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OCTOBER 1959
C O P Y R I G H T 1959 T E K T R O N I X . INC. P R I N T E D I N U. 8. A.
SAVING CONTAMINATED filter from installation and flush dirt AVOID BURNING CRT SCREENS
OSCILLOSCOPES o r grease out of filter with a stream
of hot water o r steam. T u r n i n g down the intensity before
T e k t r o n i x Field Engineer Fred Lenc- changing plug-1x1 units in Tektronix
zynski o n a call to a Nuclear Re- (2) I f load is too heavy for treatment in
(1) ahove, prepare mild soap o r deter- Oscilloscopes eliminates a n y danger of
search operation discoveretl they xvere burning the C R T screen during this
destroying Tektronix scopes that had gent solution in pan o r sink deep
enough to cover fil- operation.
become contaminated. T h e y were very
happy t o learn that Tektronix scopes ter when laid flat.
Agitate filter up and USED INSTRUMENTS WANTED
could be washed with the Kelite solution
and retrieved from the atomic junk down in this solution 1 524 o r Frank Valencic
man. A s k your Tektronis Field Engineer until grease or dirt 514 718 E. 200 St.
for details on this money saving opera- is loosened and car- Cleveland 19, Ohio
tion. ried off filter.
1 315 o r Robert Anderson
(3) Rinse filter antl 511 University of Illinois
HIGH Gm TUBES OSCILLATING IN let dry. Chicago
TYPE 570 (4) Dip or spray fil- Control Systems Lab.
ter wit11 fresh Filter Urbana, Illinois
T h e r e is a tendency for some h ~ g l iC;m Coat, o r other ap- P h o n e : E M p i r e 7-6611
tubes being tested with the T y p e 570 proved adhesive."
Characteristic-Curve Tracer to oscillate 1 511, 514 Dr. R.B. Marion,
Filter Coat should be easy to get locally; o r 515 Physicist
despite t h e use of resistor patch cords look in the Classified Section of your
and shielding with Beltlen braid. University of Maryland
phone book for R P Air Filters, o r E Z U. S. Rt. # 1
Tektronix Field E n g ~ n e e r Earl Wil- Kleen Air Filters. If you have a n y
l ~ a l n sreports considerable success in sup- College P a r k , Maryland
trouble, we can supply you from Portland
pressing these o s c ~ l l a t ~ o n through the
s 1 511 A.C. Nielsen Company
a t $1.00 per pint.
use of Ferramic cores installed on each 807 Howard Street
bare-wire lead connecting pin jack to tube CHANGING TO SlLlCON RECTIFIERS Evanston, Illinois
socket lug. Ferramic cores are the ferrite Phone H O 5-4400
material beads that can be strung on Fieltl-Rfotlificatio~~ Kits for sevcral T e k -
t r o n i s Oscilloscopes facilitate changing 1 512 Willis Smith
wire to act as suppressors to high-fre- 5449 L a Jolla H e r m o s a
from selenium to silicon rectifiers for in-
quency currents flowing in wire. Earl Ave.
creased reliability. Kits contain all neces-
says that brief test did not show that use L a Jolla, California
sary parts and instructions.
of beads could eliminate possible nced 1 310 (or H.J. Wood, Jr.
for resistor patch cords, but he was able Field-Modification Kit 040-201 . . . . . . $60
315 Garwood Development
to display curves he had not seen to date. f o r T y p e 531 serial numbers 101
512 Lab.
through 7600
f o r T y p e 535 serial numbers 101
514 P. 0 . Box 412
REACTIVATING THE CATHODES 515 L a s Cruces,
through 8627
OF STORED New Mexico
Field-llodification Kit 040-202 . . . . $60 Phone J A 4-4044
for T y p e 531 serial number 7601 and up
for T y p e 535 serial number 8628 and up
for Types RM31, 533, RR133, RM35,
2, QUESTIONS FROM THE FIELD .)
;
A cathode-ray tube that has been in
storage for some time should be "re- 541, R1I41, 543, R3I43, 545, Rh145- Q . I s the H V power supply in the 530-
activated" before being placed in service. all serial num1)ers. 540 Series scopes capable of operating
T o reactivate the cathode, operate the a slave C R T ?
C R T with 8 volts on the heater (other A. Yes, but if there is a regulation pro-
operating conditions normal) for about blem, it may be necessary to change
one hour, and follow with 24 hours of the 6AU5 screen resistor (56 K 2 W )
operation a t normal heater voltage. Dur- to a 47 K o r 39 K 2 W resistor.
ing the reactivation period the beam Q . W h a t is the frequency response of
should be positioned off the face of the P170CF and P500CF probes when
CRT. used with 545/G?
