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SERVICE INFORMATION FROM HEWLETT-PACKARD
SEPTE MB E R-DECE MBE R 1976
1
I
1
LOGIC SYMBOLS RETRIGGERABLE MONO-
STABLE FLIP-FLOP
Using the above theory-of-operation
description of the device, we can show
how the notations used in Figure l a and
By Tom Trompeter forms for a Retriggerable Mono- I b provide the same information. For
I
stable Flip-Flop are shown in Figure 1. example:
I Editot's Note: Figure l a shows the device drawn in
I In the course of publishing these articles on
rectangular form using elements from the a. We said the ORed inputs are active low
logic symbology, BENCH BRIEFS has come standard. Figure I b shows the Same de- while the ANDed inputs are active
I
under some criticism along the line of, "why vice redrawn in an equivalent form, still high. Figure 2 graphically shows this.
another siand.wtl - what is wrong with the using elements from the standard. b. We said these inputs are ANDed to
MILSTD.8MF It smms many readers felt
these articles mere just another rehash o f lo@ produce "G". This i s illustrated by the
symbols. nothing really new -just different. As Contiguous Block diagram which
I Editor of BENCH BRIEFS I have been remifs
(1 shows the logic AND connection to
in not pointing out from the beginning that this produce "G". Refer to Figure 1b for a
standard, IEEE 91-1973,replmes MIL-STP806
and is approved for use by the Department of more graphic illustration.
I
Defense. Hewlett-Pwkard is in the procass of
adopting this standard as has another major
semiconductor manukturer.
I This series of articles has raised many questions
and that's good. Hopefully your iryopetite has
been whetted enough that you will obtain a
copy o f IEEE 91-1973 and take up where m e
have left off. Remember, we are living in a
world and working in an industry where u l t r a
rapid technological change is the rule. Logic
devices are more complex now than they used
t o be and the old traditional approach is simply
not edequate to deal with them. Complex
symbols stem from complex circuits, not the The Retriggarable Monostable Flip-Flop PRESETTABLE DECADE
Standard we follow. This means that you must is described twice here. The first time in
address your needs for training and be willing
COUNTE R/LATCH
theory-of-operationform, and the second
t o constantly reeducate yourselves and update The symbol for a Presettable Decade
the "tools** you use if you hope to keep up. time using the description of the device
Counter/Latch i s shown in Figure 3 The
.
HewIetMackard has gone to the IEEE Standard operaion to describe the logic notation.
so that the HP instruments manufactured
Decade Counter consists of a divide-
Extremely long output pulses can be by-two and a divide-by-five counter
throughout the world will have consistent
3 schematics from instrument-to-instrument. The generated because of the retrigger capa- formed by connecting pin 5 t o pin 6 and
ultimate benefactor will be the service bility. By trimring the inputs before the taking the output from pin 12.
technician who will have a much wsier repair output pulse i s terminated, the pulse
I job since schematic symbology and abbrevia- duration is extended. The pulse duration
I
tions are consistent from product-to-product.
i s terminated by making the "R" (reset) ISSUE
I want to thank Tom Trompeter for his series input (pin 5) low at a predetermined time
o f articles reflecting one of the first HP
divisions to produce schematics using the independent of the timing components.
standard. The ORed inputs are active-lowwhile the
ANDed inputs are active-high. These are
This i s the fourth and final in a series of ANDed to produce "G". When "G" goes
articles on the IEEE Standard 91-1973 high, the output pulses from pins 8
Graphic Symbols for Logic Diagrams (active high) and 6 (active low) start and
devices). This last article continue for the preset time period "t".
applies the qualifiers previously described This preset time period is determined by
t o monostable flip-flops, various either internal or external timing
counters, and LED display drivers. The circuitry, or until an "R" (Reset) input
following illustrations describe some occurs The reset input a t pin 5 can
applications of the rules and guidelines terminate the output pulses Whenever it i s
brought out in the previous articles. set active low.
