Bradley 233 User manual

BRADLEY
1^ electronics j
INSTRUCTION MANUAL

u
PERIOD . WiO
c«. -<1— CM, * cAi ;
Ig?
t «» •;« »•■» — ' - - • , «
tt l # '#
5^IP^ S s| "S
S»«» PNW fi M s««
CltHi
m
,>8 10 -1
m m
Pa< S«ri4d
III.
^jjjj^
PULSE OEiMEP^ATOSi ^33
amplitude offset
•'
s ?-s j
AK^LITWK
A 8
rrrL ari
.fSmv-:^, . riH-32-j ,
-"■'"•"^ ' , « # I f rtiTTii' 2i
I E,- .1
m
m
G. S. E. BRADLEY LTD.
Electral House, Neasden Lane, London, N,W.10
Telephone: 01 ^50 TBII Telex: 25583

AMENDMENT RECORD SHEET
Incorporation of an Amendment List in this publication is to be recorded by
signing in the appropriate column and inserting the date of making the amend
ments.
A. L. AMENDED BY DATE
Although every care has been taken to ensure that the information contained in
this manual is accurate at the time of going to press, continuous development
may result in equipment changes and consequent inaccuracies in the Manual.
The Company reserves the right to institute such changes as and when necessary
without prior notification.

Reproduction of this document, or any part of it, without written permission
from G. & E. Bradley Ltd., is prohibited.
GUARANTEE
We will make good by repair or replacement any defects in products of our
manufacture not caused by wear and tear, accident, mis-use or neglect,
provided.
(1) that such defects are brot^ht to our notice not later than 12 months
from the date the goods were first despatched and
(2) that no unauthorized repair or replacement has been previously carried
out or attempted. We do not guarantee the products of other
manufacturers which form part of the goods of our manufacture, but
will pass on to our customer the full benefits we have received in
repsect of guarantees offered by such other manufacturers in respect
of their goods.
This guarantee is given in lieu of any warranty implied by statute or otherwise,
and our liability thereunder is expressly limited to the cost of the repair or
replacement made by us or to our order.
G. and E. Bradley Limited,
Electral House,
Neasden Lane,
London, N. W. 10.

CONTENTS
SECTION 1
1.1
INTRODUCTION
Performance
Page
1
SECTION 2
SPECIFICATION
SECTION 3 OPERATING INSTRUCTIONS
3.1 Installation
3. 2 Push Buttons
3. 3 Rotary Switches
3.4 Functional Description
3.5 'A' Functions
3. 6 'B' Functions
3. 7 Output Functions
SECTION 4 TECHNICAL DESCRIPTION
4.1 Timing Section
4. 2 Output Section
4.3 Power Supplies
SECTION 5 SERVICING AND ADJUSTMENTS
5.1 General
5.2 Mechanical Details
5. 3 Test Equipment
5.4 Power Supplies
5. 5 DC Voltage Test
5. 6 Input and Delay Functions
5.7 Timing
5. 8 Pulse Shape
5. 9 Offset Zero Check
13
13
18
19
21
21
21
21
21
22
23
24
25
26
SECTION 6
PARTS LIST
27
(ill)

LIST OF ILLUSTRATIONS
FRONTISPIECE
FIG. A and B
FIG. 1
FIG. 2
FIG. 3
FIG. 4
FIG. 5
FIG. 6
FIG. 6 (a)
FIG. 6 (b)
FIG. 6 (c)
FIG. 7
FIG. 8
FIG. 9
FIG. 10
Showing Advantage of Source Termination
Showing ECL Logic Circuit
Showing Logic Levels of ECL Gate
Multi-Vibrator Waveforms
Monostable Waveforms
Differentiator Waveforms
Timing Circuit
Period Switch Arrangement
Delay A + B, Width A + B. Switch Arrangement
Delay/Period. Switch Arrangement
Output Circuit
Power Supplies
System Output Circuit
Printed Circuit Board
(iv)

SECTION 1
INTRODUCTION
1.1 PERFORMANCE
The Bradley 233 twin channel pulse generator provides 0. 5Hz to 50MHz at up to 10 volts
positive or negative into 50fi.
Resistive or reactive loads of any magnitude may be driven. The 50n source impedance
('back match') at the generator will always produce a true 50fi source at the end of the cable.
The internal 50J2 can be switched out to provide full 10 volts into a 5052 external load.
Output Baseline offset provides any pulse amplitude from 0. 5 volts to 10 volts within the
limits ±10 volts. The parallel/serial delay allows pulse positions to be adjusted independ
ently or in groups.
The internal sum facility allows the two outputs to be summed without reduction in amplitude
or refelction in the interconnecting cables. This facility provides stepped or super-imposed
pulses up to 20 volts maximum amplitude.
Other features of the 233 are the internal burst facility by using the B delay generator as an
oscillator to be gated by the A width. The adjustable level control and slope selection per
mits triggering off any point on the input waveform. This operates down to zero frequency
whether on external trigger, gate or external width. A Trigger Indicator lights when the
input is correctly triggered.
Simplicity of operation is provided by the square-wave facility which eliminates the need to
adjust the delay and width controls.
The B period oscillator can be free-run independently of the A section thus providing
virtually two pulse generators in one instrument.
1 -