D u e to increased production capacity,
Tektronix is now able to accept large A. W e made some measurements and
SERVICING YOUR AIR FILTERS quantity orders for ceramic terminal found the Pl7OCF to be 3 d b down a t
Reliability of Tektronix Osc~lloscopesis strips. These are the same strips as are 22 mc and the PSOOCF 3 d b down a t
i improved if the washable L u n ~ a l o y air used in current production instruments: 11.7 mc.
fllter is clean. T h e filters should be in- one, hvo, and three notch strips with one- Q.I s it possible to use a 5BG o r 5 B H
spected every three o r four months, for yoke mounting, and four, seven, nine, with the 530A and 540A?
dirt content, by holding the filter up to antl eleven notch strips with two-yoke A . Yes, it is possible if other minor
the light. T h e following filter cleaning mounting. Yolies are made of nylon, changes are made. T h e 5 B G c r t is
instructions are given by the filter and are press-fit mounted to the chassis directly interchangeable with the T533
manufacturer: \vith spacers. Please consult your T e k - crt when it is used in the 531A, 533
"To Clean: tronis Fieltl Engineer for coinplete o r 535A Oscilloscopes except for the
(1) If grease o r dirt load is light, remove particulars and prices. different vertical sensitivities of the
t w o crt's. T h e vertical sensitivities T h e new anode connectors \yere designed total time needed for displaying both
are : so that they would not have to be re- main sweeps. (See note 1)
5BG 11.2 - 13.7 v/cm moved when replacing the C R T . T h e 5. Set the Delaying Sweep Delay-Time
T533 8.6 - 10.5 v/cm connector mounts on the shield and when Multiplier (Delay-Time Multiplier)*
T h e Vertical Gain Adj. in the scope the C R T is installed the brush makes to the desired delay time needed to
should have enough range to overcome contact with the C R T anode button. a r m the Main Sweep ( T i m e Base A)*
this difference. ( A l t h o u g l ~ changing If the connector is installed after the for its second sweep.
t h e gain means you will have to re- C R T is in place, the brush is apt to be- 6. Connect the + G a t e Main Sweep
t u n e the delay line and possibly the come frayed and bent resulting in a poor ( + G a t e A ) * to the Delaying Sweep
o t h e r coils in the amplifier.) connection. I t is recommended that you Trigger o r External Sweep I n (Time
T h e 5 B H crt is directly interchange- do not remove the connector from the Base R Trigger Input)* and set the
able with the T543 c r t if pins 11 and shield when installing o r tc-placing the Slope ( T i m e Base B Trigger Slope)*
12 on the 5 B H crt are jumperetl to- CRT. switch to the + + ( Int.)* position.
gether with a strap. T h e deflection , --
sensitivities are the same in 110th o f 7. Adjust the Delaying ' ~ w e e p (Time
these crt's. Base 13)* Stability and Triggering
T h e T533 and T543 crt's have nhoto- USE of TYPES 535, 535A, Level controls to trigger on the lead-
etched horizontal deflection plates to 545 and 54549 for DOUBLE SWEEPS ing edge of the main sweep +gate.
minimize flare when the sweep in the W h e n this is properly adjusted it
533 and 543 Oscilloscopes a r e used in T w o single sweeps may be obtained should be possible to get lock out
t h e 50 and 100 times magnifier posi- utilizing the principle that when the after main sweeps.
tion. Horizontal Display switch is placed in
the Main Sweep Delayed ('A Delayed *(Captions in parenthesis apply to
by B')* position, the trigger gate circuit Types 535A and 545A instruments.)
VERTICAL INTERFIELD TEST can be armed either by depressing the
MODIFICATION KIT FOR TYPE 525 TV Note 1 : T h e total delaying sweep time
Reset button o r by a pulse from the delay must be greater than the total time
WAVEFORM MONITOR pickoff circuit. T h u s a sequence can be needed for displaying both main
A modification kit w ~ t hstep-by-step in- set up \vith a short main sweep and a
sweeps, otherwise the delaying sweep
structions is now available. T o permit longer delayed sweep, such that when could be retriggered during the sec-
observation of the V E R T I C A L I N T E R - both sweeps are triggered a t the same
ond main sweep which would allow
F I E L D T E S T S I G N A L which is in- time the main s ~ v e e p will conlplete its continuous sweep operation. I n the
serted between horizontal sync pulses o n cycle antl lock out until the delayed
T y p e 535 and 545 the total delaying
t h e porch of the vertical blanking pulse sweep (througli the delay pickoff) re- sweep time is limited to 10 msec/cm.
of t h e con~positevideo signal. sets the trigger gate circuit; then the
If a total delaying s\veep time in ex-
T h e kit includes all parts, wired V I T main sweep will accept one more trig-
cess of 10 ~ n s e c / c m is required we
chassis, photos and instructions for modi- ger pulse and lock out until the Reset
suggest a K535-S1 modification kit
fying the Type 525 Oscilloscope. Also I ~ u t t o n is pressed. T h e details of this
(Tek #040-063) \vhich gives a maxi-
included are operating instructions and are as follo\vs:
mum delay sweep range of 1 sec/cm.
internal adjustment procedure with This kit is available for $40.00 in-
theory of operation. 1. Set the Horizontal Display switch cluding a new front panel. W h e n
W h e n ordering, please specify T y p e 525 to Main Slveep Nornlal (A)*. ordering please specify the instrument
Vertical Interfield T e s t Modification Kit, type antl serial number.