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( I ) k S Y M B O L S
I
r ' I
The outputs may be preset to any state correspond to the data inputs indepen- LED DISPLAY DRIVER
by making "G" active low and entering dent of the state of the count-upldown
The symbol of a typical LED Display
the desired data a t the "Dc" inputs. The clocks a t pins 4 and 5.
Driver is shown in Figure 6. The LED
outputs a t pins 5, 9, 2, and 12 will then
Display Driver accepts a 4-bit binary code
correspond to the data inputs indepen- An active high signal a t pin 1 1 then
and provides output drive to light the
dent of the state of the count-up clocks enables the counter by latching the appropriate segments of a 7-segment
a t pins 6 and 8. An active high signal a t parallel data into the counter. When the
numeric display. The truth table in Figure
pin 1 then enables the counter by latch- counter is clocked a t pins 5 or 4, the 6 shows the possible alpha-numeric codes.
ing the parallel data into the counter. The outputs will change to the next appro-
count-up clock a t pin 8 clocks the + 2 priate state in the count sequence. The Latches on the four data inputs are
counter and pin 6 clocks the + 5 counter. "Dc" inputs are inhibited while "C" is controlled by the Enable (G2) input.
When the counter is clocked a t pins 8 or held high and have no effect on the When "G2" is active low, the states of the
6, the outputs will change on the counter. outputs are determined by the input data
negative-going edge of the signal. An code. When "G2" goes high, the last data
active low a t the "R" (reset) input (pin The terminal count-up (=15+1) or code present a t the input to the latches i s
13) causes all the outputs to go low terminal count-down (=O-I) outputs stored and the output remains stable.
independent of the counting state. (carry and borrow respectively) allow The LED Display Driver also has auto-
multidecade counter operation without matic blanking and zero suppression
SYNCHRONOUS 4-BIT UP/DOWN additional logic. As shown in Figure 5, through the ripple blanking input (RBI)
COUNTER the counters are cascaded by feeding the a t pin 5, and the ripple blanking output
terminal count-up output of the first (RBO) a t pin 4. The "GI" line always
The symbol for a Synchronous 4-Bit
counter to the second counter's count-up serves as an input; the "G3" line typically
Counter is shown in Figure 4. Operation
clock input, and the first terminal count- serves as an output but can also be
of the counter is synchronous, with the
down output to the second count-down configured as an input by connecting it to
outputs changing state after an active low
clock input. an external source. When "G3" is held
signal a t either the count-up clock
(+I) or count-down clock (-1) (i.e. the low by an external source, it overrides all
The counter is in state fifteen (generating
counter responds to a clock pulse on other inputs to the LED Display Driver
a carry) when the terminal count-up
either input by changing to the next and causes it to provide blanking outputs
output of the binary counter is active
appropriate state of the count sequence). to all segments of the associated display.
low. Similarly, when the terminal count-
The outputs actually change state on the down output is active low the counter i s When "G3" is not connected to an
. trailing edge of the input signal as shown in state zero (generating a borrow). Thus, external drive source it serves as a blank-
by the Output Delay Indicator ( 1).The when the binary counter is in state fifteen ing output which is controlled by "GI".
