Tektronix 221 User Manual

Instrumentation

IV

Have

instrument,

Be the readout analog, digital, CRT, or hard copy,

"portable" and "performance" are now

Once upon a
of curiosity, courage, and the judicious application of
two moistened fingertips.
men, and others who
opposed to the controlled environment of a well­stocked
manageable, and accurate
need, the integrated circuit, coupled with digital
readouts and improved
welcome revolution. Oscilloscopes, function genera­tors, strip chart recorders, spectrum analyzers, as well
as vastly improved volt-ohm mijliammeters, are now

ready to
doesn't stop with these familiar items. New types of
instruments such as a portable digital thermometer,
which measures surface temperatures
cal contact, have helped
analysis into routine field checks. In fact,
perspective on
gained from a good look
and recently announced portable instruments.

New

face for an old friend

Perhaps the piece of portable instrumentation most
familiar to any engineer
(VOM). Consisting of a high-impact molded case en­closing simple
inexpensive batteries, and a large multiscale meter,
the general-purpose VOM
ized by

years,

the

probes, has

external appearance rivaled only.by Volkswagen.

But

over

the

much portable

tinues to sell more
price of $74.50),

digital readouts has been recognized. Providing a

choice of ac line or NiCad
son's model

play

plus

and null measurements.

Customers preferring a lab-style metal case and
extra-large digital readout are offered Simpson's
model

460
blanking of nonsignificant zeros and extended
life-up

Meanwhile, many other new, interesting, and com­petitive multimeters are being offered to
neering community in both digital

eties. Dana Laboratories, Inc., Irvine, Calif., for ex-

D®ssociate

time,·

remote troubleshooting consisted

But

field engineers, service-

must

work

"on

location"-as

lab--have

go

wherever the problems are. And variety

the

Simpson Electric Co.'s model

260,

maintained

constantly demanded rugged,

test

equipment.

battery

current

progress and future trends

is

but

dependable electronics, a couple of

packs, has brought a

turn

difficult and costly

at

some currently successful

the

volt-ohm milliammeter

is

probably best character-

without

260.

To

the

this

physi-

best

For

with its complement of test leads and

a popularity and continuity

37

-of

the introduction of low-cost digital displays

past

several years has changed

test

equipment. While Simpson con-

260s

than

ever

the

interpretive-free convenience of

battery

360

VOM

(at

$295) features

the

face of

(at

the

current

operation, Simp-

an

LED dis-

a small analog indicator for scanning peak

an

VOM

(at

$395), which includes

automatic

battery

to nine hours on a full charge.

the

engi-

and

analog vari-

Editor

will

in

ample, has introduced their•

tra~sa

.

the same package

~

Danameter
crystal digits as a direct challenge to established ana­log VOMs. Some key features include
larity,

for

de voltage measurements, a tough case

automatic

molded cycolac, and one year's normal use on a single
9-volt

battery.

On the market

The

price:

about

$195

complete.

a year now

is
hand-held digital probe from Hewlett-Packard, Palo
Alto, Calif. Battery-powered, pocket-sized, and com­pletely self-contained, the 970A's controls consist of
two

thumb-actuated

lever for measuring ac volts, de volts,

slidebars

and

a push-to-test

and
cuit connections are made through a ground clip and
a movable-removable probe tip. A
na plug with a clip lead can
et

for measurements requiring two clip leads. A single

mount

MOS integrated circuit handles all the

standard

in

the

auto

and polarity adjustments, settling to yield a proper

is

reading in less
gram 970A sells for

than

two seconds (typical).

$310

and will make over

measurements on a full charge of its Ni Cad battery.

Predating the

model

167

Full-scale

voltage range

•

de

capability

•

ac

capability

Full-scale

current range

•

de

capability

•

ac

capability

Full-scale

resistance range

Range

mode /

Price (single unit)

HP

970A by

auto-probe digital

lO0mV

100 V

..

l0µA

l00µA

1

10

100

10 A

lO0Q

1

10

lO0kQ

1

10

lO0MQ

digits

at

multimeter

1 V

10 V

1

kV

mA
mli
mA

1 A

kQ
kQ

MQ
MQ

least a year

Ballantine

3/24

I

A

u

manual/3 manual/3½

$195

Optional 10-A

shunt available.