2. Adjust l l a i u S\veep ( T i m e Rase A ) *
T e k Number 040-171. Price $35.00.
f o r sweep time desired and adjust Note 2: This double sweep type of opera-
triggering controls to trigger in- t ~ o nis applicable to all A to Z plug-
CRT REPLACEMENT TECHNIQUE ternally on the signal to be displayed. iu units, however the T y p e C-A unit
W e have an oc- CONNECTOR
I 3. Reset the Horizontal Display switch can be used in the alternate position
casional to Main S\veep Delayed ('A De- to observe a separate single sweep
layed by B')*. each o f two signals which are tlis-
dicating trouble placed in time. T h e T y p e C-A unit
with the new 4. Set the Delaying Sweep Time/cm is switched a t the end of each main
brush-type C R T ANODE BUTTON ( T i m e Base R , Time/cm o r Delay sweep when used In the alternate posi-
anode connectors. Time)* to a setting greater than the tion.
Tektronix Instrument-Repair Facilities: T h e r e is a fully-equipped and properly-staffed Tektronix I n -
USEFUL INFORMATION FOR USERS OF TEKTRONIX INSTRUMENTS
JANUARY 1960
COFYRIEHT TEKTRONIX. INC. 1960 PRINTED I N U. 9. A.
FIELD CONVERSION OF SOME +((Captions in parenthesis apply to Types When adjusting C706 and C735 Trim-
535A and 545A instruments) mer capacitors in the 575's collector sweep
TEKTRONIX OSCILLOSCOPES circuit, be sure that the transistor adap-
to Use Type 6DJ8 Tubes ter is in place. Tektronix Field Engineer
THIS'N THAT
All type 6BQ7A electron tubes in Tek- Lee Cooper reports that the small amount
tronix T y p e 531, 535, 541, 545, RM31, Type 310 has a typical problem: of capacity introduced by the adapter re-
RM35, RM41, and RM45 may be replaced When the high voltage power supply sults in a different setting of the trim-
with their more reliable counterpart, the goes out of regulation, the vertical and mers.
type 6DJ8, provided certain precautions horizontal gain o r sensitivity is decreased. In early "R" units, some of the power
are observed. These tubes have been This has usually been caused by an opeu transistors had what appeared to be un-
substituted without making any circuit connection on the printed circuit board ~vorkmanlikesolder connections. T h e first
changes. Minor recalibration checks are and almost alxvays seems to be in the power transistors used in the "R" unit
required in some instances. In most heater connection to V701A, a 12AT7 did not have tinned leads so were very
cases better perforn~ance may be obtained, tube. Usually it turns out to be a separa- difficult to solder. Later transistors have
as \veil a s much better reliability. tion of the solder fron-. the copper strip tinned leads, and a good solder job is
I
on the printed circuit board at the tube being done.
socket. Visual inspection, of course, QUESTIONS FROM THE FIELD
shows that V701A does not light up. 1. Q . When using the very fast Polaroid?
Reports from Tektronix Field Eugi- Land film, why do some exposures
neers Geoff Gass and Marvin Crouch, give a bright haze on the picture?
iudicate fast oscillograms are being taken A. W h e n the C R T phosphors are ex-
with Agfa Isopan Record Film developed posed to ambient room light, the
for 25 minutes in D76 at 68' F. Ken absorbed energy in the phosphor
Davis in Portland informs us that de- must be given sufficient time to
veloping 26 minutes in D l 9 at 68" F., also decay. T h e new Polaroid ? Land
gives excellent results. Measurements No. 47 film, faster than Tri-X,
made by Ken indicate that at these de- can give a bright haze on the pic-
velopments, Agfa Isopan Record has a ture from the energy retained in
"Raw-stock" tubes are used as replace- writing rate about equal to that of Tri-X. the phosphor.
ments. T h e type 6DJ8 tube appears to Compeusated Probes are no longer be- 2. Q . Can the Type 110 produce both
have inherently good short-and-long-term ing adjusted to the particular instrument positive and negative pulses?
stability. Also, the operating character- with which they are shipped. Experience A. Yes. T h e operator can choose
istics are very consistent between both indicates that past practice of matching plus pulses or minus pulses from
sections and from tube to tube. I t is probes and instruments at time of ship- a plus or minus internal charging
anticipated that the need of aged and ment is not necessary o r desirable. T h e supply. (See tentative spec. sheet,
checked tubes in the several positions probe compensation should always be ad- "Pulse Polarity" knob selects plus
that now use aged and checked 6BQ7A's justed by the operator at the time he uses or minus pulses.) Pulse widths
will be eliminated with the change to a probe with an instrument. A properly I may be identical or alternately dif-
6DJ8's. compensated probe
A n instruction sheet with a tube re- is a necessity when AIRFLOW WITH SCOPEMOBILE FAN KIT
placemeut table covering this field con- accurate readings or
version is available. Address your re-
measuremeuts are
quest for these sheets to Field Communi-
cations Department, Tektronix, Inc., P. desired.
