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USEFUL INFORMATION FOR USERS OF TEKTRONIX INSTRUMENTS
NUMBER 3 6 PRINTED IN U.5.A FEBRUARY 1966
(Unipolar Transistors)
by Nelson Hibbs, Instructor
Tektronix Product Manufacturing Training Departmenf
At lasf w e have eulzat a ~ ~ l o z t t~ ~a s
o t F E T is a single-junction wbjority-cczrrir~ As with conventional tr;insistors, which
backward vacztu~il tube-a p-clza~zlrcl tlevice while the n-p-n and 1)-n-p transistors are represented by two types of devices
F E T . In tlzis device, electron cztrregzt a r e double-junction ~ili~~oriiy-carrier devices. (n-1)-n and p-n-p), tlie FET is also repre-
goes f r o m draitz (plate) t o sozr~cc F E T manufacturers have settled on a sented by two types of tlcvices. These a r e
(cathode). new series of names for the three basic designated tlie n-channel and the p-channel
leads of this device; so, once again we en- types of devices (see Figure 2 ) .
The Field Effect Transistor ( F E T ) is ;L counter a cl~angein terminology. Figure 1
T h e electron in "n" rnaterial has a faster
compar;itively new device whose operation compares an F E T , a convention;d transistor
differs radically from the more familiar mobility th:m the hole in "p" material.
and the familiar vacuum-tube triode to s h o ~ v
n-p-n and p-n-p types of transistors. T h e Thus, the n-p-n transistor has :i faster
this change in basic-lead terminology.
~iiol)ilityt11:~n the p-11-p transistor and conse-
quently a higher f requency response. A
similar condition exists with the new FET's.
T h e 11-channel F E T promises a greater fre-
quency response than the p-channel device.
FET
8 "ITTER
TRANSISTOR
CATHODE
TRIODE
This does not mean that the p-channel device
is not being tnanufactured.
T h e F E T is a single-junction tlevice made
Figure 1. Comparison of basic lead terminology of FET's, transistors, and vacuum tubes.
up with the Source-to-Drain material (the
majority-carrier path) doped in either the
"n" o r the "p" direction and with the Gate
material doped in tlie opposite direction. By
applying voltage s o a s to oppose the major-
ity carriers in the channel ( a negative volt-
age applied to the gate opposes electron flow
in n-channel material-a positive voltage
I N-CHANNEL
FET
I -CHANNEL
FET
opposes hole flow in p-channel material) the
device is back biased. Under these condi-
Figure 2. Comparison of an n-channel FET and a p-channel FET. tions, the n-channel o r p-c1i;unnel material
becon~es a constrictive layer of dielectric
VD vD "D material past \\.Iiich majority carriers must
flow : ~ n dcan thus be controlled. See Figure
3.
F o r a given vollage setting between the
gate :md the source (bias, if you will), the
F E T rapidly reaches a point of saturation
in the source-to-drain majority-carrier path.
This region of the curve gives the F E T an
effective R,, approaching infinity. This is
\vliere an increase in drain voltage (VD)
docs not result in an increase in drain cur-
Figure 3. Illustration of how the voltage applied as back-bias can control the flow of current in
an n-channel FET. rent ( I D ) . T h i s area of the curve is spoken
THE FET T R A
Figure 6. Comparison of an FET and a Unijunction transistor.
Operational g,, = g,,, ( a t zero bias) into the n material between the emitter and
r 3 base # 1 thus reducing the ohmic resistance
of the contact. T h e FET operates with a
voltage-driven gate and the resultant back-
biased junction with the field restricting the
Now, with a truly representative g,,, avail- majority-carrier flow through the body of
able, one can closely predict the voltage the device. Tlie F E T , like a vacuum tube,
gain of the tlevice in a circuit by using the is a nortnally "ON" device and n ~ u s t be
l'entotle A , formula : turned " O F F . Conversely, the unijunction
Figure 4. A chart of VD vs ID curves of on
.A, = operational g,,, x RI,. transistor is :I normally " O F F device (as a
FET showing the pinch off region and Ohmic
region at different values of bias voltage. result of the ohmic contacts) and must be
Noting that the input to the device is a turned "ON" by the signal a t the emitter-
bacli-biased diode, one can see that it offers two totally different theories of operation.
a high input impedance and that this haclc-
hinsed junction will show a capacitative T o summarize the properties and charae-
effect from gate-to-source and from source- teristics of tlie F E T :
to-drain. T h e latter also gives a miller A. Input Impedance :
effect. Note also, that the input-impedance
\\.ill decrease with increasing frequencies :it 1. T h e F E T is a high-input impedance
device, the input terminal is essen-
tially looking into a reverse-biased
which the product becomes compa-
'"fCcs junction.
sable to tlie input resistance. Also, the gain- 2. Tlle FET has input capacitance that
band\\itltli product will be approximatel) : varies inversely with VW (bias)
See Figure 7.