·.,

with liquid

po-

the

970A, a

ohms. Cir-

bana-

probe sock-

ranging

The

200-

2000

is

the

from Keith-

Danameter

·---------·-··-

-·-

-.--

$195

;r-.

Dana

·-·--

--·--

----

-----

--

··--

-·---

-

··-••'-••·

·-···-

..

-------

----------

-----

-

-·.

IEEE

spectrum

NOVEMBER

__

.-!f

__

--

1974

_·

-

.__J

.

..,

ley Instruments Inc., Cleveland, Ohio. Physically
unique among portable multimeters, the

167
a probe-mounted display linked to the function selec­tor and probe cradle via a special cable. Auto rang­ing and autopolarity, plus push-to-test operation, con­serve

the

batteries while speeding multipoint mea-

surements. And the

167

converts

to

a typical
configuration simply by inserting the probe into the
cradle and then connecting standard
front-panel

banana

jacks (the probe's LED numerics

test

leads to the

continue to serve as the readout). Probe, case/cradle,
and alkaline battery set come complete

While

HP

and Keithley have settled on LEDs as

the

standard

readout for portable gear,

for

$375.

Data
sion, Wakefield, Mass., offers a high-intensity plasma
display on model
timeter.

The

245,

a

$295

miniature digital mul-

rechargeable batteries last about six
hours and a high-impact case protects the instrument
from everything
switching

is

but

manual,

ov_erzealous
but

LSI and CMOS circuitry

borrowing. Range

handle autopolarity and automatic zeroing.

Apparently successful with the

duction two years ago,

Data

245

since its intro-

Precision has now gone
after the lab instrument market with the basic per­formance features of
use. Introduced in August

1

4

h-digit ac-powered multimeter that, like the

the

245

packaged for benchtop

at

$325,

model

derives its accuracy from a carefully maintained +1­volt zener reference.

features

"bench"

Preci-

1450

is
245,

Contoured like a calculator and operating off
chargeable NiCad batteries,
21

offers ac and de volts, resistance, and capacitance

Data

Technology's model

measuring capability combined in a hand-held mul­timeter. Users have the choice of continuous opera-

. tion or extending battery life with a push-to-read but-

ton

..

For an extra

$10,

a push-to-read probe allows
hands-free testing while conserving battery power.
impact-resistant polycarbonate case, handy carrying
pouch

that

clips on your belt, and 0.68-cm LED read-

outs help

the

$269

model

21

perform under rough

field conditions.

But

as the popularity of Simpson's

260
analog multimeters have not fallen categorically to
the digital onslaught. Weston Instruments, Inc., New­ark, N.J.,
670,
on printed circuit boards

for

an analog

example, has recently introduced model

VOM

which can measure direct current

without

breaking connec­tions. This ac powered "in-circuit" tester uses two spe­cial dual-tip probes
results are obtained by probing the longest

for

measuring direct current. Best

or

continuous conductor available. One contact
probe senses the voltage drop on the current-carrying
conductor under

te;t.

A

differential amplifier senses

this condition and generates a bucking current until

a

it balances the voltage drop. This bucking current
proportional to the circuit current and

is

read on the

meter. Housed in a shock-resistant polycarbonate
thermoplastic case, the

670

lists

for

$249-including

re-

An

will testify,

narrowest

in

each

is

Even a modest budget
battery-powered digital multimeters currently available.
Remember, most

haps the hardest

as

a percentage

Zero stability, temperature coefficients,

Data

Precision

245

Data Technology

21

of

around $300 allows wide selection from among the many compact,

of

the manufacturers listed produce a wide variety

parameter

of

reading

to compare among competing

±

one least significant digit,

Make and Model number

Fluke

8000A

[I

II

..

-

Still

and

frequency sensitivity can

Heath

SM-4440

Hewlett-Packard

!

Single range

200µ.A

full scale

(ac and

de)

: :

!

: :

don't see the performance

DMMs

or

±

970A

*

of

digital instruments. Per-

is accuracy. Usually

a

percentage

be

~'

of

cited separately.

Keithley Simpson Weston

168 360 4442

!

•

you

need?

ii

full-scale range.

is given

I I

-

-

,anual/4

$

295

'F

1

/2

manual/31/2

$ 269

(also measures

capacitance) shunt available.