0. B o x 831, Portland 7, Oregon. Ask for Quite a few 531
FAIR-115. manuals were ship-
EXCUSE US PLEASE ped into the field
T h e article appearing in the October showing pin 6 of
issue of "Service Scope" under the title 1720 tied to 225 volts
"Use of Types 535, 535A, 545, and 515A through R32. This
for Double Sweeps" contained a typo- was a typographical
graphical error. T h e last part of step 6 error in the 531 Man-
should read: ". . . . and set the Slope uals. R32 should go
(Time Base B Trigger Slope)* switch to 350 This Several customers have requested information on the volume
the + ( + E x t . ) * position." With this cor- \Iras reported of air provided by the Scopemobile Fan Kit modification when
rection the procedure should work. I t in the number it is installed in the Type 500A Scopemobile.
did for us. range about 9000' \\'it11 the Scopemobile d r a ~ v e rin place the airflo\v is 83 c.f.m.
With the drarver removed and a panel covering the drawer open-
? Polaroid is a registered trademark of t h e Polaroid Corl~oration, ing the airflo\v is increased to 94 c.f.m. These figures are with
liue voltage at normal.
.-.
Tektronix Instrument-Repair Facilities: There is a fully-equipped and properly-staffed Tektronix l n -
strument Repair Station near you. Ask your Field Engineer about Tektronix Instrument-Repair facilities.
A- 1093
ferent. O n "external", the pulses month or two coming, however. V23. Designate this neon bulb
m a y not only have alternately dif- 7. Q . W h a t are tlie limiting factors in 1377.
ferent widths, but also different the vertical amplifier of a 545 \rith ( ) 5. Locate V24 and repeat the pro-
polarities if desired. a C unit when you overdrive the cedure with the second neon bulb,
3. Q. W h a t is the vertical response of amplifier \\.it11 a pulse, antl try to placing the neon bulb tip in the
t h e 581 a t the 3, 6, 9 antl 12 db look a t the top one-volt portion of corresponding eyelet of C28 antl
points with a sinusoidal input? the pulse which is in the order of soldering the leads to pin 7
A . Approximately: 3db down a t 100 260 volts in amplitude? I realize antl 8 of V24. Designate this neon
a differential metliotl of making bull^ 1178.
n1c
this measurement can probably be
6 db down a t 140 ( ) 6. Add the parts list to your instruc-
accon~plislied,but I am looking for
mc tion manual and add the neon
limitations in the vertical amplifier.
9 d b down a t 180 bull^ symbols to your schematics
O n e of the reasons this question
mc diagram.
arises is the fact that you can posi-
12 d b down a t
tion the top part of this pulse to
.::>v - 7, L 10
200-250 mc
tlie center of the C R T .
4 -: - 7
i S
T h e s e values are approximate. ; .3
r ..
-7- .,
%
: -,-
:7
i '
T h e roll-off is not very smooth be- A. O n e of the Staff Engineers ran a
low the 9-12 db points, and any test on this, and found a signal
small termination bump in the that filled the graticule twice, 8 cm , ---
2
vertical will give peaks and dips in in amplitude, caused some tlistor-
responses above 200 mc. and in
some cases down as low as 100 mc.
tion. H e used a square wave from
a T y p e 105. t77 $
.\
,,,
..7c
-L. a 10 ,2:.
4. Q. W h a t tubes manufactured outside CATHODE-FOLLOWER PROTECTION
*THE LEGEND IN THE INSTRUCTION MANUAL
t h e U.S. do we use in our instru- FOR TYPE 524AD OSCILLOSCOPE S I N DIAGRAM FOR THE 524AD VERTICAL AMPLI-
ments? 5001 -5899 FIER 15 INCORRECT. IT SHOWS THIS TUBE
A 5 VZ4A I N S T E A D O F VZ48.
A . 12AT7, 12AX7-Telefunken.
