Tektronix 305 DMM User manual

Tfektronix
305 DMM
OSCILLOSCOPE
OPERATORS
INSTRUCTION MANUAL

Tektronix. Inc.
P.0. Box 500
Beaverton. Ore on 97077
070-2424-00

Tektronix
COMMITTED TO EXCELLENCE
PLEASE CHECK FOR CHAN E
INFORMATION AT THE REAR
OF THIS MANUAL
305 DMM
OSCILLOSCOPE
OPERATORS
INSTRUCTION MANUAL
First Printin JUL 1978
Serial Number ----------------------------- Revised JUL 1981

Copyri ht e 1978 Tektronix, Inc. All ri hts
reserved. Contents of this publication may not be
reproduced in any form without the written
permission of Tektronix, Inc.
Products of Tektronix, Inc. and its subsidiaries
are covered by U.S. and forei n patents and/or
pendin patents.
TEKTRONIX, TEK. SCOPE-MOBILE, andf^?*
are re istered trademarks of Tektronix, Inc.
TELEQUIPMENT is a re istered trademark of
Tektronix U.K Limited.
Printed in U.S A. Specification and price chan e
privile es are reserved.

TABLE OF CONTENTS
Pa e Pa e
LIST OF ILLUSTRATIONS ii
LIST OF TABLES iii
GENERAL INFORMATION 1ADJUSTMENT AND BASIC DISPLAY 17
Introduction 1Oscilloscope Display 17
Safety Information 1Di ital Multimeter Display 20
Operatin Volta e 2APPLICATION AND MEASUREMENTS 22
Internal Battery Operation 4
Battery Char in 5Instantaneous Amplitude Measurements-DC 22
Battery Care 5Peak-to-Peak Amplitude Measurement-AC 24
Volta e Comparison Measurements 25
CONTROLS AND CONNECTORS 6Time Duration And Frequency Measurement 20
Power Source And Connectors 6Time Difference Measurement Between Two
Calibrator And Display Controls 8 Pulse Waveforms From Different Sources 27
Vertical Controls 8 Dual Trace Phase Difference Measurements 28
Horizontal Controls 11 Hi h Resolution Phase Difference Measurement 30
Tri erin And Sweep Controls 12 Rise Time Measurement 31
Di ital Multimeter Controls 14 Common Mode Rejection 32
BASIC INSTRUMENT OPERATION 15 SPECIFICATION 33
Operatin Considerations 15 Electrical Characteristics 33
REV A SEP 1979 305 Operators

LIST OF ILLUSTRATIONS
Pa e Pa e
Fi ure 1. Description of power source operation. 3Fi ure 13. Example of peaktopeak volta e
Fi ure 2. View of rear cover. 6measurement. 24
Fi ure 3. Ri ht side view of instrument cabinet. 7 Fi ure 14. Example of time duration and frequency
Fi ure 4. Left side view of instrument cabinet. 7 measurement 26
Fi ure 5. Location of display and calibrator controls. 9Fi ure 15. Time difference between two pulses from
Fi ure 6. Location of vertical deflection system different sources. 27
controls. 10 Fi ure 16. Example of dual trace phase difference
Fi ure 7. Location of horizontal deflection system measurement. 28
controls. 11 Fi ure 17. Example of hi h resolution phase difference
Fi ure 8. Location of tri er and sweep controls. 12 measurement. 30
Fi ure 9. Location of di ital multimeter controls. 14 Fi ure 18. Example of rise time measurement. 31
Fi ure 10. Probe compensation. 16 Fi ure 19. Common mode rejection of an undesired
Fi ure 11. Location of external operator adjustments. 19 line frequency. 32
Fi ure 12. Example of instantaneous volta e measure
ment with VOLTS/DIV set at 10M
position. 23
ii 305 Operators REV A SEP 1979

LIST OF TABLES
Pa e
TABLE 1. Battery char e related to operatin tem
perature and char in temperature. 5
TABLE 2. Electrical Characteristics 33
@305 Operators iii