direction of counting i s determined by and counting up, or in state zero and As shown in the Truth Table in Figure 6,
which clock input i s pulsed with an active counting down, a clock pulse on pin 5 or the combination of an active low "GI"
low signal while the other clock input is 4 will change the counter's state on the and a binary 0 code causes the LED
disabled with an active high. Incorrect (or rising edge and simultaneously clock the Display Driver to set the RBO output low
undefined) counting will occur if both second counter through the appropriate and to provide blanking outputs to all
clock inputs are active low terminal count output. There are two segments of the associated display. For
simultaneously. gate delays per state when these counters zero suppression, the RBI line associated
The counter has the ability to parallel are cascaded. When the asynchronous with the most significant digit is
load (asynchronous) input data (preset master reset "R" input goes active high, it grounded and the RBO output is con-
the counter). This i s accomplished by overrides all other inputs and clears the nected to the "GI" input of the next
making "C" active low and entering the counter. An active high signal a t the "R" significant digit. Using this configuration
desired data a t the "DC" inputs. The input causes all the outputs to go low a number such as 0010 would be dis-
outputs a t pins 3, 2, 6 and 7 will then independent of the counting state. played as IO. 0
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LOGIC SYMBOLS 1 1::
1 i
TRUTH TABLE 1976 APPLICATION NOTE
~
INDEX
BINARY -- Jpu , OUTPUTS
DATA - G2 -
cc ITR( DATA )ISPLAY
INPUT
- - 63
61
- 8 4 2 1 a b c d e f gRBO Hewlett-Packard Application Notes are a
- ** compilation of applications research and
H x x x x STABLE H ;TABLE
experience which have been written in
** collaboration with HP engineers and our
0 L L L L L L H H H H H H H L %LANK
customers.
0 H L ** L L L L L L L L L L H H 0 Some notes are tutorial in nature, while
** others describe very specific "how to"
1 X L L L L H H L L H H H H H 1
procedures. Copies are available from
** your local field engineer or sales office
2 X L L L H L L L H L L H L H 2
(refer to the updated l i s t in this issue of
** Bench Briefs).
3 X L L L H H L L L L H H L H 3
4 L ** L H L L H L L H H L L H 4 The Application Note Index abstracts the
X
current notes available. A listing of the
5 X L ** L H L H L H L L H L L H 5 HP instruments for which notes have
been written is included as well as a
6 X L ** L H H L L H L L L L L H 6 subject index.
7 L ** L L L H H H H H 7
X L H H H If you wish to receive a copy, w r i t e on
your letterhead to
a **
X L H I L L L L L L L L L H 8
9 X L
**
H L L H L L L H H L L H 9 I.M. Smith, Editor
Hewlett-PackardCompany
10 X L
** H H H H H H L H Corporate Marketing Communications,
H L H L - (dash)
19L
** 1501 Page Mill Road
11 X L H L H H L H H L L L L H E
Palo Alto, CA 94303
12 X L
** H H L L H L L H L L L H H
**
13 X L H H L H H H H L L L H H L
14 ** L L H H L L L H P
X L H H H L
** H H H H H H H H
15 X L H H H H 3LANK
X X X L x x x x H H H H H H H ** 3LANK
- --
H = HIGH; L = LOW; X = DON'T CARE CONDITION
*The GI input will blank the display only if a binary zero is stored in the latches.
* * The RBO output (pin 4) when used as an input (G3)overrides all other input
conditions.
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llll
ATTENTION 3490A II Interpreting Flowcharts
Ill Additional Logic Circuits
MULTIMETER USERS
IV Identification of Logic Problems
V Troubleshooting
A new service note, 3490A-14, has been
issued that provides detailed information V I 3490A ASM Flowcharts
on digital troubleshooting in the 3490A owners 3 9 0 ~
of ~ ~ order
can l ~ i ~ ~
Multimeter. The topics covered are: the service note with the order form
I Understanding Algorithmic State located on the inside last page of Bench
Machine (ASM) in the 3490A Briefs.
". . . call your local HP find themselves outgrowing their facilities
and moving to larger quarters. Occasion-
To make sure that you can easily locate
your local HP office to obtain the service
office. . . 99
ally an additional office i s added to serve you have come to expect of Hewlett-
an area. These changes may mean that an Packard, here's an up-to-date listing of
HP office is now more conveniently field offices for all areas of the world.
That's a phrase frequently Seen in HP
located for you. A bullet ( 0 ) by the office serving your
publications. It appears with shipping
instructions, parts ordering information area indicates that there has been a
and service literature. That phrase Although many HP manuals and other change in address or telephone number,
reminds you to call your local HP office publications contain a complete l i s t of HP etc. during the past year. It may be
if you need help. But to do that you must offices, the list may not be completely helpful to note the new information and
know where to find your local HP office. current since it is revised only when the to pass it along to others in your facility
As HP continues to grow, many offices publication is reprinted. also.