\\:lien the instrument is first turned
GZ34/5AR1, ECC88/6D J8, 6360,
6939, E180F/6688-Amperes
on an excessive voltage exists between USED INSTRUMENTS WANTED
the grid and cathode of the catliode-fol-
12AU7-Telefunken and Amperes 1 T y p e 532/B George Peterson
lower sections of V23 and 21. A modifi-
5. Q . W h a t shift in trace is permissible cation is recommended for all T y p e 524- T h e Aircraft Instru-
when changing the CA from a AD instruments, S / N 5001-5899. ment Co.
condition of having two traces, T w o N E 2 neon bulbs are installed King of Prussia Rd.
both centered, to tlie Added Al- I\-liich will ignite for several seconds when Ratlnor. P a .
gebraically position? the instrument is first turned on. T h i s 1 T y p e 512 o r Allen \V. K u r t z
A. Not more than 3-cm shift is allox- \\-ill hold tlie grid-to-cathode voltage to 514 International Elec-
able. This can be adjusted by a reasonably safe value until the instru- tronics hIfg. Co.
changing the vertical position and ment is warmed u p and in operation. 515 East Grand Ave.
range (R4376). These neon bulbs a r e available from your Springfield, Ohio
local electronic supply sources. 1 T y p e 514 o r Patrick Close
6. Q . Can the attenuators for the P80
Procedure: 515 Westgate Laboratories
probe be stacked to provide less
sensitivity than 5 volts/cm? Are ( ) 1. Remove the right and left side Box 63
there any larger attenuators in panels. Yellow Springs, Ohio
sight? ( ) 2. Locate V23 (6BQ7) near the cen- 1 T y p e 531 o r Rex V. Johnson
A. A t present, the attenuators for ter of the V A chassis. 535 with B 39 Newell Avenue.
t h e P8O probe cannot be stacked. ( ) 3. Locate ceramic turret near V23 o r C Plug- Haddonfield, N e w
W e are \\-orking on a 10 x attenu- on \\-Ilk11 is mounted C31. T h i s I n Unit Jersey
a t o r which has resistive and capacitor is a variable compression 1 T y p e 531 o r 0 . Kienow
capacitive characteristics similar to type which has large eyelets on 535 o r 541 5813 E . 19th Street
t h e P80 probe. W i t h this atten- both terminals. o r 545 Tucson, Arizona
uator, it will he possible to use any ( ) 4. Place the glass tip of one of the O n e of the engineers of Maico Co.
of the present attenuators, increas- new neon bulbs in the lower hole woultl like a 3" scope for his basement
i n g their attenuation ratios b y a of C31 so that the leads m a y lab. T e k , Rlinneapolis will act a s go-
factor of 10. I t will be another be soldered t o pins 7 and 8 of between.
USEFUL INFORMATION FOR USERS OF TEKTRONIX INSTRUMENTS
AUGUST 1960
CDPYRIGHT 1959 T E K T R O N I X , INC. P R I N T E D I N U. 8. A.
DOES THE SQUARE WAVE RESPONSE :athode sleeve, and a low cathode cur- is the article "Wavemeter, Oscil-
OF YOUR SCOPE LOOK LlKE THIS? -ent flow will hasten the formation of the x c o p e Measure Magnetic Field By
mpurities l a y e r . . . .in many tubes the 'aramagnetic Resonance". This informa-
ime required is less than 500 hours. ive article, which appeared in the Decem-
However, a sizable current flow through ~ e r 1959 issue of E L E C T R I C A L D E -
.he tube tends to minimize the effective ; I G N N E W S , claims an accuracy o f
'ormation of an interface layer by pene- '-0.06 percent in measuring the gap flux
trating the accumulated impurities with lensity of a magnet by the method de-
random low resistance current paths cribed in the article. A further advan-
(holes) between nickel sleeve and barium age claimed for this new technique over
oxide coating. onventional methods is the speed with
Evidently, interface will manifest itself vhich these measurements can be made.
in any instrument employing vacuum
tubes to either display o r generate fast-
rise square waves. W e can assume that TYPE 502 TRIGGER AMPLIFIER
Fig. 1 TUBE PROTECTION
since a tube in operation can form an
interface layer in less than 500 hours,
OR LlKE THIS? instruments in operation 8 hours a day H e r e is a simple modification to pro-
should be checked for evidence of this tect the T y p e 502 trigger amplifier tube
defect every 30 to 60 days, o r a t least (V24) from high amplitude signals when
every 500 hours of operation. used with external trigger input.
T o check the vertical amplifier of a n Locate R10, a 1-meg, %-watt, 1070
oscilloscope for indications of cathode in- resistor. This resistor runs from ground
terface, feed in a fast-rising square wave to a point on the T R I G G E R S E L E C -
o f about 500 kc. Set the sweep rate to T O R switch. From this point a wire strap
display several cycles. If an overshoot connects to the P L U S - M I N U S s\vitch.
o f about 1/2 microsecond time constant is Replace this strap with a 470-k, %-\I,,
apparent, some of the vertical amplifier 1070 resistor shunted by a ,001-qf, 500-v
tubes have probably developed cathode discap.
interface. For absolute proof, plug the T y p e 502's with serial numbers above
Fig. 2 oscilloscope into an ac power source with 623 do not require this change.