305 DMM Oscilloscope
@
305 Operators

ENERAL INFORMATION
INTRODUCTION
The Sony/Tektronix 305 DMM Oscilloscope is a versatile
solid-state (except crt> portable instrument that combines
small size and li ht wei ht with the ability to make preci
sion waveform and di ital measurements associated with
industrial, military, computer maintenance, and business
machine applications. The 305 is mechanically constructed
to withstand shock, vibration and other environmental
extremes associated with portability. Operatin power for
the instrument is provided by external dc, rechar eable
batteries, or normal power-line volta e. Internal circuitry
rechar es the batteries whenever the instrument is connect
ed to power-line volta e. Selection of the DMM or oscil
loscope function (or both} is made with front panel push
buttons.
The DMM is autoran in and measures resistance, ac
volta e and dc volta e. Full scale measurements are 2 me 
ohms, 700 Vac and 1000 Vdc. The front panel di ital read
out is a 3-Vi di it display containin an automatic ne ative
polarity indicator and decimal point locator. No polarity
indication is shown for positive measurements. Input con
nectors for the multimeter are located on the ri ht side of
the instrument cabinet.
Oscilloscope functions provide dual-channel, dc to 5
me ahertz vertical deflection with calibrated deflection
factors of 5 millivolts/division to 10 volts/division in a 1-2-
5 sequence. The horizontal deflection system provides cali
brated sweep rates from 0.5 second to 1 microsecond per
division. A X10 ma nifier increases the indicated sweep rate
by a factor of ten, extendin the fastest sweep rate of 0.1
microsecond/division. The tri er input may be internal or
external, with tri erin effective over the full bandwidth
of the vertical deflection system. Calibrated X-Y measure
ments are made with Channel 2 (Y) providin the vertical
deflection and Channel 1 (X) horizontal deflection. Oscil
loscope si nal input connectors are located on the left side
of the instrument cabinet The crt display is an 8 X 10 di
vision raticule with each division measurin 0.632 centi
meters (approximately 0.25 inches).
SAFETY INFORMATION
This operatin manual contains information which the
user must follow to ensure safe operation of the instru
ment. Warnin information is intended to protect the
operator while Caution information protects the
instrument.
REV A SEP 1979 305 Operators 1

WARNING
High voltage is present inside this instrument. To
avoid ele tri -sho k hazard, operating personnel
must not remove the prote tive instrument
over. Component repla ement and internal ad
justments must be made by qualified personnel
only.
In the ac power source mode, the 305 DMM Oscillo
scope operates from a sin le phase power source, which
has one of its current carryin conductors at round (earth)
potential. Operation from other power sources where both
current carryin conductors are live with respect to round
(such as phase-to-phase on a multi-phase three wire system I
is not recommended because only the line conductor has
over-current (fuse) protection within the instrument.
This instrument has a 3-wire power cord with a 3-
contact plu for connection to the power source and to
protective round. The plu protective- round contact con
nects (throu h the cord protective roundin conductor) to
the accessible metal parts of the instrument. For electric-
shock protection, insert this plu into a socket outlet that
has a securely rounded protective- round contact.
L)o not defeat the roundin connection. Any interrup
tion of the roundin connection can create an electric-
shock hazard. Before makin external connections to this
instrument, always round the instrument first by connect
in the power cord to a proper matin power outlet, that
is known to be properly rounded.
OPERATING VOLTAGE
This instrument may operate from an external dc source,
rechar eable batteries (supplied with the instrument), or a
115 or 230 volt ac nominal line volta e.
External DC Power Source Operation
The 305 can operate from an external dc power source
of +9 to +32 volts. Set the Power Source Selector switch to
the EXT DC position (Fi ure 1). Apply external dc volta e
to the two banana jack inputs usin the cable assembly
supplied with the instrument.
Internal Battery Power Source Operation
To operate the instrument from the internal battery
source, set the Power Source Selector switch to the BAT
TERY position (Fi ure 1). Battery volta e is indicated on
the DMM di ital readout when all DMM FUNCTION push
buttons are in the out position.
2305 Operators REV A SEP 1979