Mennie--Have

inslrurnent,

manual/3½

$ 299

will travt:I

manual/31/,

$ 250

(assembled) •Optional

auto/3

$ 310

:-

~,_:,,

~

,.,

)"J.,._~~:

~·;

.

.

1

/2

auto/3

$ 299

1

/,

manual/3

$ 295

1

/2

manual/3

$295

1

/2

fi9

''

'

Digital multimeters have un­dergone considerable
engineering" on their way to
the market. Hewlett-Packard's

970A

(A)

245

held concept, while Fluke's

8000A
buttoned" profile coupled with

a multiposition support handle

(C).
167 combines a unique
probe /readout
mounted electronics

and Data Precision's

(B)

emphasize the hand-

sports a larger

Meanwhile, Keithley's

with

"human

"push-

bench-

(D).

·1··;:r

,)!•."'

~

:;i',

.

r

'.

t1

~~--

·

60

standard

test

leads and the two-terminal current

probe set.

Looking without lugging

While compact multimeters have long been associ-

ated with every collection of portable electronic ser­vice gear, overall bulk and power requirements have
kept oscilloscopes

stranded

on

the

workbench until

relatively recently. True, battery-operated scopes
have been on
model

321
1960-but
struments

the

market

featuring

the

obvious ground loop isolation these in-

provided was certainly

battery

for some

time-Tektronix'

power was introduced in

an

advantage

that

equaled any portability they afforded.

Not

so

with

equipment

developed over

the

past

three years by Tektronix Inc., Beaverton, Oreg., Phil­ips

Test

& Measuring

N.Y., and Vu-Data Corp.,
"miniscopes" by their manufacturers, this new

"Miniscopes," such as this Tektronix model 221, are par­tricularly helpful for servicing digital equipment.

Instruments

San

Diego, Calif.

Inc., Woodbury,

Termed

test

equipment offers compactness
that

make it ideal for on-site maintenance.

Tektronix produces four such instruments in its
series of portable scopes including
211,

dual trace

the

212.

this

past

mV

/division vertical sensitivity, and 0.1-µs/division

212,

and

The latest from Tek, model

January,

features 5-MHz bandwidth,

sweep speed packaged in

and

weight advantagc,-

the

214,

a storage version

an

impact-resistant

the

single trn,·•·

221,

21Ji;

introducei'.

7.6-

by

13.2- by 22.9-cm case. An integral 1-MQ probe
shunted

loading and
weight for
a scant 1.6
$695

Also offering 5-MHz
portable
which tip

by approximately

is

always there when you need it. Total

the

221

or any of Tek's other miniscopes

kg-including

to $1075 for scopes in

unit

are Philips' PM3000/PM3010 models,

the

scales

at

29

pF

minimizes circuit

batteries! Prices range from

the

200

series.

bandwidth

1.8 kg each.

in a lightweight

The

single trace

PM3000 has a 10-m V /division vertical sensitivity and

0.3-µs/division sweep speed while the dual

trac,-,

PM3010 offers 30-m V /division vertical sensiti\·i,
coupled with 1-µs/division sweep speed. Periods
battery

operation may be easily extended from abci: ·
five hours per pack simply by exchanging spent cei:.,
for fresh ones. Philips miniscope batteries are
charged independent of scope operation with
PM9398 ac power supply
cluded as a

19.6 cm,
packaged PM3010

standard

the

PM3000 sells for

is

/battery

charger

that

accessory. Measuring 8 by 12.5

$645

while the similarly

available for $775.

n·

ttH

is

in-

b~·

A slightly larger miniscope, Vu-Data's model PS910.
delivers 20-MHz bandwidth, 10-mV /division vertical
sensitivity, and 1-µs/division sweep speed in a
package, batteries included. Vertical
trigger

inputs

are 1

MQ

pF.

The

shunted

4.5- by 21.6- by 30.5-cm PS910

by approximately

IEEE

and

spectrum

3.:2-kg

external

.is

a

single-

NOV£MBltR

47

l.974

1,1

=:·

is

·.

)

\

l

·(

l

.

"·

!

t

~

.