a variable control. An increase in the
output voltage of the power source will SUGGESTED READING
Unless the squarewave response of your increase heater voltage and reduce over-
scope resembles the waveform shown in shoot caused by cathode interface. A
Fig. 2 . . . .better keep reading! For an excellent discussion on the con-
decrease in the output voltage of the nection between band\vidth and frequency
A condition known as cathode interface power source will decrease heater voltage
can gradually develop in the vertical arn- response, composition of rise-time and
and increase overshoot due to cathode in- other details associated \\it11 square wave
plifier tubes of any oscilloscope, causing terface.
d e g e n e r a t ~ o nof medlum antl low frequen- testing, see Vol. 18, Radiation Labora-
T h e only cure for the problem caused tory Series, " V a c u u n ~ Tube Amplifiers"
cies. . . .leaving an overshoot o n the lead- by cathode interface is replacement of the
ing edge of fast-rise (2 psec o r less) ( McGra~r-Hill)
offending tubes.
squarewaves (see Fig. 1). T h e entire instrument should be check-
L o w frequency degeneration is caused ed and recalibrated at least every six
by the serles resistance (50 o h m s o r HOT SCOPE!
months. Only through periodic main-
more) of an interface layer of cheniical tenance, can the full usefulness, accuracy, 'Sektronix Field Engineer H a l Dosch
impurities that forms between cathode and dependability built into Tektronix reports lie has received \vord from Naval
sleeve and the barium oxide cathode oscilloscopes be realized. Intelligence that a Tektronix T y p e 515A
coating. Oscilloscope, S / N 3645 is missing from
Leading edge overshoot is caused from Earl Anderson
Customer Service Staff the U.S. Navy Electronics Laboratory at
the by-passing effect of the capacitance San Diego antl has apparently been
(.005fif or greater) between oxide coating Tektronix, Inc.
stolen.
and cathode sleeve. If you shoultl see this instrument,
N O T E : In a true sense, this is not a MEASURING MAGNETIC FIELDS
.P know of its whereabouts, o r have any in-
pure capacitance, as the electronic action information regarding it, contact the
within the interface la'yer (serving as the nearest office of the Naval Intelligence
dielectric) is highly complex. Department immediately.
T h e rate at which an interface layer
forms within a tube is a function of cath-
ode temperature, number of hours the TYPE 536 AMPLIFIER MODIFICATION
tube is used, average cathode current, and
the amount of impurities originally pres- A modification kit, to convert the type
ent in the cathode sleeve material. For 5894 tubes in the T y p e 536 vertical and
example, high cathode temperature, long horizontal circuits to type 6340's is avail-
hours o f operation, a high percentage oi Suggested reading for those people in- able. This conversion, which provides
impurities in the nickel used to m a k e tht terested in the measuring of magnetic improved reliability and simplifies tube
replacement, is applicable to instruments Ask your Tektronix Field Engineer for: 1 Type 515 Norm Haugen
with serial numbers below 615. Instru- or 535/CA Communitronics
ments with serial numbers above 614 Tek No. Description Price 2012 Longwood Road
have been factory converted to use the 355-043 Replacement graticule N/C West Palm Beach, Fla.
type 6340 tubes. T h e kit contains: two stud Phone: T E . 3-8320
wired tube socket mounting-plate assem- 212-507 Screw, 10-32x3/SUBHS N/C
blies, one step-by-step check-off instruc- 210-010 Lockwasher N/C 1 Type 530 John Sutherland
tion booklet with photos, schematic and Series or 2706 21st Avenue S.
parts list, all other components and hard- preferably Seattle. Wash.
ware required in the conversion. W e do not recommend the operation of 540 Series
a Tektronix Plug-In Oscilloscope with
A s k your Tektronix Field Engineer for the side panels removed. T h e fan will not
T y p e 536 VA-HA Tube Conversion Mod- 1 Type 524 James Scharman
distribute air properly to the plug-in pre- Alvarado T V Co., Inc.
ification Kit No. 040-192. amplifier area when the side panels are Albuquerque, New Mexico
not in place. Continued operation of the
OSCILLOSCOPE PHOTOGRAPHY instrument under these conditions will de- H. L. Ziegler
1 Type 514
crease tube reliability. 275 Middle Street
East Weymouth, Mass.
Sometimes 01'1 the older Type 524 in-
struments it is difficult to time the .1 1 Type 511 J i m Williams
psec/cm sweep range. Tektronix Field or 514 4424 Juniper Avenue
Engineer Hal Dosch offers this sugges- Wichita 16, Kansas
tion to correct the difficulty: Be sure the
horizontal sweep amplifier is properly 1 Type 514 E. J. Crossen
con~pensated. Then, if adjusting the vari- 81 Cherry Lane
able capacitor C231A will not bring the Levittown, Penn.
.1 psec/cm sweep into range, try reducing
or shorting out R274. This 1.5-k, j/2-w, 1 Type 514 Herbert L. Rosenblatt
10% resistor is in series with C231A. or 531 Dept. 694, Burroughs
Corp.
