUt lines can operate at voltage levels up to
+ZOV, and hence can interface directly with CMOS
circuits operating with +15V supplies.

I" most cases,

a pull-up resist"= is needed to define the "open"
or logic "1" state.

The value will depend on the
capacitive caupling among wires in the cable and to
other circuitry external to the Model 160B/1602B.

For operation with S-volt power supplies, a value
of Sk to 1Okn is usually sufficient, and the mini­m"!" value is about 3OOn. The Model 1602~ printed

circuit board is designed so that pull-up resis­to=8 can be mounted on the board itself (rather

than added externally). One end of the pull-up

resistors can then be connected to an excerna,.

power supply at pin 18 of the 37-pin output con­neceor (5302).

The PC board spacing is designed

for l/4 watt carbon resistors.

1

The open-collector configurafian can be

4.

used to connect multiple "utputs to one input of

a data-processing system. For example, if the
16028 is ineerfaced to a 16-bit compute=, ehe 3
BCD digits may be presented to a lh-bit data =e­@seer in the computer by setting lines 25, 5,
and 24 t" logic "0" at a given time.

If the DP,

overload, polarity, and 1 x lo3 outputs are wired

Model 1602B Connector Pin Ideneification.

TABLE 3-7.

1 Not Used
2

Not Used
3 DISPLAY HOLD
4 STROBE, ST-6
5 STROBE,
6

STROBE,

ST-2

ST-5
7 LO
8 DP-3 (100.0~
9

10

11

m-1 coooj

FLAG

OVERLOAD
12 DATA. 8 x 10'
13 DATA; 2 x 10'
14 DATA, 8 x lOI
15 DATA, 2 Y 10'
16 DATA. 8 x 10'

17

DATA; 2 x 10'
18 EXT VOLTS
19 Not Used

20 Not USed
21
22

Not Used

FLAG RESET
23 BCD HOLD
24

STROBE.

ST-3
25 STROBE; ST-l
26

27 w-2 (10.00)
28 m
29 POLARITY
30

STROBE, ST-4

DATA, 1 x LO3
31 DATA, 4 x LO2
32 DATA, 1 x lo2

33
34
35 DATA, 4 x 10'

36 DATA, 1 x lOa
37 Not USed

_- __-__-_--___

DATA, 4 x 10'

DATA,

1 x IO'

18

1174

MODEL 1608

"PERATINC INSTRUCTIONS

25

36

I-

STROBE 1

I x in0

17 2 x 100
35 4 x 100
16 8 x 100

5
34
15
33
14

24
32
13
31
12

I

18

STROBE 2

1 x 101
2 x 101
4 x 101
8 x 101

STROBE 3

1 x 102
2 x 102
4 x 102
8 x 102

EXT. VOLTS

b). When a particular 16”B/16028 is being op-

eraied, line 6 may be set to logic “O”, enabling

FLAG and FLZG. when the data from this particu-

lar 160BI1602R is not of interest, line 6 may be
set to Logic “1”. which disables FLAG ant, FnE.
men, ametIer device may use the same line for

interrupt or polling.

Pi” NO.

26

30
11

!

STROBE 4

1 Y 103 (““ERRANCE)
OVERLOAD

29 POLAKI'TY

6
10
28 Fix

!
1

STROBE 5

FLAC

Name

i

Since the dafa is in 4-bLr or smaller

cl.
groups, all output dafa from the 1602B may be
sequentially connected to a 4-bit bus using the
same technique described above. This is useful

when interfacing to progralmnable calculators and

logic systems where bit-parallel, character-ser­ial data tranSmiSSi0” is used.

3. nverrange Digit, Overload, and Polarity.
These three lines are controlled by the same strobe.
me presence of the overrange digit is indicated by
a “high” output. An overload condition is hdiC.9

ted by a “low” output. For polarity, “+” is repre-

sented by a “high” ourput.

OPEBATlNG niSTR”CTI”NS

3*

MODEL 1608

EVENT*

4* 5*

FLAG

BCD-----------­HOLD

;;:;T- - - - - - - ~- - -- - - - - - - - -~ ..- - - ~~. _ _ ..,,

I

DIGITAL OUTPUT DIGITAL OUTPUT
LATCHES UPDATED LATCHES UPDATED

I

/

I
I

-f----

~~I.-

2”

EXPLANATION OF EVENTS*

Conversion cycle #1 complete.

1).

2). Digital Output latches updated with data from conversion #l. "Flag" line goes
from "0" to "1".

"BCD Hold" goes low (after "Flag" line has gone high).

31.

"Flag" line goes high.

4).

sion #2, because "BCD Hold" line is low.

"BCD Hold" released (after "Flag" line has gone high).

5).

"Flag" line goes high.

61.
Flag Reset" goes from "1" to "0". causing the "Flag" to go from "1" to "0".

"Flog" line goes high even though "Flag Reset" line is still low. Digital Out-

latches contain data from conversion #5.

put

FIGURE 19. Timing Diagram for Model 1602B.

Digital Output latches still contain data from cower-

Digital Output latches now contain data from conversion

Latches in LSI circuit (in Model 1608) updated.

MODEL 1608

f. Output Control Lines. The Model 16028 has six

Strobe lines, a Flag Reset line, a BCD Hold, and a

Display Hold.

1. Strobe Lines. All data outputs are grouped

into 3- and 4-line groups. .Eachgroup is controlled

by a "Strobe" line.

Flag and Flag are also control­led by a Strobe line. Logic "1" on a Strobe line
turns all the transistor "open-collector" outputs

off in a particular group. A logic "0" o" a Strobe

line enables the data to determine the logic states
Of the group.

3-s.

Section d (above) gives additional information

'rhe groupings are indicated in Table

on open-collector outputs.

Flag Reset Line. Flag may be reset at any

2.
time by setting Flag Reset to logic "0". The Flag
is reset by the transition of the Flag Reset line
from logic "1" to logic "0". The signal at the
Flag Reset line may be either a pulse or a level.

When a pulse is used, the pulse width should be at

least l"&C.

If a level is used, a logic "0" on

the Flag Reset line will not prevent the Flag from

going high when the next "good data" is available.

BCD Hold. If this line is set to logic "0".

3.

the data at the Digital Output will "at be updated
as conversions are completed. Flag will operate

normally.

When BCD Hold is returned to logic "1".

the Digital Output will be updated normally. New

data will be available beginning with the next

logic "0" to logic "1" transition of the Flag.

1

me BCD Hold is not synchronized with a particular
point in the conversion cycle. when the BCD Hold

line is set to logic "O", the "updating" pulses
to the Digital Output latches are blocked. If
the BCD Hold is activated during the time when

Flag is normally low, either "one of or some of

the Di@tal Output latches will be updated. If
the BCD Hold is released during the time when

slag is normally Low, only some of the Digital
Output latches may be updated at the next Flag
high.

For these reasons. the SCD Hold should

be acrivated and released only during the time

when the Flag is normally high (this is approx-

imately 200mS regardless of whether Flag Reset
is used). The BCD Hold should be activated after

Flag has gone from low to high; the BCD hold
should be released after the Flag has gone first

from high to law and then from low to high.

NOTE

The SCD Hold has no control over the "DP"

(decimal point) lines.

The logic states
of the data on these lines is determined
by the setting of the Model 160~ ~a"Se
Switch.

The Range Switch setting should
not be changed while the Digital OUtpUt
is in a "Hold mode".

4.

Display Hold.

This "Hold" line affects the

Model 160B LSI circuit directly. When this ""aid"

is applied, the numerical data present at the Model
160~. display and at the Digital Output is "at up­dated as conversi~na are completed. Tne Display
Hold line is activated by a logic "0". When Dis­play Hold is returned to logic "I", numerical
data at the display and Digital Output will be
updated normally.

The Display Hold is not synchronized with a par-

ticular point in

the conversion cycle.

If the

Display Hold is activated during the time that

the Flag is normally low, numerical data from
either the moot recent conversion or the co"ver-

sion previous to it may be retained. A similar
situation can occur if the Display Hold is re-

leased during the time when Flag is normally law.

The Display "old should be activated after Flag
has gone from low to

high:

the Display Hold

should be released after the Flag has gone first

from high co law and the" from low to high.

like the SCD

Hold,

it is very unlikely that ac-

Lln-

tivating or releasing the Display Hold during
Flag low time would produce mixed data at Cbe
display and Digital Output. If it does not
matter whether the retained data is from the
most recent Conversion or the co""ersio" imme­diately preceeding it, the Display Hold can be
applied arbitrarily. I" any operating system
however. the Display Hold should be synchronized
in some way "ith the Flag.

1174

FIGURE 20.

tick Mounting af Model 160B

3-16.

now TO RACK MOUNT THE MODEL 160B. The Model

1010 Rack Mounting Kit adapts the Model 1608 for
standard S-114 in x 19 in. rack mounting, with 11 in.
depth behind the front panel.

a. “sing two Phillips screws (Item 7) attach sup-

port Plate (Item 2) to Front Panel (Item 1).

b. “sing four Phillips screws (Item 7). attact,
left and right side Brackets (Items 3 and 4) to Front
Panel (Item 1).

d. Assembly of rack hardware ia complete except

for mounting of IrlStrune”t.

22

0875

MODEL 1608

T,,E”RY OF OPEKnTI”N

SECTION 4.

THEORY OF OPERATION

1174

CURRENT

SHUNT

RESISTORS

OPTIONAL
DIGITAL

OUTPUT

IlV OUTPUT

.‘i

MODEL 160B

summary of Voltage sensitivity.

TABLE 4-1.

Attenuator Amplifier Full-Range

Range setting SenSitiYity Gain

lrn" --- 1 m" Xl000

1" In"

100 m"

1 ”

l/l"0

_­_-

1" In" Xl""

1"" lnv Xl"

1" In" X10"

10 v l/l"" 100 In" x10 1 volt

100 " 1/10,0"" 1" mV

1000 " 1/1",""0 100 mv x10 1 volt

3. Filfer Network. Basically, the filter is a

l-section RC low-pass filter made up of R116, R117,

and C104.

Rl16 and R117 in series have a nominal
resistance value of 112kn. At 5" Hz, Cl04 (.S$F)
has a reactance of approx. 6k0, and with the 112kn
produces an attenuation of apprax. 20 co 1. This

attenuation gives the Model 160B a normal-mode re­jection spec of 60 dB above 1 digit on the 1OOmV
range, as an example. "6" dB above 1 digit" means

that the Model 16"B can re,ect a 1OOm" p-p, 50 Hz

signal an the 1O"mV range with no more than a 1
digit error. 1""mV p-p at 5" Hz would be reduced

to 5mV p-p at the output of the filter.