2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12
2.13
2.14
2.15
2.16
2.17
2.18
Repetition Rate
External Input
Manual
Trigger Light
Pre-pulse Output
Delay and Width
Configurations
Internal Burst
Pulse Delay
Pulse Width
Timing Jitter
Timing Drift
Output Configurations
Output Amplitude
Polarity
Baseline Offset
Rise and Fall Times
Waveform Aberration
Output Protection
SECTION 2
SPECIFICATION
0. 5Hz to 50MHz (8 ranges).
DC coupled. Sensitivity 0.4V peak to peak. Minimum pulse width
5ns. Slope selection. Level variation ±4V. Maximum signal 50V
peak. Trigger, gate and external width modes available.
Single cycle, burst and d. c. level or slope modes available from
front panel push button.
Indicates correct level setting when an external input is supplied,
whether used for triggering or gating. Single flash when manual
button is depressed.
Minimum +2V pulse from 50 ohm source. Risetime less than 5ns.
Occurs less than 20ns after triggering from an external source.
Width about 250ns at low frequency reducing automatically to
approximately 10ns at 50MHz.
Two delay plus width chains. May be driven in parallel from the
internal or external period signal, or in series, in which case the
B delay triggers off the trailing edge of the A width.
B delay converts to a period oscillator, gated by width A.
20ns to Is. (Pre-pulse to Main pulse).
10ns to Is. Maximum duty cycle 50% at minimum vernier
increasing to 80% at maximum vernier.
Less than 0.1%. / V ' "f ^ 6 ' ^ ^
Approximately 0.1%/°C.
Two independent output channels. Each can be driven from A and/
or B pulse width or period signal. Each has polarity and comple
ment selection, independent amplitude and offset controls.
Continuously variable 0. 5V to lOV into 500. Internal summation
controlled by push button. Outputs add algebraically into output 2
and output 1 becomes non-operative.
Positive or negative.
0 to -lOV (Positive pulse).
0 to +10V (Negative pulse)
5ns typical.
Less than ±5% at amplitude greater than 2V (with 500 termination).
Short circuit and overload protected.
- 3 -

2.19
2. 20
2. 21
Power Supplies
Temperature Ranges
Dimensions
100-125V or 200-250V. 50/60Hz. Approximately 35VA. All
supplies regulated.
Operation 0 to 50°C
Storage -10 to+60°C.
2.22
Weight
For Rack Mounting
Height: 90mm (3.1/2")
Width: 310mm (12.1/4")
Depth: 280mm (11")
5.5kg (121b).
Overall - includes feet Handles and
Controls.
115mm (4.1/2")
332mm (13.1/8")
322mm (12. 3/4")
- 4

SECTION 3
OPERATING INSTRUCTIONS
3.1 INSTALLATION
1. Check that the rear panel voltage selector switch is set correctly for the supply voltage.
2. Fuse ratings: for 200/250V operation - 0. 5A (supplied)
for 100/125V operation - lA.
3. Supply connections
Brown - Line
Blue - Neutral
Green/yellow - Earth
3.2 PUSHBUTTONS
1. The legend above any push-button refers to the function obtained when the button is in.
2. Black buttons occur in interactive groups, and normally only one button should be in.
3. White buttons are mechanically independent, and the legend below a button refers to
the function obtained when the button is out. It is screened in yellow as a reminder.
4. The red button has a spring-return action.
3.3 ROTARY SWITCHES
1. On all time switches the nomimal value of the switch setting is obtained when the small
concentric vernier control is fully anti-clockwise in the 'CAL' position. When the
vernier is turned clockwise the time increases until it overlaps the next greater range
setting; or on the longest range, overlaps a value ten times greater than the range
setting.
2. Stable pulses can be guaranteed only when the delay and width monostables are not
"counting down". It is important, therefore, to keep both delay and width of a pulse
somewhat less than the period. If the delay is not required, set it to lOnsec.
3. Jitter, or at high frequencies, moding can be caused by any delay or width monostables
counting down. It is good practice to keep all unused delay or width contols set to
lOnsec.
4. On the output amplitude controls the nominal value of the switch setting is obtained
with the vernier fully clockwise in the 'CAL' position. The vernier reduces the
amplitude until it overlaps the next smaller range setting, or on the lowest range,
until it is less than 0. 5V.
3.4 FUNCTIONAL DESCRIPTION
1. A Section
This section determines the pulse rate for the rest of the unit. On "Free Run" and
"Ext Gate" the rate depends on the settings of the PERIOD switch and vernier. On