INSTRUCTION

IAi8/tA"%H DUAL TRACE AMPLIFIER

7A18

7A18

TABLE OF CONTENTS SECTION 1

SPECIFICATION lntroduction Electrical Characteristics 7A18 And Mainframe Frequency Response Environmental Characteristics Physical Characteristics

Page

OPTION INFORMATION

I- I

1-1

SECTION 6

Abbreviations and Symbols

1-3 1-3 1-3

Parts Ordering lnformation SECTION 7

SECTION 2

SECTION 3

OPERATING INSTRUCTIONS

DIAGRAMS AND CIRCUIT BOARD ILLUSTRATIONS

Installation

2-1

Front Panel Controls and Connectors

2-1

General Operating Information

2-2

Basic Applications

2-4

Symbols and Reference Designators Voltage and Waveform Conditions

CIRCUIT DESCRiPTlON SEC'TION 8 Introduction Block Diagram Description Detailed Circuit Description

SECTION 4

ELECTRICAL PARTS LIST

3-1 3-1

MECHANICAL PAR1'S LIST Mechanical Parts List Information Index of Mechanical Parts Illustrations Mechanical Parts List

3-1

MAINTENANCE

Accessories

Preventive Maintenance Troubleshooting

SECTION 5

Replacement Parts

4-3

Component Replacement

4-4

CALIBRATION Recalibration Interval

CHANGE INFORMATION

Abbreviations and symbols used i n this manual are based on 5-1

or taken directly from IEEE Standard 260 "Standard

'Test Equipment Required

5-1

Symbols for Units", MIL-STD-12B and other standards o f .

Part I -.-Performance Check

5-3

the electronics industry. Change information, if any, i s

Part I I - Adjustment

5-7

located at the rear of this manual.

REV. JUNE 1974

7A18

7A18

Change information, i f any, affecting this section will be found at the rear of the manual.

t ntroduction The 7A18 and 7A18N Dual Trace Amplifier plug-in units are designed for use with l-ektronix 7000-Series Oscilloscopes. The 7A18 and 7A18N are electrically identical except that readout encoding capabilities and an "IDENTIFY" function are provided only in the 7A18. All references made t o the 7A18 apply equally t o the 7A18N unless othewise noted. The 7A18 is a dual-channel, medium-bandwidth amplifier. Internal gain and compensation circuits are automatically switched to correspond to

the setting of the VOL-I"S/DIV switch. Channel 2 can be inverted for differential measurements. The 7A18 can be operated in any plug-in compartment of the 7000-Series Oscilloscopes.

The following electrical characteristics are valid over the stated environmental range for instruments calibrated at an ambient temperature of i - 2 0 " ~to +30°c, and after a five minute warmup unless otherwise noted.

TABLE 1-1 ELECTRICAL

i wrViDiv t o 5 VIDIV; tcrt step5 111

6

I,

Deflectran Factor Accuracy

Vrrhrri 296 with GAlN adjusted a t 0 mV/Div,

Uncalibrated

:ontinuously vat iablc between cal~brart teps; extends deflection factor tn at East 12.5 ViDiv

(VARIABLE)

GAlN

Pern-ritsadjustrrrcnt of tic:flect~nnfactor

for cdlrbrdted or>erdtiot~ wit17 all 7000set rcs uscrltuzcopes,

-

--

Frequency Respar7se Syslorn Dependent (8dtv refc~encestgnal) Upper Bandwrritlr DC {Direct) CuuplecJ

ower ljandwiclth -

7A18

Specification-7A1817AI 8N TABLE 1-1(contj Characteristic

-Information Supplemental

Performance Requiremen_t-.- - - - --

""

Maximum Input Voltage DC Coupled

!50 volts, (DC + Peak AC); AC comIonent 500 volts peak-to-peak maxinum. one kilohertz or less.

AC Coupled

j00 volts, (DC + Peak AC); AC compolent 500 volts peak-to-peak maxinum, one kilohertz or less.

Channel Isolation

50: 1 display ratio up to 50 megahertz.

Input R and C

-- -----

--

---

Resistance

Approximately 20.0 pf

Capacitance RC Product

---*-----~"." .."."-"".----,-....-*Nithin k: 1% between all deflection

Displayed No~se $00microvolts or less a t 5 mV/Div in 7000-Series Oscilloscope.

(Tangentially Measured) ".

"-

......