This 5mv

p-p, after "chopping" and amplifying is enough to

cause amplifier "104 to reach its maximum allowed
OUtpUt level.

A signal greater than 5m" at the
oUtpUt of the filter causes "104 to saturate. when
Saturation 0cc"r-s) significant DC error signals can
he produced at the output af ehe overall amplifier.

4. Modulator Circuit. This circuit converts an

input dc signal to an ac signal with a fundamental

frequency component of approx. 22" HZ. The fre-

quency of 220 Hz was chosen because this frequency

is not harmonically related to either 50 Hz or 60
HZ. The circuit utilizes a dual MOS-FET (Ql"2A
and Ql"2B) connected in a series-shunt configura-

tion. This type of eeries-shunt modulator main­tains high input impedance.

5. AC Amplifier. The ac amplifier uses a low­noise integrated circuit, "104. The amplifier feed­back network provides a gain of approx. 2000 at the
modulating frequency of 220 Hz, while maintaining
a gain of 1 far amplifier ("104) dc offset voltages.

6. Demodularor Circuit. The demodulator is syn­chronized with the input modulator. A JFET, 4103,

with low on-resistance is used to alrernately atten-

uate or pass ehe signal present at the output of ac
amplifier "104. The negaeive portions of the 22"

Hz ac signal are allowed to pass which produces a

"half-wave-rectified" negative dc signal at the in­put to dc amplifier, "105.

7.

DC Amplifier. This amplifier is composed of

resistors R128 and R129, capacieors Cl13 and Cl14,

and integrated circuit "105. The integrated cir-

cuit provides sufficient gain to bring the foral
open-loop dc gain of the overall amplifier to a

minimum of about 20 million. The feedback capaci-

tor. Cl13 and Cl14 in series, was selected to give
a noise bandwidth of apprax. 0.5 Hz fo rhe overall
amplifier when it is used at a closed-loop gain of
10"".

The integrated circuit, UlOS, must be capa-

Amplifier F"ll-Ra"ge

DC output

1 Volt
1 volt
1 volt
1 volt

X10"

1 Volt

ble of driving the feedback network (R160.4, B, C,
and D),

ehe A-to-D convereer, and ehe Analog Output

to t2 VDC.

8. Modulator-DemodulaCar "rive Circuit. CMOS

inverters, U103A and "1038, provide oppoatte phase

square .,,aves used to drive MS-PET modulator tran-

siseors Ql"2A and QlOZB. Inverter U103B also pro­vides a drive signal for demodulator JFET Ql"3.
Resistors Rl21, P.122, and R123, and capacitors Cl08
and Cl"9 effect the rise and fall times of the
square-wave drive signals. R121 adjusts the rise

and fall time of Ql"2A only, 80 that the total

charge, both posifiva and negative, transferred to

the input can be minimized. Any net charge at the

input creates a current, which in the Model 160B

is specified to be less than il"pA.

The frequency

of the drive signal is determined by the clock cir-

cuit and LSI "201. Circuitry in LSI "201 divides
down a nominal clock frequency of 9680 Hz to pro­duce 22" Hz.

9. OffseE Current Zero Circuit.

See section

4-Z&.

1". Front Panel Zero. The voltages across po­tentiometer R114 are set-up by a seable zener re­ference diode, VRl"1. and an IC op-amp. "102.

These voltages are approximately +2 "DC, which give
RI14 an adjustment range of approximately 45"uVolcs.
A typical Model 1608 has an internal offset of about

-l""uValts in the chopper amplifier. Hence. adjusc­ing the Front Panel Zero from end to end "ill typi-

cally produce aboue +lZS,,"olrs and -325v"olts.

This
"extra" adjustment a~ ehe negative end of the range
allows sizeable positive offsets to be compensated

for, as is the case when the Zero is used for tese

lead compensation on the law-ohms Ranges. 200~ of

test lead resistance will produce +ZOO,,"oles of zero

offset, which can be "bucked o"t" by the Zero con-

ti-"1.

(See also Section 3-5d). Zeroing of the

chopper amplifier output is actually accomplished

by having the "Zero" circuit either source or sink

whatever current is present in feedback resistor
R160". For example, an Offset voltage of -1llu" on

the feedback line produces a c"rrenf of -1,A in re­siseor R16"" (111.135n). A voltage of -1u"olt at
the wiper of Zero poteneiometer RI14 will produce
an equal current Of -1uA in resistor R115 (M").

With fhts zeroing scheme. for the chopper amplifier
output to be at zero, the voltage at the feedback

line will always be offset from the voltage at the
input by a constant, say for example. -1llu"olts.

(The feedback line connects to the junction of R16"C

and R160D).

24

1174

ANALOG AMPLIFIER

INPUT HI

INPUT LO

?I7

INPUT HI

INPUT LO

AC AMPLIFIER

ATTENUATOR - MODULATOR - A,

FIGURE 22. DC Voltage operation.

- DEMODULATOR

RANGE

SWITCHING

DC AMPLIFIER

w

I ',

OUTPUT

INPUT HI

INPUT LO

0

f-i+7

'I

FUSE

ox0

1

OVERLOAD

PROTECTION

FIGURE 23. Resistance operation.

Lr

RANGE SWITCHING

I

I
I

ANALOG

AMPLIFIER

1174

C.

“hnmlecer circuitry. This circuitry provides a

number Of fixed currents by using a Stable voltage re-

ference, a differential voltage amplifier, and a ser-

ies resistor.
voltage overloads Of 25” volts at the Model 1608 in­put terminals.

1. “oltane Reference. An adjustable divider made

up of resistors R1.05, 11106, and RI’“7 provides an
output of approximately -1”“nl” from a stable zener
reference, “Rl”1.

inverting input of the differential voltage ampli-

fier.
amplifier ourput is 311 accurate +l”“m” when the in­put terminals of the Model 1608 are shorted.)

2.

Differential Voltage Amplifier.

fier circuit includen UlOl, resistors F.102, R104,

K108, R109, Kll”, and prorection circuitry. me

resistors and 1C op-amp are connected as a unity
gain differential amplifier; resistor ~11” adjusts
the gain accuracy.

cuit is connected to a reference voltage.

inverting input is connected to the feedback volt-

age of the analog amplifier.
voltage is esual to the innur voltaee of the analoe

The circuit is also proLecte* against

This divider is cannected tcl the

(The divider is actually adjusted so that the

This ampli-

l‘he inverting input of the cir-

me *cl”-

Because the feedback

4. OverLoad Protection. when a positiw over­load voltage up CO f25O “DC is applied to the Model
1608 input terminals, CR101 is reverse biased and

prevents damays to IC amplifier, “101.

from the +250 “DC source is ttmxgh a current set­ting resistor and R102.

which prevents excessive currents in the low-value
current-setting resistors.
load voltage up to -250 VDC is applied to the input
terminals, Ql.O1 is biased to limit the current to
appvaximate1y 2mA. Maximum current possible from
“101 and Rl”2 at -250 “DC is approximately Z.Sti,

which is low enough to protecf the low-value current

seccing resistors.
positive overloads, and an approximate -6V zener
drop for negative overloads.
of U1”l.

4-3. ANALOG-TO-DIGITAL CONVERTER.

digital converter includes the following circuits:

an “absolute-value” circuit, a polarity detector, an
integrator and threshold detector, a,, ISI circuit, a
clock, an LED display, and display drive circuitry.

a. Absolute-value Circuit.

a positive DC output voltage regardless of the polar­ity of the input voltage.
by:

“0”f = k lhnl

K102 has a value of 49wn

when a negative over-

Q106 has a normal diode drop for

It protects the input

‘This circuit produces

The relationship is defined

where k = +1

current flow

me analog-co-

1

26

1174

ANALOG SIGNAL

1V = FULL RANGE

R16ZA,R134

TO POLARITY INDICATOR

LOGIC

1

R162F,G

Actual operation is as follows: A positive dc voltage

at p*n 12 of K162 produces an equal dc voltage at the
output of Ul”7, and also causes the output of U106 to
go negative. When this happens, CR105 is reverse

biased, and “107 is effectively isolated from the ac-

tion of “106. A negative dc voltage at pin 12 of RI62
causes the autput of “106 to 80 positive; the output
of U106 must go sufficiently posirive to forward bias
CR105 and drive the input of “107. In this situation,

U107 and Ul”6 together function as a two-stage invert-

ing amplifier. The gain of this inverting amplifier
is accurately set to -1 by internal adfustmenf R134
(“-DC CAL”) and rcsisrors R162A, R, and H. K135 (“RECT
ZERO”) sets the zero offset voltage of “106 equal f0

-l/Z the zero Offset voltage Of “107. rfhus, the zexo
offset is the same for hot-h positive and negative dc

signals, and this zero offset can be compensated far

with the “DISPLAY ZERO”,

C117, and cl18 provide filtering of AC components pre-

sent in the input signal.

R136.1 capacitors ~115, C116.

J

1

TO A/D CONVERTER

b. Polaricy Defector.
cuit uses TWO transistors, “108C and U1”8D, of an IC
rransistor array. These transi~rors are used as a

simple differential-voltage amplifier with one,output
connected LO y~~wer supply common. A positive-going
output “f “106 callses the collector of transistor
“1081~ to go negative. When this happens, Q206 is

shut off, and the “+” segments of display DS201 ~r’e
aha shut off.

:he base of transistor u108D to be clamped at apprax­imately -0.7”. which shuts off the collector current
of “108D. AS a result, the voltage at the collector
of 11108” gaes to a level of approximately +“.,“, which

is sufficient to drive Q206 into saturation and turn

on the “+” segments of “S201.

0976

A negative-going OUCPUC of U206 CRUSTS

The polarity detection cir-

CS
TH

7 SEGMENT

DECODER

I 1

DISPLAY
OUTPUTS

i

TO

DISPLAY

Cl 20

28

LSI CIRCUITRY

DETECTOR

OCLOCK

1174

a

1 +TL;f.;./y i

IDENTIFICATION OF MULTIPLEX LINES

PIGURE 28.

curacy. Once the reference current is set, a” input

of 250m" is represented as 250 counts out of 2016,

and 1.999" is represented as 1999 counts out of 2016.

An input of 2v or greater causes the 3 least-signi-

ficant digits to blank.