Gain Bandwidth B. Mode of operation
Again, s i ~ n i l a rto the vacuum tuhe pentode 1. T h e F E T is a voltage-co~itrolled
This dictates the usual coinpromise bet wee^^ tlevice just a s a vacuum tube pentode.
VD (VOLTS)
gain m 11:~ndwidth when using this tlevice.
d 2. T h e F E T has a very, very high R,,
Figure 5. A chart of the VI, vs In curves of Tlie F E T shoultl not lx confusetl with [lie (R,,) cli:~racteristic similar to a
another FET showing Zener-knee breakdown of \ - : ~ u u mtube pentode.
Gate-to-Drain back-biased diode. An exten- Vnijuiiction Transistor. Tlie tlieory of oper-
sion of the curves shown in Figure 4 would ation is totally different, ;dtIiough :\t first 3. T h e F E T has a consistently non-
reveal a similar tendency of this FET to ava- glance, tlie unijunction trat~sistor loolis ;\I- linear g,,, characteristic.
lanche at some certain VD voltage. most like an 11-c1i:mncl F E T . See Figure 6
for a comparison. C. Output 111ipctlance :
of as the "Pinch-Off Region". See Figure T h e unijunction transistor operates ns a 1. Tlie F E T is a high-output imped:mce
4. The area t o the side of this (where :ln current-driven tlevice with a forword-hic~scri tlevice (current source). However,
increase in VD results in an incl-e:w in junction of 1)-to-n m:~terial injecting holes cl~fferent means of manufacturing
ID-close to the graph a s i s ) is termed the
"Ohmic Region".
A study of the VD vs ID curves (see
Figure 5 ) shows that with a given load
line, the resultant transfer curve is non-
linear. This non-linearity is relative to tlie
deviation in the resistance represented in the
majority-carrier path a s controlled 11) the
biasing voltage. T h e best "g,,," occurs under
zero bias conditions and the forward voltage
at which saturation of this path occurs is
called V, (pinch-of f voltage). V, is counted
as a characteristic of the individual device.
Thus, in order t o find tlie active g,,, a t a
bias different than zero, w e must multiply
the zero-bias g,,, by the factor one minus Figure 8. Plot showing leakage current from
the ratio of gate voltage-to-pinch-ofi volt- -
Source - to - Gate (Isco) and Drain to - Gate
Figure 7. Variation of Source-to-Gate and (IDGO) against temperature under zero bias
age raised to the two-thirds power. Drain-to-Gate capacitance with voltage. conditions.
may result in relatively low ratings tection against thermal run away. This Sweep set to N P N (for 11-channel F E T ' s )
of t h i s characteristic in comparison statement is not wholly true in the case of or P N P ( f o r p-cha~~nel E T ' s ) . The
F
with t h e vacuum tube pentode. M O S (hfetal-Oxide-Insulatetf) FET's. P O L A R I T Y control of the Base Step
Generator should be set to M I N U S for n-
Another noteworthy characteristic of The M O S FET's separate the gate and channel and P L U S for p-channel FET's.
FET's is t h e i r built-in protection against channel with a layer of intrinsic material.
thermal run away. Because the input is a As temperature increases on this device, the F E T ' s that require more than 2.4 volts to
back- biased diode, the thermal - sensitive channel apparently increases also as it starts drive them to cut off-and the great major-
backward current (leakage current) flo\vs to include some of the insulating layer into ity are in this categorjr-will require that a
from both t h e source-to-gate ( 1 s ~ )and the main channel. The M O S F E T reacts 1 I&, 1% resistor be connected between
drain-to-gate (Inco). Plotting this linear more to changes in temperature than the the B A S E ( G A T E ) and E M I T T E R
current against temperature under zero bias regular FET's even though they do a\va> ( S O U R C E ) binding posts on the test panel
conditions of the other element gives two with leakage currents in the gate circuit. of the Type 575. This, in order to convert
straight line projections as shown in Figure the B A S E current, as indicated by the
\Vith standard FET's, leakage currents in
8. STEP S E L E C T O R switch in MA, to Gate
the gate lead have been reduced to the Vcs voltage in volts. Thus, 1 mA per
This increase in leakage current in the neighborhood of 0.001 to 0.0001 niA and step into 1 k a gives 1 volt/step and twelve
gate junction has a resistive effect on the this can be tolerated where instability of 11, steps at 1 tnA per step can give up to 12
majority-carrier path resulting in a lower with temperature change cannot. volts-ample in most instances to drive any
saturation current for a given bias voltage.
Characteristic curves of F E T ' s can be F E T to cut off.
For a g r a p h of this action under zero bias
conditions, and with the forward voltage displayed on a Type 575 Transistor-Curve The four waveforms represented in Fig-
froni the d r a i n to the source set at 50 volts, Tracer. The E M I T T E R - G R O U N D ures 10, 11, 12, and 13 were obtained in this
see Figure 9 ( a ) . A cross graph of g,,, and ( S O U R C E - G R O U N D ) mode is used with manner. The F E T used in these tests was
output resistance plotted against temperature the P O L A R I T Y control of the Collector an Amelco U-1346 field effect transistor.
is shown in Figure 9 ( b ) . The conlbination
tal) = 2 V/cm, ID (vertical) = 1 mA/cm. Figure 1 1 . Drain current vs Gate Source Volt-
age (ID vs Vcs with VDS constant). Vcs (hor-
izontal)= 0.5 V/cm, l ~ s s(vertical) = 1 mA/
cm.