E A i cknhl ia . rvmen suunv-c urcnmiun
L
L
L
L
t
L
L
iL
AC L IN t V U LI A lib H A N lit IN U ICAI UK
a ) INDICATES NOMINAL AC INPUT VOLTAGE (116 OR
> < 230 V) FROM WHICH INSTRUMENT MAY BE
B ) OPERATED.
©
POWER SOURCE SELECT SWITCH
OPERATES 305 FROM AC OR EXT DC POWER
SOURCE WITH FULL CHG APPLIED TO INTERNAL
BATTERIES.
©OPERATES FROM AC OR EXT DC POWER SOURCE
WITH TRICKLE CHG APPLIED TO BATTERIES.
©OPERATES 305 FROM INTERNAL BATTERY POWER
SOURCE
AC POWER SOURCE OPERATION
©CHECK THAT THE AC LINE VOLTAGE RANGE
INDICATOR DISPLAYS THE NOMINAL AC LINE
VOLTAGE AVAILABLE I115 OR 230 V AC).
®SET THE POWER SOURCE SELECT SWITCH TO AC,
FULL OR TRICKLE CHG.
WARNING I
©WHEN OPERATING FROM EXTERNAL DC OR
INTERNAL BATTERIES THE INSTRUMENT GROUND
CONNECTOR MUST BE CONNECTED TO A
PROTECTIVE EARTH GROUND.
©
©
SET THE POWER SOURCE SELECT SWITCH TO ONE
OF THE EXT DC POSITIONS.
APPLY EXTERNAL DC POWER SOURCE h9 TO
♦ 32 V DC) TO THE BANANA JACK INPUT.
©
BATTERY POWER SOURCE OPERATION
SET THE POWER SOURCE SELECT SWITCH TO
BATTERY POSITION. _________
IWUtiMM
’ C ti U T M i U i
ocron<i«oti*cc
(2423 0712424 26
Fi ure 1. Description o f power source operation.
REV A SEP 1979 305 Operators 3

WARNING I
Change of a voltage must be a omplished by
qualified servi e personnel.
AC Power Source Operation
The AC Input Volta e Selector switch permits the 305
to be operated from a 115 or 230 volt ac nominal line volt
a e source, at 48 to 440 hertz I Fi ure 1) The Power Source
Selector switch must be set to the proper AC position. The
ac line volta e fuse must be chan ed when selectin a dif
ferent nominal line volta e. Any fuse chan e requires re
moval of the instrument cabinet and must be accomplished
by qualified service personnel.
INTERNAL BATTERY OPERATION
WARNING I
Change or repla ement of batteries must be a om
plished by qualified servi e personnel
I ne jud teatures oattery operation irom six recuarye-
able nickel-cadmium cells (1.2 volts each, total nominal
volta e of 7.2 Vdc). The operatin time of the internal
batteries depends upon display intensity, state of battery
char e, dischar e temperatures, and the instrument function
bein used; oscilloscope, DMM, or both. When the instru
ment is operated at +20°C to +303C (+C8 F to +86°F),
the typical operatin time of fully char ed batteries with
both oscilloscope and DMM in operation is approximately
1.6 hours.
A li ht-emittin diode (LED), labeled 'ON (FLASHES
WHEN LOW)', is steadily illuminated to indicate that the
instrument oscilloscope function is on, and the battery
char e is sufficient for operation. When battery char e is
low, the LED flashes on and off indicatin that batteries
require rechar e or possible replacement. An automatic
battery over-dischar e protection circuit will turn the instru
ment off to prevent excessive dischar e, which could result
in permanent battery dama e.
Durin DMM operation, the di ital readout alternates
between a normal display and---------------if the power
source volta e drops too low for proper DMM operation.
4305 Operators REV A SEP 1979