NOTI:

one comp1ere con"ersio" cycle is 2048 CO"rLfS.
The six counter is able to count to 2016 be-

fore it is stopped.

CO"*ltS, the information in the BDC counter is

transferred into latches, and then the "CD

counter is reset to Zl?TO. 2048 CO""tS at a

clock frequency of 9680 Hz results in a total
conversion time of approximately 0.21 seconds

(which is equivalent to about 5 readingslsec.).

d. Clock.

timer, Ll202, hooked up far astable operation. Rexis-

t,,rs ,I205 and R206, together with capacitor C201, set
up a non-symmetrical square-wave with a nominal fre­quency of 9680 HZ and a duty cycle of about 5%. 4201,
along with R202, R203, and R204 is used to invert the
output of uzm.

"isplay. The Model 1608 digital readout is

e.

,nade up of three LED seven segment displays (DS202,
~203, and uS204) and one LED "21" display (DS201).

1. Display Multiplexing. The LED displays are

znultiplexed to minimize the number of interconnec-

tions, simplify the drive circuitry, and reduce
power consumption. The timing for the multiplexing

The clock circuit makes use Of an IC

During the remaining 32

Identification of segments and Multiplex Lines.

f

,,I

e

dp .

IDENTIFICATION OF SEGMENTS

is determined by the LSI circuit, L201. and is see

up such that each mu1cip1ex line is hi& for 8

clock pulses (;~pproximately 825uSec.1 and low for
24 clock pulses.

signated as TO, Tl, T2, and T3, and each line cun-

trols an LED display (See Figure 28). Circuit opera-

tion during a particular multiplexing interval. say
TO, is as follows: when TO is high, the oucpuc Of
"20% is 10". This produces a CUrrelIt in R218B Of
approximately lOmA which is sufficient to drive
Q202 into saturation, and effectively c"nnect 1~5201

to the f5" power line. Simultaneously, the LSI

circuit supplies the correct digital information

for DS201 to the display segment ciriuers.

circuit action the" occurs during the oe,,er multi­plexing intervals --- 'i‘l, T2, and T3.

2. Display Drive.
signed to handle a variety of LED common-anode dis­plays. Because 't~~nstant--current" drivers are used.

displays with different voltage drops per sewent

can be drive" without changing the circuit power
conaumptian. The driver* take the same current
from ehe C5" power supply regardless of whether
the display segment drop is 1" or 3.5". Actam
operarion of a particular segment, segment h for
example, is as follows: when the "A" 1inc of LSI
circuit "201 is high. the" the open-collector DUt­put of buffer U204A is shut off.
voltage at pin 5 of resistor network R211 is spprox­imarely 11.3". which is also the voltage at pin 9
of transistor array "205. nssuming a base-to-em­itter voltage of 0.7". Lhen the voltage at pin 10
Of "205 is approximately i4.6"; this voltage gener­ates a 15,nA c,,rrent in the 400 emitter resistor.

I I

d

The four mulriplex lines are de-

b

c

The aan,e

The display drivers are de-

AS a result, LhC

0976

29

THEORY OF OPERATION

MODEL 1608

When the “A” line of U201 is low, then the output
of "204,, is also low, and the transistor current
source (pins 9, 10, and 11 of 11205) controlled by
"204A is shut off.

Transistor 4207, and ifs assoc­iaCed circuitry duplicates the operation of the other
six transisror current sourcgs.

The “decimal point”
lines of 115202, DS203, and OS204 are controlled by
the Range Switch, and the currents for the decimal
points are determined by R209, R210, and R211.

4-4. POWER SUPPLY.

the Model 1608 uses either line
power or battery power (when the Model 1668A is in­stalled).

a. Line Power.

Transformer I’201 has two tapped
primary windings which are connected in series or in
parallel depending on the position of line switches
5201 and 5202.
4-5-6 for all settings.

Fuse F201 is in series with winding

Fuse ~202 is connected only

when winding l-2-3 is connected in parallel with wind-

ing 4-5-6. The secondary of I’201 has two tapped wind­ings. T,,C lower caps (11 and LO; 8 and 7) are used

in line mode. 'The upper taps (12 and 10; 9 and 7) are

used in charge mode.

1. +5v Supply.

In LINE operation, the ac “olt­age between transformer leads 10 and 11 is full-wave
rectified by CK203. The filtered full-wave dc volt-

age (approximately 10”) is regulated by integrated

circuit u207.

The outpur regulated voltage is 5”

15%.

2.. -12” Supply. I” LINE operation, the voltage

between transformer leads 7 and 8 is full-wave rec-

tified by CR204.

The filtered full-wave dc voltqe

(approximately 18") is regulated by integrated cir-

cuit U208.

The regulated output voltage is -12”

i5%.

b.

Battery Power. When “ATTERY mode is selected,
the Mode11668ABattery Pack is connected into the in­puts of u207 and U208 while the line voltage is dis­connected at the secondary.

vide input power for the l 5” supply.
tales provide input power for the -12” supply.

The 8.4” batteries pro-

The 16.8" bat-

Bat-

tery test point h provides a measurement of the 16.8”

battery supply with respecr to power supply low.

Therefore, the voltage measured is the difference bc-

tween the battery supply and the -12 vole uurput which
is approximately +4.8 volts. nartery LCSC point R
provides a measurement of the 8.4” battery supply.

Battery Char&q. In the Charge mode, rbe 8.4”

ba;;er*eS are connected between the output of CR203

and the input of U207.

‘TO accommodate the barteries
in series with the regulator (U2071, one AC input oI
CR203 is switched to a higher voltage rap (pin 121 on

eransformer T201.

‘The 16.8” batteries are connected

between CR204 and “208. and CR204 is switched to pin

9 af T201.

Actual charging of the 8.4” batteries is

accomplished by the current pulses in filter capaci-

ior C203; charging of ehe 16.8” batteries is by cur-

rent pulses in C206.

Pin Identification for LSI.

TABLE 4-4.

Pi”

NO.

“Wig. FU”CLiO”

/

1 f I Segment drive

2 8

) Segment drive

“altape l.C”ClS

l 5” = ON, 0” = OFF 15 dp 1 Decimal point ~ +5v - ON, 0” = OFF

+5v = ON, 0” = OFF

3 iT1 ~ Multiplex line f5” = ON, 0” = OFF

Pi”
lie. Ilesig.

16
17

:44 I

‘TO ~ Multiplex line +5v -

I

4 , T3 Multiplex Line
5 : HOLD i

6 MR
7 TH

Not "se*

1 Threshold input +5” or -12”

8 1 CM Clock

+5v = ON, 0" = OFF

,

____ ____

Approx. lOk”Z, +5v LO -12” 22 C”M ~ common or “LO” 0”

18 Fl
19 i F4
20 1 +5v Power, f5"
21 I -12" ,~ Power, -12"

9 b : Se,,q”ent drive +5v = ON, 0" = OFF 23 ~ CN ~
10 a
11 d
12 e
13 c Segment drive

Se,qent drive
Segment drive .+5” = ON, 0” = OFF

+5v = ON, 0" = OFF 24 i ~2

25 IR4 i

Se~tnent drive +5v = ON, 0” = OFF 26 8.1

f5" = ON, 0" = OFF 27

/ R2

14 cs Current Switch I+5” = integrate mode

I

FunCtion

I

I

Not Used

) Not Used

~ ?utip1ex line

Nat Used
Not Used
Not Used

Not “SCd

Voltage Le”els

ON, 0” = OFF

! ---­: +5v

-12"

i +5v = ON, 0" = OFF

_---

_---

30

0976

a. SeVerI segmell-to-BCD canvercer. ‘This converter

uses one Hex Inverter n!301).

three "uad 2-InnuT NOR

C. OUtpUt Data Buffers.

The dara buffers consist

basically of five Quad 2sInput NOR gates (U314 thraugb

SECTION 5.

MODEL 1601 AC-DC PROBE

GENERAL. The Model 1601 is a combination ac-dc probe

that enables the user fo measure "oltqes from 45 Hz

to 45kHz when used with the Model 160B. The slide
switch (SlOl) can be used to select either AC mode
or straight-through DC Mode.

SPECIFICATIONS:

DC: straight-through probe does not alter any

Model 1608 specifications except:

farads input capacitance 2) 0.5 atqere maximum
current 3) 0.3 ohms resistive offset 4) i20 micro­volts rhermal offset.

w (Voltage only):

RANGE :
TRANSFER ACCURACY:

INPUT IMPEDANCE:

MAXIMUM OVERLOAD: Peak ac plus dc must "of exceed

250 volts nns maximum.

f3% of reading, 10.1 volt, 45

Hz to 45kHz into a LOWi 110% load. Peak respond-

ing, calibrated in rms of a sine wave.

0.5 megohm, shunted by less than

20 picofarads.
400 "OltS.

1) 150 pico-

ACCESSORIES

MECHANICAL PARTS LIST:

Item

NO.

1 TiP
2 Bady, Front

3 Body, Rear
4 Strain Relief
5
6
7 Insulator (Black)

8
9 strain Relief

Cable, Ground (13" long)
Clip, Alligator (Ground)

Cable (40" lo"=)
Can Shield

Description

246548
24656C
24655C
186768

SC-33
*C-lo
AC-11
SC-30

18676~

25128‘4

CONNECTOR:

DIMENSIONS, WEIGHT:

(150 x 20 "In),

pound (0,l kg).

MAINTENANCE:

Since the probe assembly should provide goad service
with normal handling "o maintenance is usually "ec­WSClry.

rogether at the factory using a special salvent.
Therefore ebe probe should not be disassembled. If
repair is necessary, contact the Keiebley Represen-

tative in your area.

ELECTRICAL PARTS LIST: (See schemaeic 24669C)

JlOl
SlOl
Cl01

Cl02
DlOl
0102
D103

RlOL
R102
KL03
8104

Shielded Banana Plug.

6 in. long x 314 in. diameters

3 ft. (1 m) cable, "et weight l/4

The probe body (Items 2 and 3) is fastened

Banana Plug (2 req'd)
Switch, AC-DC RI
capacitor, 0.047pF STAND

capacitor, 0.1 pF POT
Tra"SistOr, ieN, case TO-106 FAIR
Tra"SiSfOr,
Diode
Resistor, 3.92 MR, 1%. 1/4w, CbF
Resi6tor, Selected in Test*
Resistor, 1 MI, o.l%, l/El.?, MtF
Resistor, 100 0, lO%, 1/4W, Camp

NPN, case TO-106

Mfr.