AFRICA, ASIA, AUSTRALIA
POT.'
wG- tndrmril P.T.
I
dS
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SALES AND SERVICE uttictS
EUROPE, NORTH AFRICA AND MIDDLE EAST
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IRAN
Mwlmplcxsrd Iran Lld
WE s Amw
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T l x M717W179 W + a c k u d Esprnola S A
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Td (I) 4 4 2d 00 (10 trms)
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CENTRAL AND SOUTH AMERICA
HIVMI-RClrrrd do MI MEXICO
I.E.C. LMS. Harl*F,ackHd Mexkml,
S.A. de C.V.
T o m Ada!4d No. 21. 11' Rso
Cd. d d Wb
Td: 2516094-DOo (021J. Y a k o 12. O.F.
T l x : 38-212-605 HEW BR Td: (905 543-42-32
WUWI W:HEWPACK Tdsx: 01\-74-507
SMlbVlr 6 uvll ( W h ) LMS. Rlo de Jlnim
Hwi?all-Brd Mexicsns,
Av. yabul. Smb Cnu 1342 COSTA R(w S.A. da C.V.
L.Pn WntrAca Cortamwnrs S A Ave. cOnsll!ubbn NO.2184
Td: 40626.53163. 52421 Calla W l Avaidas Iy 3
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Tlla: 3560014 AQmdo 10159 T?%??hNk71-84
clwr BUKYAR nmw Telex: 036Mh
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Cabk GALGUR San Jwd
ECUADOR
M a u l only
A.F. VLICrho Cornpanla Llda
Av. RIO A m a m No. 239
P.O. Box 2925
Oul(0
Taf: 242-150 2474!WON ,COWTACT:
WE: lstor buito
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Ii :1 11 SAFETY-RELATED SERVICE TIPS
-
UNITED STATES
MAMU4 WNo18 YICWQAN NEW V O M
rn Whilesburg Of , S E ssoo HOWVd streal
Skokh 60078
23855 Msoarch Onve 6 hilonullon Lane
P O Box4207
Hwt.rY. 35802
2220 Wm A w
SewmunW 95825 l d 1312 677-
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W 91b-223-3613
Td: z
& (5789458-1550
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T (205) 1 4 5 9 1
d 1 Id (9161 482.1463 TWX: 7lb441-8270
OBW Aao Drke YulWEeoTI PLNNWLVAWA
P O BOX23333 2400 N Pnor Ave 111 2 Onw
-
8.n M.po 92123 Rourllh 55113 pmbuoh 15238
T (714) 2793200
d T (612 638-0700
d l d (412 7824400
TWX 9lb-S-3734 TWX 7lb-795-3124
coLO(uD0
S I south Wsla Parkway
K WASIUIOTON
EngbwoOd Sol10 `J#*.on Bd!&d6M(il!ePk
Td (303) 7715455 MMcal SaMI,on 12W114th A S E
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Twx 71b-4652029 co)unb* 29260
T (803) 7824493
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FLOROI
P 0 Bow 24210
28w W Q W Park Blvd IUWTWXV TENSESSEE
n.Lm#U&# 33307 Medl1 O W `Kmdh meco#un
Td (W) 731-2020 Atlenpon Spurs N m CAROLINA
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usdlul S m only 9004 W a l L w l n Avl.