BATTERY CHARGING TABLE 1
To apply full char e to the batteries, connect the instru
ment to a power line, turn SCOPE POWER and DMM
POWER off, switch the Power Source Selector switch to
AC FULL CHG position, and allow at least 16 hours for the
batteries to become fully char ed. To obtain the lon est
Operatin life for the batteries, the instrument should be
turned on at least once a month and the batteries dis
char ed to where the oscilloscope SCOPE POWER LED
flashes, and then rechar ed for 24 hours. This procedure
balances the char e on the batteries and reduces the
possibility of any cell becomin reverse char ed The
instrument may be operated while batteries are bein
char ed.
The ener y capacity of nickel-cadmium cells varies with
the temperature at which they are char ed and operated.
Table 1 shows the percenta e of full char e capacity at
various char in and operatin temperatures.
Battery char e related to
operatin temperature and char in temperature.
Char in Operatin Temperature
Temperature -15° C +20° to +25" C ♦55s C
0°C 40% 60% 50%
♦20° to +25° C 65% 100% 85%
*40° C 40% 65% 55%
BATTERY CARE
Nickel cadmium cells will self-dischar e when the instru
ment is not used often or stored for extended periods of
time. The rate of self-dischar e is dependent upon tempera
ture and humidity. When the instrument is to bo stored for
extended periods of time, particularly at hi h temperature
or humidity, the batteries should be char ed for at least
16 hours every two weeks, or leave the 305 connected to a
power line with the Power Selector switch set to AC
TRICKLE CHG position.
<® 305 Operators 5

CONTROLS AND CONNECTORS
Controls and connectors necessary for proper operation
of the instrument are located on the front, side, and rear
cabinet panels. To make full use of the capabilities of this
instrument, the operator should be familiar with the func
tion and use of each external control and connector. A
brief description and use of each external control and con
nector is iven herein
POWER SOURCE AND CONNECTORS
WARNING |
Change o f a input voltage must be a om
plished by qualified servi e personnel only.
1. Power Source Selector switch-Three position switch
provides operator selection of ac line volta e, external dc
volta e or battery operation. The ac position, in conjunc
tion with the AC Input Volta e Selector switch, allows the
305 to be operated over a ran e of ac line volta es. Power
Source Selector switch also provides operator selection of
a Full or Trickle char e rate to internal batteries (Fi ure 21.
2. AC Input Volta e Selector switch-In conjuction
with the Power Source Selector switch, allows the instru
ment to be operated from 115 or 230 nominal ac line
volta e (Fi ure 2).
Fi ure 2. View of rear cover.
6305 Operators REV A SEP 1979

3. + and - Inputs for applyin external dc power
source {+9 to +32 volts! {Fi ure 3).
4. DMM INPUT-Connector to apply external volta es
or resistance to be measured to the di ital multimeter
(Fi ure 3).
5. Ground Connector-Connector for common round
connection from the power source or associated instruments
or devices under test {Fi ure 3).
6. CHI (X) INPUT-BNC connector to apply an external
si nal to the input of the CHI vertical system, or X-axis
deflection {horizontal) in the X-Y mode of operation
(Fi ure 4). The maximum safe ac or dc volta e coupled to
the CHI (CH2 or EXT TRIG INPUT, if applicable) input
connector should not exceed 250 V (dc + peak ac).
7. CH2 (Y) INPUT-BNCconnector to apply an external
si nal to the CH2 vertical system, or Y-axis (vertical) in the
X-Y operation mode (Fi ure 4).
8. EXT TRIG INPUT-BNC connector to apply an ex
ternal tri er input si nal (Fi ure 4).
9. Ac Line Cord-Connects the instrument to an ac
power source (Fi ure 3). The cord may be conveniently
stored by wrappin it around the feet on the rear cover
(Fi ure 4),
Fi ure 3. Ri ht tide view of instrument cabinet. Fi ure 4. Left side view of instrument cabinet.
REV A SEP 1979 305 Operators 7