Code

JOHN

FAIR
MOT
DALE

IRC

DALE

OHM

Mfr.
Part NO.

108-750-Z
speckI
MZW-F-0.047uF
MWLA-O.~UF
2N3565
2N3565
IN4006
DC-l/4-3.92M
CEA-TO-"

MFF-L/8-LM

CB-101-10%

w-3

SW-334

C197-.047M
C86-.1M
TG39
TG-39
RF- 38
R178-3.92M
R88-*
RL79-1M
R16-100

32

1174

operate Time: continuous operation of Mode1 16OB

from full charge is 6 hours minimum.

Recharge Time: l-112 hours per hour of discharge

(fully charged witbin 12 hours),

Added Weight:

2 pounds (1 kg).
Added Fowcr When Charging: 4 watts.
Fused for I, ampere.

stora,qe Temperature: -25’C to +45°c

Description: The Model 1683 is a set of flexible test
leads, 40 in. (1 m) in length, with interchangeable
screw-on adapters.

contents :

c . nescripeion

2 Test Leads, 40 in. (lm) 1 red, I black

4
4 Banana plug adapter
2 Probe. 1 red, 1 black
2

Alligator clip adapter

Spade lug adapter

2 Phone tip adapter

Model 1600 High Voltage Probe

The Model 1600 High Voltage Probe may be used with a
voltmeter havinga nominal input resistance of 10 megohms

in the dc volts function. The division ratio is 1000

to 1. The maximum voltage which can be measured is

40

kilovolts.

“O,.TAGE RANGE: 0 to 40,000 volts cl=.*

INPUT RESISTANCE: 1000 megohms.
DIVISION RATIO: 1000:1.
RATIO ACC”RACY (WITH 10Mi LOAD): !1.5% at 25k”, decreasing C”

*2.0% at 20k” amI 30k”,

~3.0% at lOk” and 40k”, and

14.0%

at Ik”.
RATIO STABTLITY: 0.01% per “C, rO.l% par year.
HEAATING EFFECTS:

Self-heacing due to application or high “oltagc for periods in excess

of 1 minute will cause a maximum of 0.2% additional error at 40kV (error is less at

lower ““ltages).

ENVIRONMENT: o*c to 50°C. 0% to 80% relative humidity up to 35*c.

70°C.

DIMENSIONS, WEIGHT: 3 in. maximum diameter x 15-l/4 in. long (76 x 387 mm). 4-l/2 it.

(1.4

m) cable and ground clip lead to banana ,‘l,u~.

*AC resnonse UC Ik” is float withii, 110% from 20 HZ t” 120 NE.

1277

Net Weight:

SfOragC:

12 OZ. (341 g).

-25°C to

division ratio is dcpen

33

Model 1.6K2 RF Probe

34

127,

SECTION 6.

MAINTENANCE

Item

A
K

c

”

E Resistance source

F Ohmmeter

G

H

kscri_Frion
“altmerer, Digital lO.“O” e 0.2% Keirhlcy
Voltage source

Voltage Divider 100:1 @ 0.01% ESI

current source

Resistance source*
Resistance smrce* 10911 @ 1%

Minim”“, Specification

1,10,100,1000” tic @

0.005%

1000:1 @ 0.025%
ImA, lOmA, loom*, 1A

@ 0.02%

1G @ 0.1%
1OII @ 0.04%
loon, xa, 1OKIi
loom, lMrl, 1OMIi e 0.02%

loon @ 0.4% Keirhley
1om @ 0.3%

lo*!> e 0.25%

*(resistor in shielded

enclosure)

Manufvciurcr

Fluke

Fluke
General Radio

i4elhyn

wzlwyn

Node i

168

343A
622:\11~0K

382A
1433-H

168

N14-l”b.25%
ml-109-l%

I

MAINTENANCE

MODEL 1608

summary of Battery Voltage Levels at Test Points

TABLE 6-2.

Test Recharge Batteries
Point Range Normal If Below Tested

A 2.5" to 9" 4.8V - 2.5" L-29

B 7"

Input Kesistaoce Check.

b.

to 10.5" 8.4" 7" BA-30

1. Select 1000" range.

2. Measure input resistance using Ohmmeter (F).

3. Resistance should be 10 megohms ? 1%.

c. Voltage Accuracy 3. *

1. select lrn" range.

2. Apply a short (low-thermal copper) to the

input terminals.

3. Adjust frone panel Zero Control (R114) as

necessary to achieve a +.OOO display.

4. Remo"e short.

5. Verify that the Model 1608 reading is within
tolerance stated in Table 6-4 for Ikn, lOk:i, 100k:i,
UW, and LOW ranges.

6. connect Resistance source CC).

7. Verify 1ooMs range.

8.

connect Resistance source (H).

9. Verify lOOOlG range.

TABLE 6-4.

Accuracy Check for ResFstance

1n 20.1%

10 $1 10.04%

100 n iO.OZ%

Iki2 iO.O2%

lOkn 20.02%

loo!4 ?0.02%

lMn ?0.02%

1Ol.K iO.O2%

lOOM0

1ooom

?0.5%
22%

1.000 n 15 digits

10.00 12 '4 digits

100.0 II 24 digits

1. OOOkG 14 digits
10 . OOki> ?4 digits
lOO.Okn +4 digits
1, OOOMn

10.00MO

'4 digits
?4 digits

100. OMQ ilO digits
1000 Mri t301 digits

**See Specificarlona for temperature coefficient

for resistance.

6. For each voltage range, verify that rhe Model

160s reading is within the tolerance stated.

d. Resistance Accuracy Check.

1. Select the 10 range.

2. connect Resistance Source (El to input and

adjust Model 1608 zero for a i.0000 reading.

3. Verify that the Model 160B reading is within
the tolerance stated in Table 6-4 for 10, IOP, and
loon ranges.

4. With Resistance Source (E) connected and set
to On, select the 1mV range and adjust the Model
16OB zero for a ~.OOOmV reading.

Accuracv Check for DC "oltaee

1.000000 ” 0.001

1.000000 " 0.01

10.00000 v 0.01

1.000000 " _-

10.00000 " __

100.0000 " __

1000.0000 " -_

1 mv 20.03% 1.000 In”

10 In" ?0.015% 10.00 mv i2 digits

100 In" ?0.015% 100.0 In" t2 digits

I " 10.005% 1.000 " 12 digits

10 " ?0.005% 10.00 " i2 digits

100 " F0.005% 100.0 " F2 digits

1000 " ?0.005% 1000 " ~2 digits

TABLE 6-3.

e.

Current Accuracy Check.

Fuse Check.

1.
Select lOOOn!A range.

a).

b). Measure resistance between input terminals,

using ohmmeter (F).

t2 digits

36 1174

1.01

”

1.01 v 1 MO 1

1.01 v 100 ul 10 "A iO.,O25% 10.00 UA

1.01 v 10 KG 100 !A 10.025% 100.0 UA
SO”rce (D)

settinp

10 MO

100 n.4 iO.O25% 100.0 XIA

UA

?0.025% 1.000 u*

1mA lrl!A

10 InA 10 mA ?0.02% 10.00 mA

100 mA 100 * ?0.02% 100.0 InA

1000 mA 1000 mA ?0.02% 1000 ti

**see Specifications for temperature coefficient for *c currelIt.

2. Accuracy Verification.
connect Resismnce source (E) in series

a).

wirh Voltage source (B) to farm a current Bo”r’c‘3

(for lO”A, loo”*, l&4, lO!lA, an* 100u. ranges).

b). set Voltage source (8) to 0.000000” and

Resistance source (E) to on.

Connect "Current Source" to Model 160B

c).

input.

d). Select Im" range on rhe Model 160B.

e). Adjust zero on the Model 160B for a i.OOOm"

display.

Select lOti range on the Model 160B.

f).

6). Verify the lOllA, lOOnA, lpA, lO"A, and
lOO"A ranges using tile source settings given in
Table 6-5.

NOTE

Voltage source (8) must be set lam" high to
compensaee for the Model 1608 "input drop"
at full-range.

?0.02%

6-4.
ing adjustments should be performed when any speci­fication has been determined to be out of tolcrancc.
For checking the Model 1608 to its maximum publislied
specificaclms, the Performance Verification pracr­dures given in Section 6-3 should he used.
taining the Model 160B on a six-month recalibration
cycle, Tables 6-8, 6-9, and 6-K should be used. The
"Tolerance an Reading" given in Tables 6-8, 6-9, and
6-10 is adjusted to allow for time drift- of critical
components, and also fhe effects of humidiry.
6-8, 6-9, and 6-10 also give the probable component
to be investigated if a range does not meet spccifi­cations after the Adjustment Procedure has been con>­pleted.

The Model 16OB factory-calibration is at a

level that will aSSUre all specifications are

met for a period of 12 months after shipment

from the factory.

tion, a six-month re-cd cycle is recommended
since component tolerance drift may prevent re­calibration to stringent factory-cnlibraci""

levels witbut component replacement.

lawfng calibrarion procedure uses levels that
will .¶ssure that the instrument meets puhlishcd
specifications for a six month period wichouc
requiring componenC changes.
should be performed under laboratory candi-

cions of approximately 25-C and lees than 50%

relative humidity.

1.000 mA

.4D.NSmENT/CALIBRATION PR”CE”“KE. The follow-

For main-

Tables

IMPORTANT

For subsequent recalibrn-

me fal-

Adjusrmenrs

Verify that the ImA, lomA, lOOmA, and 1000

1).

m&t ranges are within the eokxances given in Table

6-5.

0875

a. HO" to open Instrument.

over so that the bottom cover is facing up. Loose"

Turn the Hodcl l6OB

METALCAL

MC-212 -

METALCAL

MC-213 -

INSERT 26090A

2 REQUIRED

TOP COVER

26545C

FRONT PANEL

262WC

MOOIF;;KE;OTTOM

24446

as717

38

FIGURE 29.

HAiDLE
257290

Top and Boccam Cover Assembly.

1277

Kecommended Test Equiment for Calibration

Item

I ““ltmrter, oigita1

Description

Minimum Specification

10omv @ 0.015%

1v @ 0.01%
.J
K Voltage Divider

Voltage source 1” @ 0.005%

1O:l @ 0.005% ISI bZLA,lOK

100”:1 @ 0.025%

b. Power Supply Check.

he power supply voltages

can be checked with Voltmeter (I) from Table 6-6.

1. +5” Regulated Supply.

Check the Line Voltage

Switches (at rear of instrument) to see if they are

set correctly.
respect to IDput LO.