Figure 9. ( a ) Graph of saturation current
under zero b i a s conditions and with the forward
voltage from Drain-to-Source set at 5 0 volts.
( b ) Cross g r a p h of g, and output resistance
plotted ogainst temperature.
of these t w o reactions to temperature is
Such that a s temperature goes up, g,e goes
down and R, (counterpart of R, in vacuum
tubes) goes up. In other words, as the gate
starts to lose control of the drain current, a
greater portion of the actual drain current (horizontal) = 0.5 vlcm, lnss (vertical) =
will be passed on to the load resistor thus 2 mA/cm. Center vertical graticule line is zero
tending to lllaintaill the s;lme of bias. .Negative bias to left, positive bias to Figure 13. Drain curves showing avalanche
right of center line. Crowding of markers on (breakover ot the Gote-to-Collector Zener
voltage at t h e output. This is what we mean Knee). Vcs (horizontal) =
5 V/cm, l ~ s s(ver-
right hand side is due to gate drawing cur-
when we s a y that F E T ' s have built-in pro- tical)= 0.5 rnA/cm.
T e n films produced by Tektronix, Inc. contained in square waves a r e harmonically electronic computer and comn~unication
h a v e been certified as education films by related. T h e film demonstrates the basic systems.
the U . S . Information Service. These films use of the square wave generator and oscil-
"Thevenin's Theorem" . . . A 12-minute
a r e available on free loan a s an aid to loscope antl resulting information obtained
hlack antl white sound film. Presents a
companies engaged in educational o r train- f r o m distortions. I t discusses risetime antl
simplified approach to solving a n electronic
ing programs f o r their employees; or, if its importance in testing nlodern high speed
circuit which would otherwise involve com-
preferred, the films may be purchased. electronic equipment. Suitable for audi-
plex mathematics.
ences with at least a basic knowledge of
Interested persons should contact their electrical theory. "Solving the Unbalanced Bridge . . . A
local Tektronix Field Office, Field Engi- 17-minute black and white sound film.
neer, Field Representative o r Distributor. "Transmission Lines" . . . A 23-minute Normally a solution to a n unbalanced bridge
blaclc and white sound filni. Discusses the problem requires considerable matlieinatics
Listed below a r e the film titles, along
iuntlamentals of transmission lines. Ani- involving three simultaneous equations. This
with a brief review of the film:
mated drawings illustrate how electrical lecture film shows and explains how simply
" T h e Oscilloscope D r a w s a Graph" . . . energy is transmitted along a line. A n this can be acco~nplished using Thevenin's
A 20-minute color film in sound. T h e film oscilloscope shows how reflections can oc- Tlieorp and Ohm's law.
cur in a line. Characteristic impedance, the
explains that the oscilloscope display is "Triode Plate Characteristics . . . A
usually in the f o r m of a graph, and dc- importance of proper terminations, line
16-minute black and white sound filtn. Dis-
scribes how to read o r interpret the dis- losses, time delay, and velocity factor a r e
cusses plate characteristics of a typical tri-
play. also discussed.
ode (6DJ8) showing how the three basic
tube characteristics, amplification factor,
" T h e Cathode-Ray Tube, Window to "Timc and Quantity" . . . A 27-minute
plate resistance, antl transconductance, may
Electronics" . . . A 35-minute color film blaclc antl white filni in sound. Discusses
be determined from a set of plate curves.
in sound with animated seouences. This the measurement of time and quantity from
I t also plots a load line and shows how to
film explains in simple terms how a cathode billions of years to billionths of a second.
determine the gain of a simple aniplifier
r a y tube worlis. I t depicts the heart of the Slio\vs the importance of the oscilloscope
from these curves. I n addition a continu-
oscilloscope, the cathode ray tube, a s it is as the basic means of making accurate
ous display of the curves of a tube under
used in radar, sonar and manv other elec- measurcnients of very small segments of
actual operating conditions is shown on the
tronic systems, including computers. T h e time.
Type 570 Characteristic Curve Tracer, a
film also sliows the step-by-step manufac- special-purpose Tektronix oscilloscope.
t u r i n g proceqs of cathode ray tubes at Teli- "The Oscilloscope, \\/hat I t Is-\\'hat It
tronix, from the forming of metal "gun" Does" . . . A nine-minute color sound film. "Ceramics and Electronics" . . . A 22-
parts t o the final testing of completed tubes. Presents a non-teclu~ical explanation of tlie minute color filni with sound. Shows the
oscilloscope antl its uses. Stresses tlie im- importance of ceramic elements in the
" T h e Square \\lave" . . . A 25-minute portance of the instrument a s a measuring electronic intlustries antl stresses the appli-
black and wliite sound filni. Discusses tlie tool in electronic ;ind other fields. Oscillo- cation of ceramic insulating strips and otlier
theory of square waves, employed in com- scopes measure physical data in relation ceramic parts in oscilloscopes. I t also shows
puters and many other electronic devices; to sm;dl :umounts of time. T h e y ;me used the complete manufacturing process, in-
usually, in the f o r m of coded information. in research, engineering, and education, and cluding mixing of clays, firing, and glaz-
Anin~a!etl drawings show how sine waves in production testing and maintenance of ing, at Tektronix.