.,"-'"--

,"

1.1 ms or less to recover to within one livision after the removal of an overjrive signal of up to -1-75divisions or -75 divisions regardless of overdrive ;ignal duration.

Overdrive Recovery Time

"

.,..----..-..-..

~

..-"

A t least 10: 1 up t o 59 megahertz.

Common Mode Rejection Ratio DC Drift D r ~ fwith t Time (ambient temperature and line voltage constant)

1.02 divisron or less in any one minute, fter one hour warmup.

D r ~ fw r ~th Temperature (line voltage constant) - --

do more than 0.01 d~vis~on per degree C.

---

- -- - - -- -- -- "'00 picoseconds or less.

Time Delay between Channels ------- - -- -----

---

Display Modes

-

-*

Zhannel 1 only. Dual-trace, alternate between channels.

Added algebraically. Dual-trace chapped between channels. Shannel 2 only.

7A18

TABLE 2.1 (cant)

TABLE A 7A78 AND MAINFRAME

With

1500 Scr res

60 MHz

Wutl7

7400 Sas its$

50 blE4r

Refer $0s t ~ cSpecifaca!~un fw tbw il"iocidt~C1O S C I ~ ~ O S C Q ~ ~ ~

7 ABLE $3

7A18

SECTlON 2 TING INSTRUCTIONS [jolt

wrll ire forrtrtl as

E

t!ttv~^l%cli 01 ~ ! T Piilrnti?ilctl

I

Tilt; 7A18 ss caltkrratasrt arrd rr;arly f o r taw as rrcecirs:rd II cdn hi3 rn~tdiltxt9i-1 81193\;ilasirpartn$tilllI uf Tektrcrnix 7CIC)OSrrrtes n s ~ a l i o " IJ~IT ~ ; ~I**~ ~~iiaenrbd ~ ~ ~ ~ ~ ~P ~ i r /J~H~CPIJSJ \is#- ln vrrttcal b~liisavn ccrlnjlartiuxnrarl": Tn ~rsq"iail, ~ k i q t l~ f i a " iilirjrdx" a i d Iowa*rro~ll,01: SIW 7A 1;R l i v i ~ l l itiia: ~ ( i i : ~ t iojve n ~ liar k i nrad iiilly sr-as~pr-r-t 11The Irrrv~tw ~ l lIsp f l l i s i ~w11lb fhc Iron1 rrl IRc? rrwtllost OJIC ~Uieli~ ille 7A 18 ns liriiy r r r w r t i ~ tartd ~ tile i&ch d t the iraariicn left corrtcal of 1111ccticxnsolderccl ra tlrccirt board Connection made t a crr cult board w ~ t hrnterconnectlnq prri. Biiie trnt cncioses contyronerlts located on crt cirit hoard

Tfte tollowing ptefrx letters are used as referertce designiltois to rdentify components or assernblres on the cJ~agrams. Assembly, se~sdtableor tepdrrable icrtc~rtIroatcj, elir 1 Artei~u~itur, f l x c ~or i vat table Motor E3,ittrry Cdr~acrtor,fixed or variable Diode, signal or i ecttf re1 Delay l t n ~ Inciicatrng devtce tldmp) Fuse F~ltei Heat riisstpatrng devir:e (heat srnk, heat iadlator, etc ) Hcatet Crrnnectot , stationdry porrltrn Relay irlducior f ~ x e dor vartable

.

LR M Q

P R RT S T TP U

V VR Y

inrluctor/re.;tstor combinatran Meter Transistor or srlicon controlled I ectif ier Connector , r~iovablepot tron Reststor, fixed ot vai rable Thermrslur Stwttcia Trdnsforiller Tear potnt Assernbty, Inseparable or non repaft abic (rntegratd circurt, ti: \ Electroil tnbe Voltage tequldto~(retier diode, etc ) Crystal

7A18

VOLTAGE AND WAVEFORM TEST' CONDITIONS

'Sypical voltage measurements were obtained under the following conditions unless noted otherw~seon the indlvtduat d~agrams:

Voltmeter

1 YPe Input impedance Range Recommeniied type (as used for voltages on diagrams)

Non-loading digital multimeter 10 M Q 0 to 1ooa vol t s 'fektronlx 7013 D~gitalMultimeter

7B70 (A Horizontal compartment) LeveI!Slope 'Trigger~ng &'lode Coupiing Source Magnifier TimeiDiv Variable Ext Trig I n connector

Centered on positive slope P-P AUto AC Ext X1 1 ms Cal In No connection for voltage measurements. For waveforms Sig Out from osc i l loscope connected t o Ext Trig I n connector.