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Wle 207
P O Box5159
1923 NaMl Man Streal .&&
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T I6151 523-5022 Wu( AIIb 53227
la(: (414) 541-0550
Lsu*ruh40218 MMul SWPXon1
T (502) 458-1573
d Vl9T%78:50: Tal: (615) 244.544l
P 0 Box 13910
6177 WO EYnM Dr LOUISIANA OH0 TEXAS
oflwlda 3 2 0 PO B w m lssW spraoue Roa4 P 0 Box 1270
Td (305)8592800 3239 william Boulevard am*nd U 1 M 201 E A q a h o Rd
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P O Boa 128%
Pmuwk 32575 Tat (504) 721-6201 TWX 81b23-9431 ?f%ZlLV
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434-2081 3 3 Rcqras Rd
0- 45449
QEmmA 14 (513 8568202
8 FOR U S MUS NOT USTED
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P O Bmlosw5 NEW yulco TWX 8lb-474.2818 contacl ma rspiona~
onica
AUn& 30348 P.O. Box 11634 1041 KingsmiU Parkwaq warst you Atlanta. Glwoia
Td (4M) 955-1500 station E co(Unbw 43229 205 Billq Milchdl Road
NDRh Hal ood California
TWX 810768-48% 11300 Lomas Blvd., N.E R ~ W I UC.y m Rolling Meadows.
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Td. (614) 436-1041 Sm Antonla 78226 Illinois TMr complae
!4emcal swncs OW Tel (512) 434-8241 addre.sse-3 are listed abow
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156 anoms Okwlonu CUy 73132
L %a 88w1
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l W X 916-9834550
7176
SAFETY-RELATED 740NB AND 3420NB TEST PROCEDURES
VOLTMETERS Turn the power switch OFF, discon-
SERVICE NOTES nect all power cords and grounding
These instruments have a POTENTIAL straps from the instrument.
Service Notes from HP relating to per-
sonal safety and possible equipment SHOCK HAZARD. If the instrument i s - Set the ohmmeter to the 1K ohm
damage are of vital importance. To make floated above ground, control shafts (and range.
you more aware of these important notes, control knob set screws) are above
ground potential. In order to test your 740AlB
HP has recently modified the Safety
Service Note format. The note is now instrument for this potential shock -Connect the Input Cable Assembly
printed on paper with a red border, and a hazard refer to the abbreviated test proce- (1 1054A) to the 740AlB.
" - S" suffix has been added to the dure below. Please note that more - Check for continuity between the -
note's number. In order to make you detailed instructions are available on the (minus) terminal on the cable assem-
immediately aware of any potential applicable Service Notes. bly and all of the set screws of each
safety problems, we are high-lighting control knob.
safety-related Service Notes here with a If the instrument fails the test it can be
brief description of each problem. Also, Infinity = OK
made to conform to current safety
in order to draw your attention to 3420AlB
standards with one of the appropriate
safety-related Service Notes on the Ser-
vice Note order form at the rear of
modification kits. - Check for continuity between the
INPUT LOW terminal and all of the
BENCH BRIEFS, each appropriate
740AlB - Kit No. 00740-87901 set screws of each control knob.
number i s highlighted by being printed in
color. 3420AlB - Kit No. 03420-89501 Infinity = OK
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.
CUSTOMER SERVICE SEMINARS t
I
Hewlett-Packardcontinually offers training to customers on UNITED STATES TRAINING
a world-wide basis to help keep service skills current with
HP`s extensive product line. Seminars are provided through- Several service seminars are being offered by Hewlett-
out Europe and the United States in an effort to bring our Packard next year in several locations around the U.S. The
training facilities closer to your area. lectures are given in a lab-type environment so students will
have ample opportunity for hands-on experience.
EUROPEAN TRAINING
For registration please use the form on the last page of
Service seminars in Europe are offered on a supply-and- Bench Briefs or contact your Hewlett-Packard Sales and
demand basis. For HP to have a better idea of customer Service Office.
needs, please fill out the questionnaire form on page 14 of
Bench Briefs and mail it to the Geneva address.
'
I
5345A ELECTRONIC COUNTER 534OA MICROWAVE FREQ COUNTER
FEB 7-9, PARAMUS, N.J. MAR 7-8, SANTA CLARA, CALIF.
