Wavetek 39A Service Manual

MAINTENANCE MANUAL

Model 39A

40MHz Arbitrary
Waveform Generator

October 2005 - Issue 1

This document contains information proprietary to
Wavetek and is provided solely for instrument
operation and maintenance. The information in this
document may not be duplicated in any manner
without the prior approval in writing from Wavetek.

Wavetek-Datron
Test and Measurement Division

Hurricane Way
Norwich
Norfolk NR6 6JB, U.K.

Tel: [phone]
Fax: [phone]

Table of Contents

Specifications 2

Safety 10

Installation 11

General 12

Circuit Descriptions 13

Calibration 18

Parts List 21

Component Layouts 29

Circuit Diagrams 31

1

Note: This specification covers the whole series which includes 2- and 4- channel instruments;

the interchannel specifications only apply to the multi-channel instruments.

Specifications apply at 18−28ºC after 30 minutes warm−up, at maximum output into 50Ω

WAVEFORMS

Standard Waveforms

Sine, square, triangle, DC, positive ramp, negative ramp, sin(x)/x, pulse, pulse train, cosine,
haversine and havercosine.

Sine, Cosine, Haversine, Havercosine

Range: 0.1mHz to 16 MHz

Resolution: 0.1mHz or 7 digits

Accuracy: 10 ppm for 1 year

Temperature Stability: Typically <1 ppm/ºC.

Specifications

Output Level:

Harmonic Distortion: <0.1% THD to 100kHz; <–65dBc to 20kHz

<–50dBc to 1MHz,

Non−harmonic Spurii:

Square

Range: 1mHz to 16MHz

Resolution: 1mHz (4 digits)

Accuracy: ± 1 digit of setting

Output Level:

Rise and Fall Times: <25ns

Triangle

Range: 0.1mHz to 100kHz

Resolution: 0.1mHz or 7 digits

2.5mV to 10Vp−p into 50Ω

<−35dBc to 10MHz

<−30dBc to 16MHz

<–65dBc to 1MHz, <–65dBc + 6dB/octave 1MHz to 16MHz

2.5mV to 10Vp−p into 50Ω

Accuracy: 10 ppm for 1 year

Output Level:

Linearity Error: <0.1% to 30 kHz

Ramps and Sin(x)/x

Range: 0.1mHz to 100kHz

Resolution: 0.1mHz (7 digits)

Accuracy: 10 ppm for 1 year

Output Level:

Linearity Error: <0.1% to 30 kHz

2

2.5mV to 10Vp−p into 50Ω

2.5mV to 10Vp−p into 50Ω

Pulse and Pulse Train

Output Level: 2.5mV to 10Vp−p into 50Ω

Rise and Fall Times: <25ns

Period:

Range: 100ns to 100s
Resolution: 4-digit
Accuracy: ±1 digit of setting

Delay:

Range: −99.99s to +99.99s
Resolution: 0.002% of period or 25ns, whichever is greater

Width:

Range: 25ns to 99.99s
Resolution: 0.002% of period or 25ns, whichever is greater

Note that the pulse width and absolute value of the delay may not exceed the pulse period at any
time.

Pulse trains of up to 10 pulses may be specified, each pulse having independently defined width,
delay and level. The baseline voltage is separately defined and the sequence repetition rate is set
by the pulse train period.

Arbitrary

Up to 100 user defined waveforms may be stored in the 256K point non−volatile RAM.
Waveforms can be defined by front panel editing controls or by downloading of waveform data via
RS232 or GPIB.

Waveform Memory Size: 64k points per channel. Maximum waveform size is 64k

Vertical Resolution: 12 bits

Sample Clock Range: 100mHz to 40MHz

Resolution: 4 digits

Accuracy: ± 1 digit of setting

Sequence

Up to 16 waveforms may be linked. Each waveform can have a loop count of up to 32,768.

A sequence of waveforms can be looped up to 1,048,575 times or run continuously.