?A18 (left vertical compartment) DISPLAY MODE rRIGGER SOURCE CH 2 POLARITY

ALI MODE hUP

CH 1 and CH 2 VO LTSID IV COUPLING POSI^IION VARIABLE Signal Applied

10 m V DC Centered GAL I N No signal for voltage measu r e m e n t s , 40 m V square wave from oscill o s c o p e Calibrator applied t o both input connectors for waveforms.

7A16 (right vertical compartment using a 10X probe with readout coding ring. P6053 probe used for waveforms on diagrams) Polarity Bandwidth Position Coupling Variable

+UP Full Centered AC Cal In

Vert~calMode Horizontal Mode A lntens~t~ B Intensity Calibrator Volts Rate A Trigger Sotrrce B Trigger Source

Right A Optimum Counterctockw~se

40 m V I kHz Right Vert Left Vert

All voltages giver? on the diagrams are in volts. A l l currents are in milltamps Waveforms shown are actual waveform photographs taken wlth a rektronix Oscilloscope Camera System. Vertlcal deflect~onfactor shown or1 waveform IS the actual deflection factor from the probe tip. Voltages and waveforms on the diagrams (shown in blue) are not absolute and may vary between instruments because of component tolerances, Internal cal~brat~on or front panel settings. Readouts are s~mulatedIn latger than-normal type.

NOTE The spring tension of the pin sockets ensures a good connection between the circuit board and pin. Phis spring tension may be damaged by using the pin sockets as a connecting point for spring-loadedprobe tips, all(qator clips, etc.

7A18

INPUT SOURCE

PARAPMABE

SECOND

CASLODE

CASCODE

FOLLOWER

AMPLIFIER

AMPLIFIER

EMlTTER FOLLOWER

I

I I

INPUT

I

I ATTENUATORS

m

GAlN AND

) VARIABLE

COUPLIhG

CONTROLS

--

I I

r

>

SIGNAL OUTPUT

m

!

'

L

-

A

v

S30AtB DlSPLAY MODE 5 TRIGGER S 3 V R C E C-

7

* SlOOB

lNPUf SOURCE

FOLLOWER I

I IUPUT COtJPL I! IG

I I

ATTEN8J4TORS

@

TRIGGER

OUTPUT

52COY D

PARAPHASE CA5CODE AMPClFlER

LASCODE AMPLIFIER

EMITTER FOLLOWER

TRLGGER

+

)CUANNEL

TRIGGER

SWITCH

)GAlN A N D VARLABLE C O N f ROLS

-

+ 9560

Ud70

Q 580

OUTPUT

-

!

READOUT

)ENCODlNCU 9620

L 7

4 0 IDENTIFY

-L

CHANNEL

2 OUT

TIME-SLOT

lNT ERFACE

CONNECTOR

7A18

5100A

A t / G N O /DC/ DC OFFSET (SHOWN IN A C PO5lT ION)

AC GND DC

QFF5ET

CHANNEL 1 INPUT S I G N A L

TO

>=+

A1 ATTENUATOR

4210

BOARD

CHANNEL 1

CIRCUIT

CHANNEL

20 pF

1 SWITCHING

IDENTICAL T O CHANNEL

1 ABOVE

I

2 1

P R O B E COOING TO C 4 5 5 7

0

~ A ~ ~ J ~ AOIP B TIO NN 6

CHANNEL 2

ATTENUATOR

@

5% 7A18

Fig. 7-1A. Amplifier Circuit Board Assembly, Option 6.

@

7A18

CHANNEL 1 INPUT S I G N A L T O R210 XI00 ATTEM crrq

CIIB

P R O B E CODlhlG TO C R 3 5 7

CIRCUIT

CHANNEL 2 IM* 20 pF

ATTEN CIIO

CIII

CIOG t 1 0 7

CHANNEL 1

0

T-oor

ATTFN C I I ~c r r ~


B37

5237 RL4b

150K

-

C*L

UNCAL

CUANPIEC L READOUT ( 7 ' ~le O N L ~ NO7 U S E D .*ullTH 7,4IB-?fiC)A

loPr\or\I

rS7

-

'

TO CH 2 READOUT '530A @

P/O A 2

IS

AMPLlFlER BOARDS

I 3