·1

'-1

·,

·:1

.,,

trace

instrument

Recently

larger

dual-trace

tical

bandwidth,
pedance.
however, is
cludes a

selling for $645

the

PS910

has

been joined by a

scope,

the

vertical sensitivity,

The

fastest sweep speed on

100

ns/division,

built-in

delay line

(batteries

model PS940A, with iden-

and

and

this

miniscope in-

that

allows

edge of a signal to be displayed. Self-contained lead-

acid

batteries

kg.

while external dimensions are

bring

the

PS940A's

total

approximately

by 21.6 by 30.5 cm. Exclusive of batteries, extender

cards, or

,,copes available besides those

majority are considerably larger
"portable,"

m10

might

line

other

options,

the

PS940A sells for $1095.

While there are plenty of

but

they

won't follow you

dark

be a

current

comers.

better

is

Compact

choice for field applications where

readily available.

other

battery-operated

just

mentioned,

and

heavier.

ac-powered

Frequency vs. time

Performance is
choice of portable
aids are concerned, field engineers
ther a spectrum

loscope-without

This

is

an

another
equipment.

factor

that

can

Where electronic visual

may

analyzer or a high-performance oscil-

giving up

important

battery

operation!

option, especially

concerned with analyzing complex sounds, mechani-

rnl \'ibrations, or

,.:tJi only a few-percent distortion, for example, are

,,,-i

, .. same signal in

'.

t:.,;, out

. · :.,dis.

,:,, ,able

,·01,

across its CRT.
sµonse

filters to give good
But
the display has

While

the selected

stored in a digital memory.
displayed completely every
less image on a conventional

the memory is still

sweep feature allows

cessive
per.
monics only, bypassing

input
of 15.9

,.

ures both include

easily identified with a scope.

'test

harmonics

,1

roduced

1

,\

spectrum analyzer makes

Tuning

bandwidths

Lake

over

time

the

frustration of watching a tiny

the

passes-much

As,

a result,

Other

important

impedance of 1

kg,

communications

signals. Sinusoids

But

the

frequency domain, even

can

be accounted for.

last

year,

Hewlett-Packard's

an

excellent tool for

the

components

through a 5-

of complex low-frequency

to 50-Hz range with se-

as narrow as 1 Hz,

half

an

hour

to make one full sweep

This

slow speed allows for

needed by

the

separation

instrument's

of

spectral

dot

been

offset by digital storage.

sweep

tunes

bandwidth,

time

"grass"

like a

the

sweep traces out significant har-

the

3580A

Mn

at a rate
the

This

20

consuming,

to be ignored during suc-

underbrush.

parameters

shunted

compatible

resulting

memory is read

ms. providing a flicker-

CRT.

Since

standard

by

30

and a $4575 price tag. (These last two fig-

an

optional

battery

pack.)

extra).

somewhat

input

im-

the

PS940A,

the

leading

weight to 5.9

8.9

the

They're

up

ladders or

instruments

affect your

now select ei-

to

those

by examining

the

model

the

3580A

the

re-

narrowband

components.

drift across

with

spectrum

and

updating

an

adaptive

baseline clip-

include

pF, a weight

Vibration from heavy industrial
ined for telltale

3580A

low-frequency

Operating
model

30 function

checking

harmonics

off a 9-volt

out

an ailing

is

Destructive

components, but
"Heat

an

heat

Spy," a digital

with

spectrum

generalor

quadraphonic

may
it

can't

infrared

analyzer.

transistor

provides a

hide among printed

elude the

thermometer.

equipment

Hewlett-Packard's

radio battery.

amplifier.

may

10-kHz

circuit

William

be

exam-

model

Wavetek's

sinusoid for

board

Wahl

Corp.'s

Short-order waves

Besides tracking down

and

measuring elusive volt ­ages and waveshapes, remote troubleshooting can also
mean

stimulating
a signal of known proportions. Several
tion generators are currently available

purpose, delivery

Mennie--Have

your ailing

instrument,

equipment

custom-made

will

travel

by injecting

compact

for

just

func-

this

sinusoids, ramps,

61

Capable of handling data rates
0617B logic analyzer from CPSR, Inc., displays binary
formation

on

dual 16-bit rows of LEDs.

up

to

20

MHz,

the model

in-

and square waves wherever they are needed.