Measure the voltage at TP202 with

The voltage should be +5”,
55% ii, the “LINE” mode of operation, and also in
the “CHG” and “B,W modes of operation if batteries

are installed.

2.

-1ZV

Regulated Supply.

Check the Line “olt-

age Switches (at rear Of instrument) eo see if they
are set correctly. Measure the voltage at TP201

“it,, respect to Input LO.

-12”, 25% in the “LINE” mode of

me vo1cage should be

operation, and also

in the “CBG” and “BAT” modes of operation if bat-

teries are installed.

3. Baecery Check.

C.

How To Calibrate the msrrumenr.

See Section 6-3a.

For best ac-

curacy, the Model 1608 should be calibrated with the

Model 1609 Cal. Cover Accessory or an equivalent.

‘The instrument should be allowed to stabilize for
approximately l/2 hour after the Cal. Cover is put
in place.

It is important that the calibration se­quence be followed exactly, because the ad,uatments
are interrelated and dependent on prior calibration
SCepS.

Manufacturer

Model

nata Precision 2540Rl

Fluke

345,

NOTE

Apply a +lm” signal to the Node1 lb”13 inpii~.

d).
e). Adjust Display Zero (K136) for a rcadin~ UL

+Ol.” at the Model 1608 display.

f). Apply a -Irn” signal.

Adjust Recrifier Zero CR1351 for ii rending

d,

of -01.0 at the Model 160” display.

NOTE

DC “oitage Calibration.

d.

1. Voltage Zero and Offset Current Zero Adjust-

ment.

Select h” range.

a).
b). Place a dmrr (low-thermal copper) across

the input terminals.

ccmnect “oltmeter (I) to the Model 160B

c:).

Analog Output.

d). Adjust front panel Zero Control (R114) for

a reading of t”.?m” at Voltmeter (I).

e). remove the short acrosis the Model 1608 in-

put terminals.

f). Adjust Offset Current Zero (R121) for a

reading

af A20m” at

Voltmeter (I).

1174

3. +OC Cal. and -DC Cal. AdJustment.
Change Divider (K) setting to 0.1 ratio.

a).

t,pply a +lOOm” signal to the Yodel lb”,,

b).

input.

Adjust CDC Cal. (R137) for a reading of

cl.

+lOO.O at the Yodel 16011 display.

Apply a -1oomv signal.

d).

Adjust -DC Cal. (R134) for a readini: of

e).

-100.0 at the Model 1608 display.

39

MAINTENANCE

RllW

MODEL 1608

R136-

R135-

RlZl-

R137-

40

FIGURE 3". Location of Calibration Adjuetmenrs.

1174

MODEL 1608

MAINTENANCE

-1

JTP

"OHMS"

,+lOOmV

REF

2V-

UT-

I

1174

FIGURE 31.

+5V‘TO

MODEL 16028

Location of

Test

Points.

41

MAINTENANCE

MODEL 1608

e. Ohms Calibration.

lOOmV Reference Adjustment.

1.
a). Leave the Model 1608 set 0" the loom"

Range;;leave Voltage source (3 and DiYider (0
connected to the Model 1608 input.

b). See Voltage Source (J) co 0", and set

"ivider (K) to "0" output.

connect Voltmeter (I) to TPlOl (loom" Rd),

Cl.

Adjust the "1OOmV Adj." trimpot (R105) for

d).

+1oornv, i2OjJ" at Voltmeter (I).

Range

1 In" --

open

_-

+hlv 5%

I"" --

100 In"

2. Ohms Reference Accuracy Adjustment.

Apply a +200m" to the Model 1608 input.

b).

AdJust the "Ohms Ref. Accuracy" trimpot

cl.

(KllO) for +300mV, i6Ou" at Voltmeter (I).

Display Test Equipmene

AdJustment Name and

Reading oesig. Reading circuit Ilesig.

Front Panel zero

(R114)

(R121)

Display Zero (RI361

to1.0

(I)

(1)

__

Analog output
set ea 0 + .h"

Analog outpue Offset current zero
set to 0 i 2om"

-Ill!"
+I~oom"

2.5%
i.Ol%

-LOOWl" i.Ol%
short

-_

fZOOnl” ?.Ol%

100 In"
100 ln"
100 rn"

-01.0
+100.0

-100.0

100 Ill" --

100 rn” --

__ _­__
__

(1)

__

TPlOl see to lOOmV adj. (R105)

+loom" k 2011"

(1)

TPlOl set to Ohms Ref. Accuracy

l

3OOm" t 60~" CR1101

Rectifier Zero (RI351

+Ilc Cd. (R137)

-DC Cal. (R134)

42

_. - _ _ _ , . .._.. ___ . . ._..__ “.

Range

1 mv 21-112 digits

LO m” tl-l/2 digits ReSFSCOr Network 11160

100 Ill”

I, ”

10 ” il-l/2 digits Resistor Network R159

10” ”

1000 ”
*This rable is to be considered as an extension of Table 6-3.

modified “Tolerance on Reading” column shown here allows the user

to verify that tire instrument will meet published specs lor il per­iod ai 6 months.

‘Tolerance on Reading

il-l/2 digits Resistor Network KlbO
kl-l/2 digits Resistor Network RI59

11-l/2 digits Resistor Network R159
:!.l-l/2 digit.5

TABLE 6-9”.

Accuracy Check for Resistance

Principle Component Involved

ResI.sLor Network RI60

Resistor Network RL59

The

*This table Ls to be considered as an extension of Table 6-4.
modified “Tolerance on Reading” column shown here allows the user to
verify that the instrument will meet published specs for a period oi
6 months.

Accuracy Check ior Current

K-l/Z digits
12-112 digits
i2-112 digifs
12-112 digits
22-112 digits
?2-112 digits
13-l/2 digits
t3-l/2 digits

“This table is to be considered as an extension of Table 6-5. me
modified “Tolerance on Reading” column shown here allows the user to
verify that the insrrumenr will meet published specs for a period of
6 months.

**R163 may or may not be installed. See schematic 26590E.

TABLE 6-lo*.

RI45 (IMn)
K146 (look.21
11139 (IOk<:) and CR108
K140 (1!4)
R141 (1000)
RI42 (100)
Rl43 (0.9970)
R144 (0.0987Q) and R163** (201.)
R144 (0.0987Q2) and R163** (2OU)

‘The

1174

MAINTENANCE

5203

P203

III

1‘5114

e

MODEL 160B

c

44

FIGURE 33.

FlOl

CURRENT

PROTECTION

FUSE

Location Of Fuses.

1174

SECTION 7.

Instrument Model Number

a.

~~strurnenr Serial Number

b.

Part Description

C.

CirC"*t Designation (if applicable)

d.
e. Keirhlev Stock Parf Number.

REPLACEABLE PARTS

C. Model 1602B Digiml "utpuc - (26654E).

schematic describes the digital outp"t for Model

1608. Circuit designation series is "300".

This

1174

45

REPI.ACEABI.E PARTS

i’

Allen-Bradley carp.

Milwaukee, WI. 53204
hperex

Elkgrove Village, II,.

Amp 1°C.
Elizabethtown, PA.

Analog Devices, 1°C.

Cambridge, MA.

Beckman instruments, IIIC.
Fullerton, CA. 92634

Berg Electronics, Inc.

New Cumberland, PA.
Bourns, 1°C.

Riverside, CA.

Eussmann Mfg. Div.

St. Louis, MO.

Ccntralab Division

Milwaukee, WI.

Clarostat Mfg. co., 1°C

Dover, NH.
components, 1°C.

Biddeford, ME. 04005

03820

02142

92507

53201

60007

17022

17070

-

Farichild InStrNmenrS Curp.

Mountain View, CA.
General Electric company

Syracuse, NY. 13201

General Insrrument Corp.
Newark, NJ. 0,104

Hewlett-Packard
Palo Al,ea, CA.

1ntersi1, 1°C.
Cupertino, CA. 95014

IKC Division

Burlington, IA. 52601
ITT cannon ,aeceric

Santa Ana, CA.
Kdthley instruments, ~nc.

Cle"eland, OH. 44139
Littlefuse Inc.

Des Plaines, IL.
M"l‘2X

Ihurlers Grove, I,..

Motorola Semiconductor ProduCLs, Inc

Phoenix, AZ.

ti5008

94040

94304

92701

60016

6051.5

Erie 'Technological Products, Inc.
Erie, PA.

16512

National Serniconductar Corp.
Santa Clara, CA. 95051

RCA Carporatian

Comer"ille, NJ.
RCL Electronics, 1°C.

Manchester, NH. 03102
signetics Corp.

Sunnyvale, CA.
siemens corporaeion

Isdin, NJ.

Temple
cecate, CA. 92080

‘rexas Instruments, Inc.
Dalhs, TX.

Vfshay Resistor Products
Malver") PA.

08876

94086

08830

75231

19355

CAPACITORS

Cl01
CSO2

Cl03

Cl04

CSO5

Cl06

cso7

Cl08
Cl09
ClSO
Clll

Cl12

cs13
CL14
Cl15
Cl16
Cl17
Cl18
cu9
Cl20

C201
c202
C2"3

C204
C205
C206
c207

CRSOl
CR102

CF.103

CR104
CR105

ml06

CR107

CR108

2200 pF, 5oov, cerll
100 pF, lOOOV, cerr!.

0.1 !JF, 250". Wm.

0.56 UF, 50", MFC

0.01 UF, 250". MtF.

0.0022uF, ZOO", HPCb.

0.1 UF,

100 pF, 630", Poly
100 pF, 630". Poly

250", MTF.

O.OOZZpF, ZOO", MPCb.

2 "F,

SO
SO UF, ZO”, ETT
10 “F, 20”, ETT
39

39
22 ,,F. ZO”, ETT
22

39

0.1 “F, 25ov, MTF.

0.01 ,iF, zoov, My

0.01 !lF, 500", cerL3

2000 VF, 25", I?* I.

39
NOf Used.

470 “F, 50”, EAL

10

Rectifier, LA, 800”
cotnpurer Type, 75*, 75v.

Rectifier, Ih, aoov

Rectifier, IA, 800”

Rectifier, BOrnA, 125”.

Computer Type, 7id., 75v.

Not Used.

Bridge Keceifler, 4-diode, 50”. 5A.

50", MIT

pF, moo”, CerD.

)lF, 15", Epoxy
“F, 15". Epoxy

UF, 20”. CTT

pF, 15", Epoxy

UF, 15", Epoxy

...............

VP, mv, ETT ...........

...............