Output Filter

Selectable between 16MHz Elliptic, 10MHz Elliptic, 10MHz Bessel or none.

points, minimum waveform size is 4 points

3

OPERATING MODES
Triggered Burst

Each active edge of the trigger signal will produce one burst of the waveform.

Carrier Waveforms: All standard and arbitrary
Maximum Carrier Frequency: The smaller of 1MHz or the maximum for the selected

Number of Cycles: 1 to 1,048,575

Trigger Repetition Rate: 0.005Hz to 100kHz internal

Trigger Signal Source: Internal from keyboard, previous channel, next channel or

External from TRIG IN or remote interface.

waveform.
40Msamples/s for ARB and Sequence.

dc to 1MHz external.

trigger generator.

Gated

Sweep

Trigger Start/Stop Phase:

Waveform will run while the Gate signal is true and stop while false.

Carrier Waveforms: All standard and arbitrary.

Maximum Carrier Frequency: The smaller of 1MHz or the maximum for the selected

Trigger Repetition Rate: 0.005Hz to 100kHz internal

Gate Signal Source: Internal from keyboard, previous channel, next channel or

Gate Start/Stop Phase:

Frequency sweep capability is provided for both standard and arbitrary waveforms. Arbitrary
waveforms are expanded or condensed to exactly 4096 points and DDS techniques are used to
perform the sweep.

Carrier Waveforms: All standard and arbitrary except pulse, pulse train and sequence.

± 360° settable with 0.1° resolution, subject to waveform
frequency and type.

waveform.

dc to 1MHz external.

trigger generator.

External from TRIG IN or remote interface.

± 360° settable with 0.1° resolution, subject to waveform
frequency and type.

40Msamples/s for ARB and Sequence.

4

Sweep Mode: Linear or logarithmic, triggered or continuous.

Sweep Direction: Up, down, up/down or down/up.

Sweep Range: From 1mHz to 16 MHz in one range. Phase continuous.

Independent setting of the start and stop frequency.

Sweep Time: 30ms to 999s (3 digit resolution).

Marker: Variable during sweep.

Sweep Trigger Source: The sweep may be free run or triggered from the following

sources: Manually from keyboard. Externally from TRIG IN input or
remote interface.

Sweep Hold: Sweep can be held and restarted by the HOLD key.

Multi channel sweep: Any number of channels may be swept simultaneously but the

sweep parameters will be the same for all channels. Amplitude,
Offset and Waveform can be set independently for each channel.

Tone Switching

Capability provided for both standard and arbitrary waveforms. Arbitrary waveforms are expanded
or condensed to exactly 4096 points and DDS techniques are used to allow instantaneous
frequency switching.

Carrier Waveforms: All waveforms except pulse, pulse train and sequence.

Frequency List: Up to 16 frequencies from 1mHz to 10MHz.

Trigger Repetition Rate: 0.005Hz to 100kHz internal

Source: Internal from keyboard, previous channel, next channel or trigger

Tone Switching Modes:

Gated:

The tone is output while the trigger signal is true and stopped, at the

dc to 1MHz external.

Usable repetition rate and waveform frequency depend on the tone
switching mode.

generator.

External from TRIG IN or remote interface.

end of the current waveform cycle, while the trigger signal is false.
The next tone is output when the trigger signal is true again.

Triggered:

The tone is output when the trigger signal goes true and the next

tone is output, at the end of the current waveform cycle, when the
trigger signal goes true again.

FSK: The tone is output when the trigger signal goes true and the next

tone is output, immediately, when the trigger signal goes true again.

Using 2 channels with their outputs summed together it is possible to generate DTMF test
signals.

Trigger Generator

Internal source 0.005 Hz to 100kHz square wave adjustable in 10us steps. 3 digit resolution.
Available for external use from any SYNC OUT socket.