CALIBRATOR AND DISPLAY CONTROLS
(FIGURE 5) VERTICAL CONTROLS (FIGURE 6)
10. SCOPE POWER-Pushbutton switch turns the oscil
loscope on (ini and off (out).
11. INTENSITY-Controls the bri htness of the crt
display. Turn the control clockwise to increase display
bri htness.
The intensity level should be set to the lowest visible
display to prolon life of the crt.
12. ON (FLASHES WHEN LOWI-LED indicator that
lows reen when SCOPE POWER is on and power is
applied to the oscilloscope
The LED flashes on and off when batteries require re
char in and then oes out when the batteries are complete
ly dischar ed.
13. .3V CAL OUT (Calibrator)-Pin connector output
provides an internally enerated 0.3 volt, 1 kHz square
wave. Calibrated volta e is useful for checkin vertical de
flection factor and probe compensation.
14. POSITION (CHI or X and CH2 or Y)-Controls the
vertical position of the crt display for each channel. In the
X-Y mode of operation, the CHI (X) controls the position
of the display horizontally and CH2 (YJ controls the posi
tion of the display in the vertical direction.
15. VOLTS/DIV (CHI and CH2)-Selects vertical de
flection factor of si nals applied to the CHI and/or CH2
INPUT connectors. The CAL (Variable! control must be in
the CALibrated detent for the indicated deflection factor.
16. VOLTS/DIV CAL (Variable) (CHI and CH2)-Control
(concentric with the VOLTS/DIV switch) provides contin
uously variable uncalibrated deflection factors between the
calibrated settin s of the VOLTS/DIV switch. Extends the
maximum deflection factor to at least 25 volts per division.
17. 5 DIV CAL-Position on the VOLTS/DIV switch
that internally connects a calibrated si nal to the vertical
preamplifier circuit. Useful for checkin instrument vertical
deflection ain.
18. PULL INVERT-Pull the Variable knob to the out
position to invert the CH2 si nal display.
8305 Operators REV A SEP 1979

305 Operators 9

Fi ure 6. Location of vertical deflection system controls.
selects method of couplin the input si nal to the vertical
deflection system.
AC: Input si nal is capacitively coupled to the vertical
attenuator circuit. Dc component of the input si nal is
blocked. Lower frequency lim it (lower —3 dB point) is
about 10 hertz.
GND: Connects the input attenuator to round provid
in a zero ( round) reference volta e display (does not
round the input si nal). Allows prechar in of the vertical
input couplin capacitor by applyin the input si nal via a
one me ohm resistor.
DC: All components of the input si nal are directly
coupled to the vertical attenuators.
20. Display Mode-Five position lever switch that selects
the operation mode of the vertical deflection system (si nal
displayed on the crt).
CHI: Displays the si nal applied to the CHI (X) INPUT
connector.
CH2: Selects the si nal applied to the CH2 (Y) INPUT
connector for display. The CH2 mode position is selected
for X-Y operation (in conjunction with X-Y position of SEC/
DIV switch) and provides vertical deflection from the CH2
INPUT.
10 305 Operators REV A SEP 1979

tween the si nals applied to the CHI and CH2 INPUT con
nectors. This switchin between channels occurs at the com
pletion of each sweep. This operatin mode is useful when
viewin both input si nals at sweep rates of 1 millisecond/
division or faster.
CHOP iChopped): The dual-trace crt display alternates
between the CH1 and CH2 Input si nals at a fixed rate of
about 50 kHz. This mode is useful when viewin input
si nals at sweep rates of 0.5 millisecond/'division or slower.
ADD: Crt display is the al ebraic sum of the si nals
applied to the CHI (X) and CH2 (V> INPUT connectors
(CHI plus CH2). When the PULL: INVERT control is
pulled out. the CH2 input si nal is inverted providin a
difference display of si nals applied to the CH 1 and CH2
INPUT connectors (CHI minus CH2).
HORIZONTAL SWEEP CONTROLS (FIGURE 7)
21. POSITION-Controls horizontal positionin of the
crt display, except in the X-Y mode of operation when the
CHI (X) POSITION control provides horizontal positionin .
22. SEC/DIV-Selects the calibrated sweep rate of the
sweep enerator circuit The CAL (Variable) control must
be in its CALibrated detent position for the indicated time
base sweep rate. Fi ure 7. Location of horizontal deflaction system controls.
REV A SEP 1979 305 Operators 11