The

latest

and lowest cost of several portable func­tion generators made by Wavetek,
is

the

model

30,

which can run up to eight hours

San

Diego, Calif.,

off
conventional 9-volt transistor radio battery. Three
frequency ranges provide sine, square,
outputs

from 2 Hz to

200

kHz. Open circuit
levels are approximately 1 volt rms
volt peak to peak for
cent

duty

cycle

wave

(0

to 0.5 volt low, 3 to 4.5 volts high). Weighing

less

than

a kilogram,

The

only option, a NiCad

power supply, costs

the

at

nominal

the

an

additional $25.

triangle wave, and 50-per-

TTL

levels for the square

model

30

battery

and

triangle

output

for

the

sinusoid, 1

retails for $149.95.

with recharger/

Bearing the same price, weight, and electrical spec­ifications as the Wavetek model
ble model

195

function generat6r from
tronics, Hillsboro, Oreg.
tween

the

two units are package layout and

tion of various

ated by
while some rear-panel

the

output

jacks.

195

are available off

outputs

30

is

the

The

main

differences be-

All

the

waveforms gener-

the

are employed on the

fully porta-

Exact

Elec-

the

loca-

front panel,

model 30.

For about double

the

money of a

195

with options,
Exact will sell you their battery-powered model 191.
Generating sine, square, triangle, pulse, and

waveforms from

ers

20

volts peak to

600

ohms.) Sine wave distortion

0.1

Hz to 1

peak

open circuit (

MHz,

model

is

typically 0.5 per-

10

cent (versus about 2 percent for the
Wavetek model 30).

pack and charger

is

$350.

Total

price including

Another versatile portable function generator

ramp

191

deliv-

volts into

195

or the

battery

is

the

model 5600 from Krohn-Hite, Cambridge, Mass. Both

balanced 600-ohm
are available for tapping
square, and triangle waves.
dial and four-position multiplier provide four

and

single-ended 50-ohm

the

A

single-tum, calibrated

instrument's

outputs

sine,

bands

Portable strip
serving data
lett-Packard
sion input sensitivity, and disposable pens,
ink

a

loading problems. Price

chart

for

later

model

recorders

comparison

7155A

has 0.1-mV to

for

work

on

location

and analysis. This

the basic

unit

10-volt

which
is

$985.

covering 0.002 Hz to 2 MHz. Sine wave distortion
under 0.5 percent through
3 percent to 2 MHz. Model 5600
$70

for

the

battery

kit.

100

kHz, and no more

is

priced

The

complete

at

unit

about 3.2 kg.

Hewlett-Packard also offers test oscillators (with a
battery
and frequency range. Models
from 4 Hz to 2

power option) in this approximate price, size,

209A

and 204C operate

MHz

and

from 5 Hz to 1.2 MHz, re­spectively. They deliver sine and square wave
that

can be synchronized with
battery- or ac-powered
also available from

HP

test

an

external source. A

oscillator, model

with sine wave

output
Operating frequencies are 5 Hz to 560 kHz in five
ranges with distortion less

than

1 percent in all cases.

The price: $613.

Hot, hidden, distant, or digital

Not

every remote servicing need may be satisfied

with

standard
equipment provides
such example

electronic test gear. Sometimes special

the

only practical solution. One

is

temperature

measurement.

Two new solid-state thermometers featuring digital

readout of

temperature

have been introduced by the
William Wahl Corp., Los Angeles, Calif., in recent
months. Model DHS-8E, an infrared thermometer
known as the

"Heat

Spy,"

uses a light-beam sighting
system especially suited to small areas such as elec­tronic circuits.

The

hand-held

Heat

Spy requires no
physical contact with its target, and delivers a stable
reading in approximately one second. Accuracy

while

Hew-

per

eliminate

than

$395

plus

weighs

outputs

208A,

only.

is

pre-

divi-

is

is

0.5

62

IEEE

spectrum

NOVEMBER

1974

Mobile transmitters, restricted
ments, can
5300 series measurement system.
mainframe, battery pack,
gether

be

quickly field-tested

to

form a 500-M Hz counter.

percent over the range of Oto 540°C
also available).

The

digital DHS-8E with carrying case

sells for $1595 while

to

precise frequency assign-

with

Hewlett-Packard's

As

and

illustrated above, the

functional module snap to-

(Fahrenheit

an

older analog version, model

version

HSA-8E, costs $600 less.