COURSE CONTENT COURSE CONTENT
LECTURE LECTURE
I. General Features I. Overall Block Diagram
11. Overall Block Diagram Description 11. Numerical Examples of Frequency Measurements
111. Circuit Descriptions 111. Input Phase Lock Loop Circuit Description
A. Input Circuits IV. Transfer Phase Lock Loop Circuit Description
B. Control Circuits V. Instrument Flow Diagram and Algorithmic State
C. Scaler Circuits Machine
D. Processor Circuits VI. Options
IV. Explanation of Algorithmic State Machine
Flowcharts
LAB
LAB The lecture is given in a lab environment. Attendees make
I. Explanation of Troubleshooting Flowcharts using voltage and waveshape measurements at different times
the HP 1600A Logic State Analyzer and the 5345A during the lecture. A familiarization with adjustment
ASM Tester. procedures is also included.
m PREREQUISITES - Familiarity with digital logic and
PRESTUDY
integrated circuits.
- "The Fundamentals of Electronic
Frequency Counters", Application
PREREQUISITES - Basic knowledge of microwave
PRESTUDY
measuring techniques
- April 1973 HP Journal describing
5340A. "The Fundamentals of
Note 172. 5345A Users Handbook, Electronic Frequency Counters",
HP Part Number 5952-0886D. Application Note 172.
8660 SYNTHESIZED SIG GEN LECTURE
MAR 14-15, LOS ANGELES, CALIF. 1. Introduction to 8660 System
A. System Block
MAR 28-29, RICHARDSON, TEXAS
B. Specifications
MAR 30-31, PARAMUS, NJ C. General Operation
1. Mainframe
2. RFSection
3. Modulation Section
D. Indirect Generation (Video Tape)
11. 8660 Theory
A. Reference and Loops
B. DCU
C. Remote Programming
Ill. 86601A
A. Operation and Controls
B. Mainframe Interface
C. Functional Block Theory
D. Adjustments
E. Module Level Troubleshooting
F. Lab
1V. 86632 thru 86635
A. Operation and Controls
B. Mainframe Interface
C. Functional Block Theory
D. Adjustments
COURSE CONTENT E. Module Level Troubleshooting
F. Lab
V. 86602B/ 11661B/86603A
This course includes the following components of the A. Operation and Controls
8660 System: B. Mainframe Interface
C. Functional Block Theory
D. Adjustments
8660A Thumbwheel Mainframe
E. Module Level Troubleshooting
8660C Keyboard Mainframe
F. Lab
86601A RF Section 0-1.10 MHz
866028 RF Section 1-1300 MHz LAB
86603A RF Section 1-2600 MHz The lecture is given in a lab environment
866328 Modulation Section
PREREQUISITES - Good understanding of Digital Logic
86633A Modulation Section
and Basic Phase-Lock circuits
86634A Modulation Section
86635A Modulation Section PRESTUDY - 866OC Manual; View Video Tapes
116618 Frequency Extension Module 90030--566 (Optional)
HAPPY 45ElLIBAY3
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SERVICE TIPS
a 8640 AM/FM SIGNAL GENERATOR
MAR 16-17, LOS ANGELES, CA
LECTURE
COURSE CONTENT
MAR 28-29, PARAMUS, NJ
1. Introduction
MAR 3@31,RICHARDSON, TEXAS
II. Features and Model Options
Ill. Front Panel Features
A. VideoTape
B. Demonstration
IV. Theory
A. Block Diagram
B. Assembly Locations
C. Schematic
LAB
I. Adjustments
11. Performance Tests
111. Troubleshooting
PREREQUlSITES - Basic knowledge of digital logic
circuits and general knowledge of
electronics including operational
amplifiers
PRESTUDY - Review digital logic and block diagram
information in 8640B manual.
Read pages 1-48 in "Signal Generator
Seminar" text book.
435A POWER METER RANGE DIAL CONVERSIONS
P
Depending on which power sensor you
attach to your 435A, you can measure
power from 0.3nW (- 65 dBm) to 3W
(+35 dBm) full scale. Each power sensor
has its own calibrated range dial located
on the RANGE knob that corresponds to
the measurement capabilities of the
sensor. `In order to change ranges you
must remove the RANGE knob and select
one of the correct calibrated dials. One
range dial has scales printed on both sides
while the other dial has only one scale.