Great Valley Labs.
A bulletin inten USED INSTRUMENTS WANTED Paoli Penn.
to the photography of traces on the
1 Type 524 Larry Hine
cathode-ray tube of Tektronix 5-inch 1 Type 514 H . Stuart Dodge
120 Elmwood Place
oscilloscopes is available. This is a re- or 531 Reliability Dept.
Shearill, N. Y.
vised and up-dated edition of a former Burroughs Corp.
bulletin many oscilloscope users found Great Valley Labs.
helpful. Suggestions are offered and some 1 Type 310 J. M. Gottschalk
or 310A 108 Charles Drive B-2 Paoli. Penn.
of the topics discussed are: Polaroid-
Land* films, exposure guides and how to Bryn hlawr, Penn.
photograph different types of traces. USED INSTRUMENTS FOR SALE
A s k your Tektronix Field Engineer for 1 Type 541 D. A. Nina 2 Type C. W . Penque
FIP-3, "Notes on T h e Practical Photog- or 541A and Elion Instruments 511AD Sperry Products Co.
raphy of Oscilloscope Displays." CA Plug-in 701 Canal Street S/N 3690 Danbury, Conn.
Unit Hristol. Pa. and 3692
*Polaroid is a registered trademark of
the Polaroid Corporation. 1 Type 511A Larry Garcey
1 Type 515A Jack Holcomb S/N 4544 Electronic Transiston
or 503 MacLeod Instrument North Bergen, New Jersey
THIS 'N THAT Corp.
Micro-Dyne Division 1 Type 515A Gilbert Levy
Occasionally the graticule studs on a 4250 N.W. 10th Avenue S/N 2298 Semi-Con Electronics
Tektronix 5" oscilloscope work loose. Ft. Lauderdale, Fla. River Road
You can r e ~ l a c ethese with a tapped stud
- - Phone: L O . 4-8518 Edgewater, New Jersey
Tektronix Instrument-Repair Facilities: There is a fully-equipped and properly-staffed Tektronix In-
strument Repair Station near you. Ask your Field Engineer about Tektronix Instrument-Repair facilities. A-2029
USEFUL I N F O R M A T I O N FOR USERS O F TEKTRONIX INSTRUMENTS
OCTOBER 1960
C O P Y R I G H T 1959 T E K T R O N I X . INC. P R I N T E D I N U. 8. A.
VERTICAL AMPLIFIER TUBE PROBLEM ~f o r d i n a r y soltler o r t h e application o f intl t h e coriiplcted surface will b e
too m u c h heat \\.ill break tliis bond. ; m o o t h e r if you s a n d a bit bet\vcen
T h e T y p e 531A, 533, 545A, 551, a n d \\re rcconi~iientltlie use of a solder con- :oats.
555 i n s t r u m e n t s use 6 D K 6 v a c u u m tubes taining a b o u t 3% silver \vhen soldering Surface coat, t h e desira1)le type of resin
in t h e distributed-amplifier section of 311 T e l i t ~ ~ ~ii is s ~ - u ~ i l e n t s . h i s type of
n t T -or this \ v o ~ - k ,is m a d e h y several com-
t h e i r vertical-deflection circuits. M o s t solder is o i t e n uscd in printed circuitl-y ~ a n i c s . Y o u r supplier caii provide you
6 D K 6 t u b e s develop c a t h o d e interface antl slioultl b e readily available from ivith measuretl a m o u n t s of resin a n d cat-
a f t e r a f e w h u n d r e d liours of operation in y o u r local supply source. If you e s p e r - :llyst a s ivell a s a 2" inch I ~ r u s ht o a p p l y
t h e s e circuits. T e s t s m a d e a t o u r factory ience difficulty in obtaining this soltler, ; I I C coating. T h e brusli should have a
( a n d in tlie field) have s h o w n that cer- it m a y b e o r d e r e d t h r o u g h y o n r T e k t r o n i s ipecial resin-resistant glue t o hold t h e
tain commercially-available 6DK6's, wlicn Fieltl Office. A s k for Tektl-onis t i ~ ~ r n b c r hristles.
used in these circuits, develop soniewhat 251-514 Solder, Silver Bearing 1 # spool Cost of tlic resin, catalyst arid I ~ r u s ht o
less cathode-interface resistance. If y o u (3% silver). P r i c e $3.50. d o Jack's joh \vas $5.50.