Wahl's
thermometer
sensors or

area of interest. Model 392 operates from

500°C, while model 700 covers

range. Accuracy is

other

new

entry

which uses a series

platinum

resistance probes to

±0.5

percent

is a digital heat-prober

of

special thermistor

just

the 0 to 100°C

at

25°C,

contact

and

-50

the

the

to

price

is $395 for either model.

Perhaps

your problem areas are hidden

rather

than

hot. Viewing awkward, inaccessible areas is made

much

simpler
American Optical,
Mass.

This

in a 61-cm flexible gooseneck sheath, with a

powered

with

the

new FS-100 Fiberscope from

Fiber

Optics Div., Southbridge,

tool consists of two parallel fiber bundles

battery-

"cold"

light,

and

a wide-angle, fixed-focus

objective lens. One fiber bundle illuminates the view-

ing area, while
the eyepiece.
duced into the area being examined.

the

other

Neither

transmits

heat

nor electricity is intro-

a crisp image to

The

FS-100

comes complete for $295.

Microprocessors are contributing to

of

many

new

instrumentation

gear is no exception. Witness

systems and portable

the

the

flexibility

widespread success
of personal scientific calculators. An even more recent
example is

powered distance
sure distances
tial

setup

Mennie--Have

Hewlett-Packard's

meter

that

up

to 1600 meters (one mile). After ini-

and

balance

instrument,

adjustments

will

travel

model 3805A battery-

can automatically mea-

to

set

the

strength

Powered
model 239 color-bar generator from Hickok Electrical In-
strument Co., Cleveland, Ohio, provides nine basic patterns
for

of
distance measurements are continuously
averaged by a built-in
displayed on
must
sured. Normally
strument

by

two 9-volt batteries

television set-up

the

infrared reference equal to the

and

alignment work.

computer

an

LED readout. An appropriate reflector

be located

at

the far end

mounted

on a tripod,

finds its primary application in outdoor

and

priced at $115, the

return

beam,

made

(microprocessor) and

of

the

line being mea-

the

$3395 in-

and

surveying work.

Widespread adoption of microprocessors provides

added convenience while presenting

many

new oppor­tunities for remote servicing problems to crop up.
Computer
bell,
held logic analyzer for
ible with
sures, stores,
LEDs arranged in two
and display
dent
sented.

Product

Pa.,

recently announced model 0617B, a

data

can

Service

rates up to

and

displays binary information on

and

just

such occasions.

20

MHz,

16

"bit"

Research Inc., Blue-

the

rows.

be arranged to present two indepen-

16-bit words, or a single 32-bit word

CPSR

claims

the

$475

unit

is valuable

hand-

Compat-

0617B mea-

The

memory

can

be pre-

for

32

de­bugging programs used in microprocessors. Most mi­croprocessors
fore completing an instruction.
clear view of logic

go

through several machine cycles be-

The

0617B permits a

statements

in

the

circuit.

Another portable logic analyzer, also of recent vin­tage, is
querque, N.Mex. Here
rows differentiate between logic
ZERO voltage levels, while a variable

µs
The

ring pulses with a random access memory
allows storage

able for monitoring
in communications channels. One such
the model

Corporation, Moorestown, N
display
machine interface (EIA RS-232C) of any

the

MS-416 Mitscope from MITS, Inc., Albu-

64

LEDs in four equal, parallel

ONE

time

to

0.2 second) determines timing relationships.

$189.50

Much

instrument

and

then

also retains one-time-occur-

continuous display.

more complex and expensive tools are avail-

and

troubleshooting binary

instrument,

601

and

a magnetic

Datascope developed by

.J

.,

provides both a CRT

tape

recording

the

at

the business

and

logic

base (0.5

that

first

data

Spectron

standard

modem. While the $7500 Datascope won't slip into
your pocket,
rectly or through a remote connection unit

it

can be connected to the

data

that

link di-

bridg­es the EIA interface and provides electrical isolation
without adding cable length or increasing electrical
loading.
tains
the cartridge may be changed
permanent

Tape

arranged in an endless loop format

25

minutes of traffic (before erasure).

at

any time to retain a

record.

Of

re-

course,

..

.)

6