..........

.........

..........

...........

..........

.........

..........

..........

..........

.........

...........

.........

...........

...........

..........

..........

...........

...........

..........

..........

...........

..........

...........

..........

...........

..........

.......

..........

..........

........

.......

83125"022?>i
D&SOS
C280AEjP100K
62581A474

C64-lOOI'
C128-O.lPI
~201-0.56N

Cl78-.OlPl

625BlC

C280AE/P100K

831360‘%1101H
B31360AllOlH

6258X222

62581A205

D&100

TSD220106 C179-IW
TSD220106 C179-10'1

TD4-015-396-10 C228-39X

TD4-015-396-10
TUi-20-226-20
TD1-20-226-20
TD4-015-396-10

C28OAElPlOOK

IN4006
lN914
IN4006
lN4006
lii3595
IN914

..

FE05

c221-.002*EL
c178-".I?,
C252-1O"P

C252-1OOF

c221-.0022!,

C215-2Y

C64-101

C228-39s
C179-22n
Cl,')-22?,
C228-39x

CR201
CR202
CR203
CR204

Circuit

1277

computer Type, 75mA, 75v.
Computer ‘Type, 75mb., 15v.
Rectifier, Bridge Type, 1.5A, 4oov.
Rectifier, Bridge Type, 1.5*, 4oov.

.......

.......

1N914

lN9S4 RF-28
..
..

PF40

PF40

RF-28
RF-46

RF-46

FSOl Fuse, 3.4,

Microfuse : . . . . . .

273003

P201 Fuse,

F202

F203

F204 Fuse, SA, 250". . , . . . .

.JS”l Housing, Female, 3 pin .

5102

J103

5104

5105 Housing, Female, 10 pi".

J106
5107

3108

J109 Housing, Female, 5 pin .

JllO
.Jlll Housing, Female, 5 pin

.J112 Binding Pmt. Black.

5113 Binding Post, Red.

l/8*, 250", MB, Slo-Blo. . . . . . .

Fuse, l/BA. 25OV, 3.0, Slo-Blo. . . . , .

FUBB, IA, 250". . , . . . . . . .

CONNECTORS

. . . .

Housing, Female, 2 pin
musing. Female, 1 pin
Housing, Fanale, 5 pin

. .

. .

. .

Rousing, Female, 5 pin

Housing, Female, 5 pin .

Housing, Female, 5 pin

. . . . .

. . .

. .

. . . . .

Housing, Female, 3 pin

, .
. .

. .

. .

5114 Housing, Female, 3 pin

.I115
5116

5206
.I207

3208

Binding Post, Ked. .
Binding Post, Black.

Housing, Female, so pin. .....

Housing, Female, 10 pin. .....

Housing, Female, 2 pin ......

.
.

.

. .
. . .

. .

.
. .

.

.

.

MDL-l/B.4
MDL-l/8*
MD,.-1A
MDL-1A

-

-

65039-034

65039-035

47439

20370

20052
20370

20370
20370

65039-034

20370

65039-034

. . . .

. . . . .

20052

20052

65039-035

-

cs-270
~~-266
G-236
CS-251
CS-237
CS-251
CS-251
CS-251

CS-270
CS-251
85-60
BJ-6R
CS-270
25537A
25539A

CS-237
CS-237
CS-266

PlOl
PSO2

Male, 3-pins .
Male Pi” (2)

P103 Male Pi" (1) .
PLO4 Male Pi"

P105

PI06 blase, 4-pins

PI07
PSO8

PI09 Male Pi” (3) . .

PllO

Pill

Male, so-pins. .

Male, 5-pins
Male, 5-pins .

Male, 3-pins .

Male, It-pins .

(3) .

PI12 Nat Used . . .

PSS3 Not Used .

PI14

P201

P202

P203

P204
P205
P206

P207

P208 Male Pi"

48

Male Pi"

(2) . .

Cable Assembly to Model 16028. . .
Cable Assembly LO Display Board. .
Keceptacle* Male, 3 pins . . . ,
Line Cord, 3 conductor, 5 FT, 9 IN
Receptacle, Male, 4 pins . .

Male, a-pins . . . . .

Male, B-pins . . . . . . . . . .

(2)

. .

.

.

. .

.

.
. .

I

.

. .

.

.

. .

. .
. .

. .

. .

. .

.

.

.

.

. .

.

. .

. . . . . .

.
. .
.
. .

. .
. .
. .
.
. .

. .

. .

. .

.

.

.
.

.

.

.
.

.
. .
.

.
. .

.
. .
. .

.
. .

. .
.
.

.

.

.

.

.
.
. .
.

.

.

.

. .
. .
. .
.
.

.

. .
. *

. *

,
.

.

.

.
.
.

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . .

. . . . .

. . . . .

..,..

*239-3A

. . . . .

*2391-4A

. . . . .

. . . . .

. . . . .

CS-339-3

24249.4
24249A
24249A
CS-339-10
cs-339-4
CS-339-5
CS-339-5
X249*
CS-339-3
cs-339-4

. . . .

. . . .

24249A
26424A-2

26424A-1
CS288-3
CO-9
CS288-4
CS-339-8

CS-239-8

24249A

0976

MODEL 160B

Code

4101 PNP, lbwer Type, loW,-TO-5 case . . . . . .

Q102
Q103
Q104

Q105 PIP,

Q106

Q201 PNP, TO-106 Case.

q202 PNP, TO-106 case.

((203 PNP, TO-106 Case.

Dual “P” man, MOS FIST, TO-77 case. . . .

“N” Ctm, JFCT, R-110 case. . . . . . .

PNP, TO-106 case. . . . . . . . .

TO-106 case. . . , . . .

NPN, TO-106 Case. . . . . . .

.
.

. .

5

~

.

4204 PNP, TO-106 Case.
Q205 PNP, TO-106 case.
Q206 NPN, TO-92 case
q207 NPN, TO-92 case

KlOl

RlO2

11103
Kl"4

RI05

Kl"6

1107
RL08
R109
RllO
Rlll
K112

P.113
Rl14
R115

~116

R117
R118

It119

R120

R121

RI22

R123

R124

R125

RI26

R127

RI28

K129

R130

K131

11132

R133

R134

R135

11136
R137
K138

R139

R14"

R141

RI42

K143

IklZ, 10x, o.zsw, camp .

499kQ, ".5%, ".SW, MtF.

1,8kn, lo%, ".25%, Camp
499kn, I%, 0.12W. MCF
1!in. 0.5w. Var. . .

5.8!&, l%, 0.12w, MtF .
loon, 1%. O.lZW, MtF.
499kn, 1%, ".12W, MtF
475k", I%, O.lZW, MtF .
50kQ, ".5W, "ar

56.2kn, 1%. O.l2W, MrF.
l"okn, I%, ".12W, MC?

32.4kl1, 1%, ".12W, MtF.
5"k0, 2w, var . .
IM", l%, ".12W, MtF
56k0, lo%, 2W, Camp .
56ki2, lO%, ZW, Cow . .

22kn, IO%, 0.25W, C.mp.
3300, IO%, o.*sw, camp.
3300, lo%, 0.25W, Camp.

2k0, ".5W, Var. . . .

9.0kQ, 0.1%. 0.12W, MtF

10kn, 1%. 0.12W, MtF.

2.2Mn, lo%, 0.25W, Camp

lkrl, I"%, 0.25W, Camp

2.2M", l"%, 0.25W, Camp

5.6k", lo%, 0.25W, Camp

22kn, IO%, 0.25W. Coq.
22ki2, l"%, ".25W, Camp.

4.99kIi. 1%. 0.12W. McF.

12.lkn, I%, ".12W, MC.

Ikn, l"%, ".25W, Camp

3.3kR, 10%. O.ZSW, Cow

5000, ".SW, "ar .
l"kn, O.SW, Var .

L"kn, ".5W, "ar .
Ikn, ".SW, Var. .
Zkn, I%, ".12W, MtF .
I"kn, 0.02%. ".3W, MtF.
IkS,, ".I%, ".5W, MtF
100". 0.1%. 0.12w. MeF.
1o.on, O.l%, 5w .

0.99712, 0.1%. SW.

.

.

.

.

.

.
. .

. .

.
. .

. .
.
.

, .

.
.
.
. .

.

.

‘

. .

.

. .

.

.
. .
.

.

. .

.

.

.

.

.

.

.

.

.

.

.

.

.

.

. .

. .

. .

. .

.

.

.

. *

. .

.

.

.

. .

.

.
.

.
.
.

.

.

.

.

.

.

.

. .

.

I ,

.

. .

.

.

.

.

. .

.

. .

.

.

.

.

.

.

. .

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

. .

.

I .

.

.

.

.

.

.

.

.

. .

KC*
GENI
INTER
FAIR
FAIR
FAIR

FAIR
FAIR
FAIR
FAIR
FAIR
MOT
MOT

.

2N5416
955-004
ITE4392

2135139

TG-94 1
'TG-76
'E-66

2N514"

2N3565

2N5139

2N4355

2N4355
2N4355

2N4155

2215089
2N5089

Z-66
K-90 4
TG-90
TG-90
X-9"
'X-62
V-62

C&102-1"% R76-IK

1

VHF-1,2-T9-499K K171-499K

.

MFF-1/8-m-499X R177-499R

CB-182-10%

K76-1.8K

72Prn-1K KP97-IK

MFF-l/8-T9-5.8K R177-5.8K

.

DALE
DALE
IMLE

BECK

IRC

IRC

IRC

CLARO

IRC

.

A-”

A-8

A-B

A-B

A-B

.

“hl.E

.

.

IRC

.

A-B

.

ii-”

A-B

A-B

A-B

A-B

IRC

.

IRC

.

A-B

.

II-B

BECK

.

BECK
BECK
BECK
IRC

.

“IS”

“ALE

.

DALE

RCL
RCI.