I n the October, 1965 issue of Service "Current Measurements a t Nanosecond measurements at n;tnosecond speeds
Scope t ~ v o typographical errors involving Speeds" is the title of an article written
Author of the article is Murlan R. Kauf-
part numbers, slipped by your editor. Both by a Telitronix engineer and published in
e r r o r s occurrcd in the article "Type M the octoher, 1065 issue of ELECTRONIC man, Design Engineer with the Digital
Four-Trace Plug-In Unit-Channels A, R, DESIGN NE\VS, ~ 1 , ~ ( ~ the ~
i Instrument group a t Tektronix, Inc. ~
~ ~ ~ Re- ~ ~
C, and D : Crosstalk". T h e part number problems encountered when attelllptillg to prints of the article a r e available. Con-
listed as 283-0050-00 should have read 213- measure nanosecond and sub-nanosecond tact your local Tektronix Field Office,
000.3-00; ;end tlie part number listed as 210- current pulses. I t describes the use o f a Field Engineer, Field Representative o r
0001-00 sliould have read 210-0201-00. current transformer f o r accurate current Ilistributor.
CRT MESH FILTER AND RFI DUST COVERS FOR OSCILLO- TEST POINTS FOR B PLUS
SCOPES
Tektronix engineers have come up with
a new C R T light filter and R F I shield
that is unique. This new C R T Mesh Light
Filter and R F I Shield is a metal screen
of sub-visible mesh with the surface treated
for extremely low reflectance. T h e screen
is tautly mounted on a metal frame. This
unique filter-shield is a direct replacement
for the e x i s t i n g graticule cover on most
Tektronix oscilloscopes. T w o exceptions
are the T y p e 422 and Type 453 Portable
Oscilloscopes. The filter-shield f o r these
Figure 2. Short pieces of bare wire installed
instruments snaps into the C R T opening os B-plus test points in the ceramic strips of
on the f r o n t panel. o Type 5 4 5 8 Oscilloscope.
The purpose of this new mesh filter-shield
is to enhance visual C R T trace-to-bacli- I,. I?. Risllel, with the Otis Air Force
ground contrast and attenuate R F I radi- Base in M:~ssacllusetts, has submitted to
ated from t h e C R T faceplate. I t accom- the Air Force :tnd to Service Scope, a
plishes these purposes very well intleed. Figure 1. New dust cover for Tektronix oscil- "do-it-yourself" modification that you may
The curtailment of external atnhient ligllt loscopes shown on a Type 545B Oscilloscope. want t o adopt.
reflections is highly efficient. Trace-to- T h e suggestion involves installing short
b:tclwhere it provides :in ability to view low- quests, me have designed and now 11:ive in slots in Tclintensity tt-aces in normal room light, o r stock (lust covers for some Tektronix oscil- plus test points. These wires provide quick
even in 1)righter-light environnients. T h e loscopes. See Figure 1. T h e covers a r e ant1 e:tsy :ttt;tcl~ing points f o r :I voltage-
metal mesh is grounded to the metal fr:lme. made of hlue vinyl material with a taffeta ~ne:tsuringproljc tip and a r e safe even \vhen
Thus, w l ~ e n the filter-sl~ield is in place on gminetl matte finish. T h e r e a r e black gin111 using the ;~llig:itor clips often employed
the oscillo~copc, a ground path from tnesh- se:uns :u-ountl the bottom, front antl back. A ~ v i t h :I volt~neter.
to-il-;lme-to-osc~llosco~)eeffectively carslei c1e:tr vinyl front allows easy itlentific;~tion \\'e tried the modification on L Type
:
a large part of the CRT-emitted R F I spec- of the oscilloscope ant1 access holes in the .%lA OsciIIoscope ( S e e Figure 2 ) . In-
trum to chassis ground Actual quantita- top pertnit the oscilloscope to be moved st;tllation can he accomplished in :t matter
tive filtering depends upon the character- \z.ith the cover in glace. T h e Telitronis of ~ninutes :ind o f f e r s no adverse effects
istics of t h e radiation :und this varies Iw- "11ug" (tr:demarIi) and the word Telitronis on the scope's operation. T h e wire pieces
tween instrument types. a r c silk screened o n the sides. need not extend more than %" above the
ceramic strip. Installed thus, tliey provide
Following 1s a list of instrunwnt types Covcrs a r e :~v;~ilablef o r the f o l l o w i ~ ~ g
instruments : :un ample length f o r the voltage-probe tip
and the p a r t numl~er of the C R T Mesh to gs:tsp, yet a r e not so long a s t o o f f e r
Light Filter and I I F I Shield tliey use: TYPE PART NUMBER :I l~intlrance in the normal maintenance
antl calibration of the oscilloscope.