a r e h a v i n g trouble with o n e of t h e above
i n s t r u m e n t s , w e s u g g e s t a call t o y o u r T l i e fan m o t o r s of m o s t T e k t r o n i s in-
local T e k t r o n i s Field Engineer. H e \vill s t r u m e n t s s l i o ~ ~ l t b e oiled 1x1-iotlically
l
b e g l a d t o help you pill-point t h e tl-ouble SILICON RECTIFIER MOD KITS
(see tlie maintenance section of y o u r
a n d s u g g e s t r e c o ~ n m e n d e dcorrective mea- instruction m a n u a l ) . A couple of drops I3clow is a partial list of t h e currently
sures. o n tlic end of a toothpick is sufficient. A available silicon rectifier field modification
good suggestion would he t o oil tlie kits. T h e s e kits replace tlie selenium
m o t o r every t i m e t h e air filter is cleaned. rectiiiers in t h e low-voltage po\ver Sup-
TYPE 5351545 DELAYING If tlic air cleaner is never cleaned, you ply of s o m e T e k t r o n i s instruments with
SWEEP-RANGE can oil t h e new m o t o r you install! t h e silicon t y p e rectifiers. T h e s e m o r e
MODIFICATION KIT reliable rectifiers give longer service arid
AN INEXPENSIVE COATING FOR tlie kits a r e designed t o be installed with
T h e s w e e p delay available in a T y p e WORK BENCH SURFACES a m i n i m u m of effort.
535 o r 545 oscilloscope can b e increased
o n e h u n d r e d fold. A nlodification t h a t
, .
J a c k 13annistcr, a 1 eliti-onis Field
E a c h kit contains a prcwirctl chassis
with silicon rectifiers mounted, stcp-by-
e x t e n d s t h e upper limits of tlie sweep llaintenance Engineer, l ~ a s sent in a sug- s t e p instructions, photos, schematic a n d
d e l a y t o 10 seconds ( u p p e r limit of origin- gestion for i m p r o v i n g t h e surface o f a p a r t s list.
al equipment is 0.1 second) is available w o r k bcncli. 1-Ie coated his bench top W e strongly rcconimend t h a t you place
in kit f o r m . T h e desirable feature of with a n epoxy resin. I n addition t o be- y o u r o r d e r for these kits tlirougli y o u r
c o n t i n u o u s calibrated a d j u s t m e n t h a s i n g easy t o I i e ~ l ) clean, t h e resin \\.cars Tcliti-onix Field Engineer. H e can apply
b e e n retained a n d a n y period of delay a\vay a t a m u c h slo\vcr rate than mason- t h e special consitlerations necessary when
f r o m 1.5 microsecond t o 10 seconds can itc a u d liceps O I I C {I-on1 g o u g i n g a hole o r d e r i n g s o m e of tlie kits antl t h u s assure
b e accurately selected. in tlie \vorli bench \vlien turning instru- y o u speedy delivery of t h e correct ltit for
T l i e modification is accomplished b y ments-especially t h e older sqnare-cor- y o u r instrument.
replacing t h e s t a n d a r d 2 ~ n i c r o s c c o ~ ~ d / c m 11ered OIleS-over.
t o 10 millisecond/cm delaying-sweep Jack first faced t h e i r o n t of his I ~ e n c h T y p e 310 Oscilloscope, all serial n u m -
r a n g e w i t h a 3 microsccond/crn t o 1 sec- with \vood t o e l i m i ~ i a t ea nietal rim a n d b e r s I)elo\\; 7141. O r d e r T e k t r o n i s T y p e
o n d / c m range. t l ~ e n put t h e resin o v e r tliis \vood also. 310 Silicon Rectifier Modification Kit,
T h i s modification applies only t o tlie T h e resin sticks ~ v e l lt o masonite, \vootl, T e k n u m b e r 040-195. Price: $30.00.
T y p e 535 a n d T y p e 545 instruments-all painted metal a n d plastic n.ood. R e s u r e
T y p e 513 Oscilloscope, all serial n u m -
serial n u m b e r s . T h e T y p e s 535A a n d t h e plastic ~ v o o dis coniplctely d r y I ~ e f o r e
bers. O r d e r T e k t r o n i s T y p e 513 Silicon
535A i n s t r u m e n t s c o m e equipped with a t h e resin is applied, o t l ~ e r \ v i s ct h e resin
Rectifier Mod Kit, T e k n u m b e r 030-211.
2 microsecond/cm t o 1 second/cm de- t e n d s t o s t a y soft o v e r it. T h e tnaterial
P r i c e : $30.00
laying-sweep range. t o be coverctl slioultl b e clean a n d free
T h e modification kit contains a wired- o i \ \ a s . All cigarette o r soldering-iron T y p c 515 o r 5 l 5 A Oscilloscopes, serial
s\vitch assenibly, step-by-step instructions, b u r n s s l ~ o u l t l b e sanded tloivn t o clean nuriibcrs b c l o ~ v 1030. 0 1 - d e r T e l i t r o n i s
photos, schematic anti p a r t s list. O r d e r tnaterial-the resin doesn't \\.ant t o stick T y p e 515/515A Silicon Rectifier 3Iod Kit,
t l ~ r o u g h o u r T e k t r o n i s Fieltl Oificc. A s k
y t o c h a r r e d si~rfaces-and a n y holes, T e