MFF-l/8-T9-1"" RI,,-1""
MFF-l/8-T9-499K R177-499K
MFI-l/8-T9-475K R177-475K

72PMR-50K
CD,-TO-56.2K
CEh-TO-100K
CEA-TO-32.4K

73J*-s"Kn
CEA-TO- 1N!>
H&563-1"%
m-563-1"%
C-223-1"%
CB-331-10%
CB-331-10%

32991-2K

Km-5°K
R88-56.2K
WR-1"OK
R88-32.4K
RPlOB-5OK
RBIJ-1M
K3-56K
K3-56X
R76-22K
R76-1330

K76-33"

RF104-2K
MFF-l/8-9."KC R-lb&9.OK
CEA-TO-l"K<Z K88-1°K

m-222-10%
CB-102-10%
CB-225-l"%
C"-562-l"%
a-223-l"%
CB-223-10%
CEA-TO-4.99K
CEA-TO-12.1K

CB-1"2-10%
CD-332-l”%
72PNX-5""
72PMK-10K
72PMx-1°K
72PMR-1K
Cm.--TO-2K
V53-l"k0

MFP-1/2-u
MFF-l/8-10"

T5-10.0
T5-0.997

R76-2.2X

R76-1K
R76-2.2?(
R76-5.6K
R76-22K
R76-22K
H88-4.99K
R88-12.1K
R76-iK
K16-3.3K
KP97-5""
RPYI-LOK
RF'),-IOK
RP97-IK
m&l-2K
R183-1°K

K-169-N

K168-1""

R185-10."
11185-0.997

1277

REPLACEABLE PARTS

RESISTORS (Cont'd)

Mfr. Mfr. Keithley
Code

Lksig. Part NO.

MODEL 1608

R144
RI45
K146

Rl47

R148
RI49

Rl3"

R151

R152
R153
R154

RI55

R156
R157
Ii158
RI59
Rl6"
R161
RI62
R163
R201
R202
R203
R204
R205
R206
K201
R208
P.209
K210
R211
II212

R213
II214
R215
R.216
R217
R218

0.098711, 0.1%, 5W .-. .
Ma, O.l%, 0.5W, MtF. .

l"OkR, 0.1%, O.SW, XtP. .

99.9c. 0.1%. O.lZW. MtF .
Ik", o.l%, 0.12W, t&F . . .
10kn, ".l%, 0.12W, MLF. . .
lO"kn, O.l%, 0.5W, MU. . .
Pm, O.l%, ".5W, Mm. . .

l"Mn, ".l%, 0.5W. . . . .

99m, l%, lW, amp. . . . .

910m, I"%, ".SW, camp. . .

1.74!&, 12, O.l2W, M?F. .

Not Used. . . . . , .

27kn, I"%, 0.25W, Camp. .
47kn, l"%, ".25W, Camp. .

Thick Film Network, 4-pins.
Thick Film Network, 5-pins.
Thick Film Network. Goin "I
Thick Film Network; 14&n DIP.
1on, l%, O.l2W, MtF . . .

4.7kn, lo%, 0.25W, Camp . .

2.2kn. 10%. 0.25W. Cams .

Ikn,~iO%, b.25W, &mp : . .

3.3kn, lo%, 0<25W, Camp . . .

12.7k", l%, O.l2W, MLF. . . .

Ikn, l%, O.lZW, i.feF . . .
15on, 10%. 0.25w, camp. .
Ison, 10%. 0.25w, Camp. . .
1800, lO%, 0.7.5w, camp. . .

18Ol2, IO%, ".25W, camp. . . . .

18Os1, l"%, ".25W, Camp. . . . .

6."4kn, l%, O.lZW, MU. . .

4.02lcn,l%, O.l2W, MtF . .

lOk0, 10%. 0.25W, Camp. . . .

l"kR, 10%. 0.25W, Camp. , . .

40.2 ~2, 12, o.m, MCF. . . . .

Thick Film Network, Ih-pin DIP.
'Thick Film Network, 16-pin DIP.

. .
.
.

.
. .
.
. .

.
. .
.

.
. .
, .
.
, .
, .

.

.

.

. .

. .

. .

.
. .
. .

. .
. .

.
. .

.

.
. .

.

.

.
. .
. .

.

.
.

.
.
.

.

.
. .
. .

. .

.

. .

.

. .
. .
. ~

.

. .

. .

.

.

.

.

.

.

.

.

.

.

.

. .

.

. .
. .
. .

RCL
DALE
DALE

DALE
DALE
DALE
DALE
DALE
DALE
HIMEC
IRC
IRC

. . . . .

A-B
A-B
IRC
IRC
CTS
CTS

IRC
A-B
A-B
A-B

A-8

1RC
IX
A-B
A-B
A-B

A-B

t+B
IRC
IRC

A-B
A-B

IRC

CTS

CTS

TS-0.0987 R185-0.0987
MFF-l/L-T9-1M K169-1M
Mm-l/2-Y-100K R169-10°K

MFF-118-99.9
MFF-l/R-1K
MFF-l/8-1OK
MFF-l/Z-10°K
MFF-l/2-lM
HMF-1OM
A-6"-99M
CBT-l/2-910
CEA-TO-1.74K

. . . .

m-273-1"%
m-473-10%
KS"05
moo3
Special
QlXb.1
CEA-TO-10
m-4,2-10%
C&222-1"%
CB-102-IO%
C&332-10% K,6-3.3K
CEA-TO-12.7K
CEA-TO-1K
CB-151-10%
CB-151-10%
CB-ml-10%
CB-181-10%
CB-181-10%
CEA-TO-6.04K
CEA-TO-4.02x
CB-103-l"%
CB-10%10%
CEA-TO-40.2
900-6
900-7

R168-99.9
R168-1K
R168-lOK
R169-10°K
R169-IM

R174-10M
R-235-99M
R230-91"M

R88-1.74K

. . . .

K16-27K
R76-47K
TF-34
TF-35
TF-36
TF-37
R88-1"
R76-4.X
R76-2.2K
R76-IK

RBB-12.7K
R88-1K
R76-15"
R76-15"
R76-18"
K76-18"
K76-180
R88-6.04K
R88-4.0X
R76-1°K
R76-10K
R88-40.2
m-30
TF-31

SlOl

_--

5201
S202
5203

___

T201 Transformer, Power Type . .
TPlOl
TP201
TP202

50

Rotary Switch, RANGE. . . . . .

Knob, RANGE . . . . . . I . . . .

Slide Switch, "PDT, Line Voltage.
Slide Switch, "PDT, Line Voltage. .
Rotary Switch, dower Selector . . .

Knob, Power . . . . . . . . . .

Knob, ZERO. . . . . , . . . . . .

Tese Paint. . . , . . . ,

Test Point. . . .

Tesr Point. . . . . . .

SWlTCHES

Mfr.

. . . . . KI

. . . . .

. . . . . . .

. . . . c-w

. . . .

.*..... KI

. . . .

MISCELLANEO"S

....... KI .....

.......

....... KI

....... KI

KI
c-w GG35"PCDPDT

KI . . . . .

KI

KI ..... 24249.4

. . . . .

. . . . .

CG350PCDP"T SW-318

I....

,....

.....

..... 242491,

SW-373

w-33

SW-318
SW-374 1

m-37
KN-36

TR-156 1
24249A

. I

..
..

0875

1
1
2

1

1

3

“103
“104
“105

GLO6

Ul.10

REPLACEABLE PARTS

Operational Amplifier. 8-pin OIP.
Operaeionel hplifier, 8%pin, ~0-99 case.

Operational .bnplifier, 8-pin IDTF. .
Operational Amplifier, 8-pin IJIP.
Transistor Array, lit-pin DIP. .
operatj.ona1 Amplifier, &pin DIP. . .
Operational Amplifier, 8-pin UIP. .

NO1
“202

"203
"204

"206
0207
"208

.

Special
NE555”
SN7401N

.

.

SN7417X
CA,086
CA’3086

0875

REPLACEABLE PARTS

MODEL 1602B

MODEL 16028 DIGITAL OUTPUT

"300" SERIES. PC-352.

C301
C302
c303
c304
c305

CR301
CR302
CR303
CR304
CR305
CR306
CR307
CR308
CR309
CR310

5301
5302

5303 Female, 5-pins. . . . . . . . . . . . . . .

P301
P302

-_

O.l,F, 250", MF. . . . . . . . . . . . . . .

470@, lOOOV, CerD. . . . . . . . . . . . . . . .

470pF, 1000", CerD. . . . . . . . . . . . . . . .

470pF, lOOO", cerll. . . . . . . , . . . . . .

470p, lOOOV, &i-D. . . . . . . . . . . . . . .

DIODES

Rectifier, 75mA, 75v. .
Rectifier, 75mA, 75v.
Rectifier, 75mA, 75". .
Rectifier, 75mA, 75". .
*ecruier, 75mA. 75v. .
Rectifier, 75mA, 75". .
Rectifier, 75mA, 7%. .
Rectifier. 75mA, 75v. .
Rectifier, 75mA. 75v.
Rectifier, 75mA, 75v. .

Not Used. . . . . . . . . . .

Digital outpur, 37-pina . . . . . . . . . . . . . .

Cable Assembly (Custom) . . . . . . . . .

Mating connector, Digital output, 37-pins . . . .

Connector Cover (Hood for P302) . . . . . .

..............

..............

..............

..............

CO!wECTORS

TRANsIsTaks'

AMPRX C280AE/P100K

CENLB DD-471
CENLB m-471
CENIL! m-471
CENLB DD-471

TEXAS lN914
TEXAS lN914
TEXAS
TEXAS IN914
TmAS
TEXAS lN914
TEXAS IN914
TEXAS lN914
TEXAS lN914
TEXAS lN914

. . . . . . . .

Am 205209-1 c-301 1
BERG

KI
CAN
CAN DC-51x-1 cs-300

IN914
1N914

65039-040

. . . .

DC-37B

C178-O.lM 1
C64-470P 4
C64-470P
C64-47OP
C64-470P

RF-28
RF-28
RF-28

RF-28
RF-28

RF-28

RF-28

RF-28
RF-28
RF-28

. . . . .

CS-251

26424A-2

CS-302

. .

WY.

10

. .
. .
. .

. .
. .

.
. .

.

1
1

1
1

Q301
0302
6303
Q304
Q305
0306
cj307
Q308
Q309
c310
c311
C312
C313
c314
CL315
C316
c317
C318
c319

C320

52

NPN, Case TO-92 .
NPN, case To-92 .
NPN, Case TO-92 .
NPN, Case TO-92 .
NPN. Case TO-92 .
NPN, Case TO-92 ,
NPN, Case TO-92 ,
NPN, Case TO-92 ,
NPN, Case TO-92 .
NPN, Case TO-92 ,
NPN, case TO-92 .
NW, Caee TO-92 .
NEW, case TO-92 .
NPN, Case TO-92 .
NPN, Case TO-92
NPN, Case TO-92 .
NPN, Case TO-92 .
NPN, Case TO-92 .
NPN, Case TO-92 .
Net?, case TO-92 .

. . . .

. . . .

. . . .

. . . .

. . . .