TYPE PART NUMBER 6 4 7 and 5 6 0 Series 016-0067-00
\\'it11 the empl~asis toward ever more
(except 5 6 5 and 5 6 7 )
compact instruments, and the close spacing
5 0 0 Series 01 6-0068-00 of components that results, w e recognize
5 6 5 and 5 6 7 01 6-0069-00 the need for easily accessible test points.
502, 5 0 2 A , 503, 5 0 4 , 5 0 2 and 5 0 2 A 01 6-0070-00 Some of our latest instruments have just
515, 5 1 5 A , 516, 453 016-0074-00
such test points designed into them. \Ve
517A, 5 2 4 A D , 661;
expect this trend t o continue in future
422 016-0075-00
530, 5 4 0 , 5 5 0 , and (with AC/DC bat. pok.)
5 8 0 Series 378-0572-00
422 01 6-0076-00 T Y P E 529 \ \ r A V E F O R M M O N I T O R -
506, 5 6 0 Series, 527, (with AC pwr. sup. HIGH FREQUENCY RESPONSE
RM529, 6 4 7 378-0574-00 only)
Some Type 529 Waveform Monitors will
T h e C R T Mesh Light Filter and R F 1 Covers may be ordered through your show a H F (high frequency) response that
Shields may be ordered tlirougli your local local Tektronix Field Office, Field Eli- d i f f e r s tvhen using the tiionitor push-pull,
Tektronix Field Office, Field Engineer, gineer, Field Representative o r Distributor. f r o m that shown when using it single-ended.
Field Representative o r Distributor. A capacitance utlbalance between the "A"
and "B" inputs most generally causes this wiper on the last wafer of the switch antl be on the safe side, clean all graticules with
unbalance. The unbalance results in a H F ground. Use the switch frame for ground. a nrild soap and warm water applied witlr a
roll o f f of approximately 1.3 dB at 4 M H z . Step 3. Adjust C133 for best comn~o~r- soft cloth and light rubbing action.
T h i s effect becomes particularly noticeable mode rejection. You may need to readjust
when using the Type 529 in a balanced mode C269 for H F compensation. P6015 H I G H - V O L T A G E P R O B E - R E -
of operation, with the output terminated PLACEMENT O F DIELECTRIC
with a 110 or 120-ohm resistor-a practice E X T E R N A L GRATICULES-RECOM-
employed by many telephone companies. MENDED CLEANING METHOD Only fluorocarbon 114 should be used
T h e following three-step procedure will W e recotnmend the use of a mild soap, when replacing tlre dielectric in a P6015
correct the unbalance between input "A" warm water (not hot) and gentle rubbing High-Voltage Probe. This gas is sold un-
and input "B" by balancing the emitter-to- with a soft clot11 for cleaning our external der several trade names all of which include
ground capacitance of Q114 (input "A") graticules. the number 114. This number identifies
and Q214 (input "B"). W e have employed several methods in- the gas with the proper clraracteristics for
S t e p 1. From the underside of the Verti- cluding silk screening, and (only quite use in the P6015 Probe. W e supply a stnall
cal Amplifier and D C Restorer chassis recently) hot stamping, to imprint the reti- can of fluorocarbon 114 with each P6015
locate R119, a 100-olrnr potentiometer that cules on external graticules. Accurately Probe and stock additional cans for our
serves as the X5 Mag Gain adjustment. ruled reticules composed of sharply defined, customers' convenience. Tektronix Part
Fro111 R119 a bare strap runs to a 2.26 I<, consistently thin lines aid greatly in accu- Nrnnber is 252-0120-00.
% MI, 1% precision resistor in slot 11 of rately interpreting or measuring the oscillo- T h e use of fluorocarbons other than 114
t h e adjacent ceramic strip. There is also scope display. From this standpoint, there can involve a hazard. Some fluorocarbons
a red and white wire running to another is little to choose between the silk screening are contained under a pressure IIILICII higher
2.26k, % W , 1%, precision resistor in and hot stamping methods. From the stand- than that required by fluorocarbon 114.
slot 9 of this same ceramic strip. Reverse point of visibility however, the hot stamped These higher-pressure fluorocarbons can be
these two leads at the ceramic strip. This reticule offers a 10-to-1 advantage over dangerous during the disassembly of a
should put the red and white wire at slot reticules imprinted by other methods. P6015 Probe. By escaping more violently
11 and the bare strap at slot 9. However, both the paint used in silk than expected, they could damage person-
Step 2. Remove C133, a 2.8 pF, ceramic screening and the ink used in hot stamping nel and equipment.
capacitor, located on the upper side of the the reticules are soluble in Anstac and other From tlie standpoint of toxicity, fluoro-
R E S P O N S E switch. Re-inst;dl it on the solvents. T h e i r use as n cleaming ngent twill carbons offer no problem; they are not
V E R T I C A L M A G switch between the r e i n o m the ueticttle f r o m the gmticzcle! To dangerously toxic.