The following table shows which range
dial goes with which power sensor.
Service Note 435A-2 provides complete on
details on changing the knob assembly
(HP P/N 00435-60030) on 435A's with
serials 1527A and below.
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SERVICE TIPS
II
CLEANING AND 3. Lubricant (Low Impedance and is as effective as the Elecfrolube 2G
Switches) for lubrication of tow impedance
LUBRICATING 6 02. aerosol spray can switches.
ROTARY SWITCHES Electralube 2A
Electrical Contact Lubricant
HP Part No. 6040-0300
Electrolube 2A is also available High Impedance Switch Lubrication
Electrolube Corporation
Syosset, New York 11791
4. Artist's brush
piikijq
In the next four steps, do not
A No. "1" or "0" artist's brush permit the lubricant to come in
HP Part No. 8520-0004 contact with any components
The following procsdures can be used for (Also available from office or art mounted on the switch; otherwise
rotary and pushbutton switch mainte- supply stores.) leakage paths may result and the
nance to extend the life of the switch and lubricant may act as a solvent on
assure extended reliable performance. so m e materials (Lexan,
Contamination on a switch in viscous or Polystyrene).
similiquid form can hold dirt and dust CLEANING PROCEDURE:
particles which, in turn, can cause leakage
paths, abrasion of the switch contacts, 1. With the artist's brush, apply a small
etc. The lubricants used on switches can amount of Electrolube 2G sparingly to
evaporate and deteriorate with time and the wiper blade in one circular motion.
During this procedure, keep the
exposure to the elements. As this (The amount referred to i s the
switch free from contamination t o
happens, wear and galling are produced, thinnest possible coat you can apply
preserve accuracy and performance.
particularly in high usage switches. The with the brush.)
materials recommended for use in this
article remove the contamination and
provide a long-life, oxidation-resistant
lubrication which will extend the life of
If the switch is used in a high
impedance circuit, clean rubber
gloves should be worn at all times. 2. With the artist's brush, apply a small
amount of lubricant sparingly to the
a
1. Place a paper towel or other suitable inside of each contact if possible.
Kel-F (translucent plastic material), material under the switch to catch any
phenolic, and ceramic wafer switches are residual cleaning spray.
3. Repeat the procedure (Steps 1 and 2)
acceptable for this cleaning and lubrica- on each side of wafer.
Some components may be damaged 4. If the wafers are relatively inaccessible,
with cleaning spray. Avoid pro- a small drop deposited on the wiper
longed direct contact with compo- blade should provide reasonable dis-
MATERIALS R EQUI RED : nents and susceptible plastics. tribution of the lubricant after sev-
eral rotations of the switch.
1. Cleaner spray 2. Thoroughly spray the contact wiper
16 02. aerosol spray can blades with the recommended spray.
Freon TF Cleaner
HP Part No. 8500-0232 3. Rotate the switch from stop to stop
Freon TF is also available from: and allow to dry completely.
Excessive amounts of the lubricant
M iller-Stephenson Chemical
are not necessary for proper lubri-
Co., Inc.
cation. Excessive amount of lubri-
Danbury, Connecticut 06810
LUBR CATION PROCEDURE: cant increases the dust and particle
2. Lubricant (High Impedance adhesion.
The Electrolube 2G paste lubricant
1/40.7. bottle (paste) should be used rather than the Electro-
Electrolube 2G lube 2A aerosol lubricant for high NOTE
Electrical Contact Lubricant impedance switches due to the contamin-
HP Part No. 5060-6086 ation of the switch by the aerosol lubri- Electrolube 2G contains an antioxidizing
Electrolube 2G is also available in cant. Low impedance switches do not a p n t which turns a reddish-brown color
1/2 Ib. cans from: have serious contamination problems thus when exposed to the air for several hours.
Electrolube Gorporation the aerosol lubricant can be used. The This discoloration in no way affects the
aerosol lubricant is much easier to apply lubrication and conductive qualities.
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