. . . .

* . . *

. . . .

. . . .

. . * .

. . . .

. .

. .

. . . .

. . . .

. .

. . . .

. . .
.

.
* . . .

. . . .

. .
. .
. .
. .
. .

. .
. .
. .
. .
. .
. .
. .
.
. .
. .
. .
. .
. .
. .
. .

Mfr. Mfr.

Code lksip.

MOT 2N5087
MOT 2N5087
MOT
MOT 2N5087
MOT 2N5087
MOT 2N5087
MOT 2N5087
MOT 2N5087
MOT 2N5087
MOT 2N5087
MOT
MOT 2N5087
MOT 2N5087
MOT 2N5087
MOT
MOT 2N5087
MOT 2N5087
MOT 2N5087
MOT 2N5087
MOT 2N5087

2N5087

2N5087

2N5087

Keithley
Part NO.

'X-62
TG-62
TG-62
TG-62
Z-62 . .
TG-62
TG-62
TG-62
TG-62
'K-62
TG-62
TG-62
m-62
TG-62
TG-62

T-62
TG-62 . .
TG-62
TG-62
TG-62

-WA

20

. .

. .
. .
. .
.
. .
. .

.

. .

. .

1174

.
.

.

MODEL 1602B

REPL4CEABLE PARTS

RESISTORS

CiL-C"it
Lksig. Deecription

R301
R302

lOOkn, 1%. O.lZW, MtP . . . . . . . . . . . . .

lOkn, 10%. 0.25W, Camp. . . , . . . . . . , . . .

R303 Thick Film Network. . . . . . . . . . . . . . . . . KI

R304 Thick Film Network. . . . . . . . . . . . . . . . . .

R305 Thick Film Network. . . . . . . , . . . . . . . . KI

R306 Thick Film Network. . . . . . . . . . . . . . . . . KI

Mfr.

Code

Mfr.

&sip,.

IRC CEA-TO-LOOkn

A-B CB-103-10%

. . . . . TF-39

KI

. . . . w-39

. . . . w-39

. . . v-39

R307 lOkn, lo%, 0.25W, Coy,. . . . . . . . . . . . . . . . A-B CB-103-la%

R308 LOkn, 10%. 0.25W, Camp. . . . . . . . , . . . . A-B CB-103-10%

R309 lOkR, 10%. 0.25W, Camp. . . . . . . , . . . . . . A-B CB-103-10%

R310 10k0, 10%. 0.25W, Corn,,. . . . . . . . . . . A-B CB-LO3-10%

circuit

"301~
Ino2

"303

u304

II305

U306
u307
U308
"309
u310
"311
"312
"313
II314
"315

"316
u317
U318

u319

"320

Hex Inverter. 16-pin DIP. . . .

Quad &input NOR, 14-pin DIP. . . . . .

Quad 2-inpue NOR, 14-pin DIP. . . . . .

Quad Z-input NOR, 14-pin DIP. . . . , .

Dual 4-Input NOR, 14-pin DIP. . . . .

Thing circuit, 8-pin DIP . . . , . .

Quad Z-input NAND, 14-pin DIP . . . . .

Dual 'TV Type, Flip-Flop, 14-pin DIP. .
Dual "D"

Type,

Flip-Flop, Ill-pin DIP. .
Quad Clacked "D" Latch, 16-pin DIP. , .
Quad Clocked "D" Latch. 16-pin DIP.
Quad Clocked "D" Latch, L6-pin DIP. . .

Hex Buffer, 16-pin DIP. . . . . . . . .

Quad 2-inpue NOR, 14-pin DIP. . . . . .

Quad Z-input NOR, 14-pin DIP. . . . . ,

Quad 2-input

NOR.

14-pin DIP. . . . . .

Quad t-input NOR, 14-pin DIP. . . . .

quad z-input NOR, 14-pin DIP. I . . .

Quad Z-input NAND, 14-pin DIP . . . .

Quad Z-input NAND, 14-pin DIP . . . . .

. .
. .
. .
. .

. .
. .
. .

. .
. .
. .
. .
. .

. *
. .
. .

.
. .

. .

. .

. .

. .

. .

.

.

. .

. .

I .

. .

I .

. .

,

. .

< .

. .

. .

.

.

. .

. .

Mfr.
Code

RCA
RCA
RCA
RCA
RCA
SIG

RCA
RCA
RCA
RCA
RCA
RCA
RCA
RCA
RCA
RCA

RCA

RCA
RCA

Mfr. i(eithley

oesig. Part No.

CD4049.u IC-106

CD400LAE IC-108

CD4001AE IC-108
CD4001AE IC-108
CD4002AE
NE555" IC-71
CD401LA.C K-102

CD4013.a IC-103
CD4013AE IC-103
CD4042AE IC-104
CD4042.w
CD4042AE IC-LO4
CD405OAF IC-107
CD4001AE IC-108
CD4001AE IC-108
CD4001AE IC-108
CD4001AE
CD4001AE
CD401u.E IC-LO2
CD401u.E IC-102

Keichley
Part No.

RBB-LOOK
R76-LOK

R76-LOK
k76-LOK
R76-LOK
K76-LOK

LIZ-105

IC-104

IC-108
IC-108

LlLYA

1
5
4

.
.

1174

MODEL 1608

KEITHLEY PART NO. IC- 24 KEITHLEY PART NO. IC-47

KEITHLEY PART NO. IC - 53

13

2

11

w

KEITHLEY PART NO. IC -60

10 9 8

u

-93

54

FIGURE 34. Case Ourline - Integrated Circuits

1174

KEITHLEY PART NO. IC-71

.

1234

lilxl

KEITHLEY PART NO. IC-77

)i’:i.

5

0

4

0

KEITHLEY PART NO. IC-97

KEITHLEY PART NO. IC-99

FIGURE 35.

case Outline - Integrated Circuits

KEITHLEY PART NO. IC-100

KEITHLEY PART NO. IC-101

JEDEC TO-116

KEITHLEY PART NO. IC-102

KEITHLEY PART NO. IC-103

56

FIGURE 36.

Case Outline - Integrated Circuita.

1174

KEITHLEY PART NO. IC-104

KEITHLEY PART NO. IC-105

KEITHLEY PART NO. IC-106

KEITHLEY PART NO. IC-107

1174

57

REPLACEABLE PARTS

KEITHLEY PART NO. IC-108

KEITHLEY PART NO. TG-94

TO- 77

LEAD DESIG. TO-5

&) fpj$

TO-5

LEAD DESIG. TO-106

LEAD DESIG. TO-92

C

KEITHLEY PART NO. TG-77

58

FIGURE 38.

case Outline - Transistors.

1174

TF-30

TF-3

1

1174

FIGURE 39.

TF-35

Case Outline - TXick Film Networks.

59

KEITHLEY PART NO. TF-36

P’“rmrq

KEITHLEY PART NO. TF-37

mlmm

KEITHLEY PART NO. TF-39

F2

R2

Rl

RY

T2

CN

GND

-12v
+5v

FY
Fl
TO

i44

OP

COMPONENTS l.OC.4TED ON PC-349

c*rcuit Location
oesig.

Cl01
Cl02

Cl03
Cl04

Code

F-5
F-4
6-l

G-2
a05 G-l
Cl06
Cl07

cm8
Cl09

H-2

F-l

E-l

E-l

Cl10 E-2
Cl11

F-2

Cl12 F-3
Cl13 E-3
Cl14

E-4

Cl15 c-3
Cl16 C-4
Cl17
Cl18

C-4

C-4
Cl19 c-4
Cl20

C201

E-5

8-6
C202 c-7
c203 B-4
C204 B-2
C206 B-1
C207

C-3
CR101 F-5

CR102 F-5
CR103 G-2
CR104

F-2

CR105 E-3

CR106

C-3
CR108 5-6

CR201

o-7
CR202 C-7

CR203 B-3
CR204 c-2

FL01 J-5

F201 A-7

F202 A-7
5201 O-8

5202 H-7

PlOl G-2

P102
i-103
P104
P105
I'106
P107
P108
P109
PllO
Pill
P114

P203
P205
P206
P207
P208

dlO2
q103
Q104
Q105
qlO6

i202
Q203
q204
q205
(1206

Q207

RlOl
RIO2
RI03
RI04

R106
R107
RI08
RI09
RllO
Rlll

K112

R113

R114
R115

R116
Rlll

Location

CC’&

J-4
5-3
H-2
ii-5
J-5
C-2
G-4
G-4
F-3

F-3
B-4

A-8
h-8

G-8
G-8
c-4

E-4
E-2
E-2
o-2
F-6

E-5

B-6
G-6
G-6
G-6
G-6

C-6

c-7
F-4

E-5
F-5

o-5

D-5

E-5

D-5

F-3

F-4

F-4

F-3

E-5

E-5

J-1

F-3

H-2

G-2

CirC”it
tlesig. Code

RI18

R119

P.120
R121
R.122

R123

R124
R125
R126
R127
R128
R129
RI30
R131
R132
R133
RI34
RI35

R136
RI37
RI38

RI39

R140

R141

R142

RI43
R144
R145

P.146

RI47

R148

R149

R150

RI51

RI52

R153

R154

R155

RI57

R158

R159

R160

RI61

R162

R163

R201
R202
It203
R204

Location

F-2
F-l

E-2
"-1
D-1

E-l
F-3
F-3

E-3

E-2

E-3

E-3
o-2
D-2

C-6

E-6

D-4

D-2

E-4
o-4
E-6
H-4
"-5
J-5
H-5
H-5
H-5
5-4
5-4
G-4

G-4

F-4

G-5
G-5
G-5
G-5

F-5

C-5

D-6

C-5

5-Z

F-2

D-3

o-3

H-6

o-7

C-6
C-7
C-7

R205

R206
R208
R209
K210

R211

R212
R213
R214
R215
R216
K217
F.218

SlOl
S201

s202

5203
T201
TPlOl

TP201

TP202
"101

"102
"103

"104

"105
"106
UlO7
"108
"109

UllO

"201

lJ202

U203
u204

0205

U206

U207

"208

VP.101

"RI02

C-8
o-7
H-7
J-7
J-7
J-6
B-6
C-6
C-8
11-8
C-6
E-7
F-6

A-5
A-6
H-8

B-4
F-6
c-3

8-6
E-5

E-4
"-2
E-3

E-4

L-l-3
o-3
o-5
D-5
c-5

"-7

C-7

E-6
D-7
G-7

F-7

B-5

c-2

c-5

c-3

62

0875

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