T Y P E 526 V E C T O R S C O P E - Q U I E T up to eight programs. The Sequencer con- I n tlie synclrronized mode of operation,
F A N MOTOR sists of two etched circuits ( a synchronizer the sum of the Type 6R1 display time and
circuit antl a counter circuit) each mounted the Type 262 display time determines the
This modification installs a lower rpnr
in its own plug-in circuit card. Installation measurement rate-up to eight measure-
f a n motor assembly for a reduction of the is simple because the Type 262 Programmer ments per second can be madc in this mode.
audible noise experienced from the original \\.as designed with the automatic sequencer
f a n motor assembly. Tlre new assembly feature in mind and provisions n~atlefor its In the triggered mode of operation, upon
is a direct replacement except for the a d d - addition later. T o install the modification, completion of a measurement tlie display
tion of a motor capacitor which requires you need only to plug the circuit c:~rdsinto is held until an external completion pulse
the drilling of two 5/32" holes in the rear their respective plug-in receptacles in the is received. U p to six measurements per
panel of the Type 526. This ~nodification Type 262. second can be made in this mode.
is applicable to Type 526 Vectorscopes,
sn's 101-909. Front panel switches, in conjunction with Order through your local Tektronix Field
Order from your local Tektronix Fieltl the Autonratic Sequencer, allow for inter- Office, Fieltl Engineer, Field Representa-
Office, Field Engineer, Fieltl Representa- rupting tlie automatic sequence in accord- tive or Distributor. Specify Tektronix P a r t
tive, or Distributor. Specify Tektronix ance with pre-established upper antl lower Number 010-0331-00.
P a r t Number 04-0412-00. limiis. Any combination of upper, middle
or lower liniits may be used.
T Y P E RM16 O S C I L L O S C O P E - S I L I - Tlre Automatic Sequencer can be syn-
chronized with data recording devices such T Y P E 180 T I M E M A R K G E N E R A T O R
CON RECTIFIERS
as printers or card punchers or with vari- A N D T Y P E 536 O S C I L L O S C O P E -
This modification replaces the selenium ous test fixtures. SILICON RECTIFIERS
rectifiers wit11 silicon rectifiers which offer
Both nranual push button antl external Two Field Modification Kits, one for
greater reliability and longer life. I t is ap-
control are retained witlr the Automatic each of the above instruments, replace
plicable to Type RM16 Oscilloscopes, sn's
Sequencer insta"ctl. sileniutn rectifiers with silicon rectifiers.
101-363. Order through your local Tek-
A maximum of three Type 262 Pro- The silicon rectifiers offer greater stability
tronix Field Office, Fieltl Engineer, Fieltl
grammers in series will handle a total of and longer life.
Representative, o r Distributor. Specify Teli-
tronix P a r t Number 010-0216-00. 24 dif fercnt measurement programs. With Order through your local Tektronix Field
an Automatic Sequencer Modification Kit Office, Field Engineer, Field Representa-
installed in each progranrn~er the entire tive or Distributor. Specify, f o r :
T Y P E 262 P R O G R A M M E R - AUTO- 24 n~easurement programs can be auto-
matically scanned. The measurement rate TYPE PART NUMBER
MATIC SEQUENCER
can be synchronized with a~lxilinry equip-
180A 040-021 4-00
This modification supplies an Automatic ment or determined by the Type 567 antl
Sequencer for the Type 262 that will scan Type 262. 536 040-021 5-00
TEKTRONIX TECHNICAL TERMINOLOGY
to the clccfro~licjargotz ztscd by Telztronix-orienfed people.
Generally, in l e a r n i n g a f o r e i g n l a n g u a g e , pressions a n d t r a d e j a r g o n will a l m o s t sure- e n d e a v o r n o t t o employ technical j a r g o n
one is e x p o s e d p r i m a r i l y t o t h e f o r l n a l ly puzzle and c o n f u s e him. V e r y probably, :md s l a n g expressions. H o w e v e r , m a n y of
mode of t h a t language. H e will probably w e in t h e U n i t e d S t a t e s a r e m o r e p r o n e t o o u r overseas readers have expressed a n
become q u i t e adept a t r e a d i n g , s p e a k i n g indulge in t h e v e r n a c u l a r t h a n o t h e r s . a m u s e d ( a n d p e r h a p s c o n f u s e d ) i n t e r e s t in
a n d w r i t i n g t h e language i n t h i s f o r m . H o w - Since Service Scope travels to o u r f r i e ~ i d s these t e r m s a n d expressions. F o r t h e i r belle-
ever, w h e n h e encounters t h e l a n g u a g e in i t s overseas, w e d o t r y t o present i t s a r t i c l e s in f i t , w e present h e r e a f e w of t h e s e e x p r e s -
informal m o d e , t h e colloquialisms, s l a n g e x - t h e f o r m a l niode of o u r l a n g u a g e . \\'e d o sion% a n d t h e i r interpretations.
AB, n. or a , , Carbon composition resistor (from Dribble-up, n., Disproportionately long 50-100% Kluge, n., A lashup, a hastily or awkwardly
AB, t r a d e m a r k of Allen-Bradley Co.). o r 90-100% response in relation to 10.50% constmcted assembly.
or 10.90% risetime usually with reference
B.A., n. o r a , , Blanking Amplifier. to the nanosecond iime domain. Essentially Kluge, v.i., To collapse or fail utterly, usually
similar to "DC Shift". violently.
Bloom v.i. T o increase in size. The CRT dis-
pliy wi'll bloom when high voltage supplies E.F., n. or a , , Emitter-follower. Kluge, v.t., To shut down (permanently), smash
go out of regulation reducing high voltage or destroy.
and increasing defle&tion sensitivity. Eyeball v.t. Originally to avoid parallax error
in b s c i l i o s c o ~ e meisurements bv lining UD Miller, n.. A Miller integrator (sawtooth gen-
B.O., n. o r a , , Blocking Oscillator. the reflectioli of the ounil of ti% r v r Y w i t h erator).
Bounce n . Scattering of electrons that strike Mono., n., A monoaccelerator CRT.
defiecti'on structures in the CRT, producing
flare (q.v.). Flare, n., Scattering of electrons in the CRT Monoaccelerator, a. o r n., (A CRT) having a
resulting in hazy light areas on the screen. single accelerating field, with no further
BlOy;by, n., Capacitive coupling through an Usuallv caused bv bounce (0.v.) or secon- acceleration of the electron beam between
off" d i o d e gate. dary k i s s i o n in ?he CRT. d i g ~ l a ; e , - ~ i a r e the deflection structure and the screen.
resulting from the beam striking the walls
Breathe, v.i., t o vary slightly in level a t a very of the CRT. (See Dag). Multi, n., Multivibrator. Pronounced "Mull-tee".
slow r h y t h m i c rate.
Garbage, n. Large amplitude noise, commonly P.D.A.. n. or a.. Post-deflection accelerator
Bump n. a short duration small-amplitude !pw-frequency noise, a s contrasted with (post deflectioi anode),^;; a ~ C R T
-eqcipped
a6erra'tion in transient reiponse, somewhat Grass" (broadband noise). with an accelerating field on the screen
wider ( i n time domain) than a wrinkle or side of the deflection plates. Some manu-
glitch (q.v.). Glitch, n., A waveform aberration consisting of facturers call this element the "Ultor".
A n t i c b a t i o n Bumo. see Dreshmt a step or transient pulse in some portion of PDA ratio: Ratio of the gun (cathode-to-de-
Termination B U G , abekration--due to a a CRT display which would be otherwise a flection-plates) to post accelerator (deflec-
slight mismatch in a reverse- (source-) ter- smooth curve o r straight line. A train of tion-plate-to-screen) voltages in a CRT.
minated delay line, appearing in time rela- two or three small glitches might be refer-
tively l o n g after the leading edge of a step red to a s a wrinkle (q.v.); a glitch of rela- Post n. A post-deflection accelerator o r a tube
function. tively long duration or smooth symmetry ;quipped with such a n acceleratdr. "10 k v
might be called a bump (q.v.). A glitch on the post" means a 10 kV potential ap-
Cap, n. o r a . , Capacrtor. ~mmediately(before o r after) associated with plied to this element. Distinguished from
the leading edge of a pulse usually carries mono-accelerator CRT design.
C.F., n. o r a., Cathode-Follower its own terminology-e.g., pre-shoot, over-
shoot, hook, etc. Preshoot or Prepulse, n., A small negative ex-
Cathode Interface. n a tuhp defect 9nCrif
cursion immediately preceding (the display
Grass, n.. Baseline noise (broadband). CF "Gar- of) a positive-going pulse, o r vice versa.
and the emissive bage".
CRT). result- Puff, n. o r a., Picofarad (pF).
ing in a n effective RC network in series Gun, n., Electron gun. That portion of a CRT
with (Dart OR the cathode. Electrical e f f r r t which generates and focuses the electron Puffer n. A small capacitor the value of which
is normal gain at very high freq"e-ncie;-.bG beam. The term does not usually include i s ' indicated in picofarahs. one-puffer.
lower g a i n a t low frequencies. Time 'con- the deflection structure. Gun voltage refers,
stants a r e in the ns-4s area, and are con- however, to the voltage from the CRT Schmitt, n. o r a., Schmitt (cathode-coupled)
siderably affected by cathode temperature. cathode to the average deflection-plate volt- multivibrator ("Schmitt Trigger").
age.
Cream, v.t., T o ruin or destroy absolutely (by Slash, v.i., To produce a streak (usually verti-
extension from pulverize). Hook, n., A time constant (stray C or dielectric cal) instead of a dot (q.v.) on the CRT for
Crunch, v.i., T o saturate. losses) in a compensated divider unrelated each sample (sampling oscilloscopes).
v.t.. T o d r i v e into saturation, o r to destroy. to the nominal component values. (From
the effect on the display of a steD function
- Slash n. A vertically elongated dot produced
D.A., n. o r a , , Distributed Amplifier. passed through such a divider.) b) s;ot motion during unblanking in pulse-
sampling instruments.
Dag., n Conductive coating usually of carbon Hooky, a , , Exhibiting o r having a tendency t o
appiied t o the inner wall; of a CRT to main: exhibit a hook (q.v.), especially of dielectric Spudger, n., Fully insulated for dressing
tain a l a r g e equipotential area. also used to materials. leads or components.
form a helical resistor arouhd the inner
walls of a CRT to maintain a specific post- Intc?rface, n., (1) The (electrical) boundary be- T.D., n. or a , , Tunnel diode (Esaki diode).
acceleration voltage gradient. From aqua- tween two pieces of related or relate-able
dag, a w a t e r suspension of carbon particles. equipment. The conditions a t the interface Tweak, v.t., To adjust (an inductor, capacitor
(typically an output-input relationship) de- or internal calibration control) very slightly.
D.C. Shift, n., Shift of DC level following a termine electrical compatibility. The inter-
step-function, over a few seconds or tenths. face conditions between plug-in and main Tweaker, n., Tool for tweaking (usually one
Similar t o Dribble-up, but in a much longer frame in an oscilloscope a r e usually stand- which fits only certain components).
time-domain. ardized for interchangeability. i.e. voltage
current, and signal levels a t 'this 'point a r i Tweak up v.t. To bring into proper adjustment
Dogbone n. o r a. Ceramic tubular capacitor made to fall within specified limits. In by tw'eakiig.
with' radial leads. computer usage, interface equipment is that
which acts as a transducer between elec- V.A., n. o r a., Vertical Amplifier.
Dot, n., A single sample presented on screen in tronic and electromechanical parallel and
pulse-sampling. Dot Transient Response serial, or machine and human communica- Wrinkle n. A short-duration small-amplitude
transient response independence from num: tions systems. abeiratibn in transient re ber of samples per display (sampling). (2) Cathode Interface (q.v.). small echo in a delay line.
by Geoffrey A. Gass
Teki-ronix, Inc.
X-2313 Tektronix Instrument-Repair Facilities: There is a fully-equipped and properly-staffed Tektronix In- 4/66
strument Repair Station near you. Ask your Field Engineer about Tektronix Instrument-Repair facilities.
O n e o i the tlesirnl~leand potentially Inore ( 2 ) T o allow direct comp:1rison hy simul-
u s e f u l features of a general purpose con- t;meous tlisplay of events happening at
v e n t i o n d oscilloscope is its :~l)ility to tlis- different times, o r of related repetitive
1'1;~y, Ilo\\-ever monlent;irily, erratic events. events olxervetl at various different points
I ~ n f o r t ~ i ~ i : l t c l y , co~lvcntionaloscilloscope
tlle in :l system o r 11y meruns of different trans-
c ; i m ~ o t nl\vays present tl,esc events in a tlriccrs.
co~ivenie~~tly-oI)'~erve(l manner. T o co11-
veniently tlispl:ty informntion for visud ( 3 ) T o retain information from very
observ;ition, ~nensurcment,:d :tnnlysis, thc slow-tnoving traces-such ;IS those from
con\~cntion;\loscilloscope requires events that lo\v repetition-rate sampling systeins o r
r c c t ~ r ill it1cntic:tl form man?. times per high-resolution spectrum :~n:ilyzers-until
second. Giveii these conditions, the tlispl;ry the entire display may Ije observetl.
i l l I 1 r i g I s e : I y r c e Erratic
e v e n t s are 1101 :~ln.:~ys :tcco~~i~notlnting
so
so :IS io repeat themselves i~~tleiinitcly n d ;~
Fig. 1. Test circuit f o r p l o t t i n g p vs I,, Vc for
S P R C T F I C .-\PPLIC.2TIOK ARE.4S NPN transistor. Differentiation Vc w h e n I is
;~llo\v the ol~scrvcr to revise o r complete
a linear ramp produces a voltage proportional
I1is cslini:ctes.
to 13. Capacitor C (ZZ0.01 C) corrects for
overshoot i n differentiator.
liecording oi r;tntlotn tr:msients is the
nmst familiar a p p l i c a t i o ~in this area, since
~
the storage oscilloscope 111ay IK left 1111-
:tttcntlcd for extended periotls ~ ~ i i t i n g he
to sistors, a polvcr ;tmplifier o r external ramp
triggered from ;tn intermittent o r r m d o m source is required to obtain the necessary
\r principal ~ n ~ r p o s c
for :I higll-speed e v c ~ ~ t\\'ithin this category of applications
. linenrity ; for PNP types, :In inverting
s t o r a g e system in :I genernl-purpose oscil- ;ire :dso tleslructivc testing o r testing- to :implifier with out put voltage s\ving caps-
loscope, then, is to Ixin