OUTPUTS

Main Output - One for each channel

Output Impedance:

Amplitude:

50Ω

5mV to 20Vp−p open circuit (2.5mV to 10Vp−p into 50Ω). Amplitude
can be specified open circuit (hi Z) or into an assumed load of 50Ω or
600Ω in Vpk−pk, Vrms or dBm.

Amplitude Accuracy:

Amplitude Flatness: ±0.2dB to 200 kHz; ±1dB to 10 MHz; ±2.5dB to 16 MHz.

DC Offset Range:

DC Offset Accuracy: Typically 3% ±10mV, unattenuated.

Resolution: 3 digits or 1mV for both Amplitude and DC Offset.

2% ±1mV at 1kHz into 50Ω.

±10V.DC offset plus signal peak limited to ±10V from 50Ω.

5

Sync Out - One for each channel

Multifunction output user definable or automatically selected to be any of the following:

Waveform Sync:

(all waveforms) A square wave with 50% duty cycle at the main waveform frequency, or

a pulse coincident with the first few points of an arbitrary waveform.

Position Markers:

(Arbitrary only) Any point(s) on the waveform may have associated marker bit(s) set

high or low.

Burst Done: Produces a pulse coincident with the last cycle of a burst.

Sequence Sync: Produces a pulse coincident with the end of a waveform sequence.

Trigger: Selects the current trigger signal. Useful for synchronizing burst or

gated signals.

Sweep Sync: Outputs a pulse at the start of sweep to synchronize an oscilloscope or

recorder.

Phase Lock Out: Used to phase lock two generators. Produces a positive edge at the 0°

phase point.

Output Signal Level:

Cursor/Marker Out

Adjustable output pulse for use as a marker in sweep mode or as a cursor in arbitrary waveform
editing mode. Can be used to modulate the Z−axis of an oscilloscope or be displayed on a
second ‘scope channel.

Output Signal Level: Adjustable from nominally 2V to 14V, normal or inverted; adjustable

Output Impedance:

INPUTS
Trig In

Frequency Range:

Signal Range: Threshold nominally TTL level; maximum input ±10V.

Minimum Pulse Width: 50ns, for Trigger and Gate modes; 50us for Sweep mode.

Polarity: Selectable as high/rising edge or low/falling edge.

Input Impedance:

Modulation In

TTL/CMOS logic levels from typically 50Ω.

width as a cursor.

600Ω typical

DC − 1MHz.

10kΩ

Sum In

6

Frequency Range: DC – 100kHz.

Signal Range:

SCM: Approximately ± 1Vpk for maximum output.

Input Impedance:

Frequency Range:

Signal Range:

Input Impedance:

VCA: Approximately 1V pk−pk for 100% level change at maximum
output.

Typically 1 kΩ.

DC − 8 MHz.

Approximately 2 Vpk−pk input for 20Vpk−pk output.

Typically 1kΩ.

Hold

Holds an arbitrary waveform at its current position. A TTL low level or switch closure causes the
waveform to stop at the current position and wait until a TTL high level or switch opening which
allows the waveform to continue. The front panel MAN HOLD key or remote command may also
be used to control the Hold function. While held the front panel MAN TRIG key or remote
command may be used to return the waveform to the start. The Hold input may be enabled
independently for each channel.

Input Impedance:

10kΩ

Ref Clock In/Out

Set to Input: Input for an external 10MHz reference clock. TTL/CMOS threshold

level.

Set to Output: Buffered version of the internal 10MHz clock. Output levels nominally

1V and 4V from 50Ω.

Set to Phase Lock: Used together with SYNC OUT on a master and TRIG IN on a slave to

synchronise (phase lock) two separate generators.

INTER-CHANNEL OPERATION

Inter-channel Modulation:

The waveform from any channel may be used to Amplitude Modulate (AM) or Suppressed Carrier
Modulate (SCM) the next channel. Alternatively any number of channels may be Modulated (AM
or SCM) with the signal at the MODULATION input socket.

Carrier frequency: Entire range for selected waveform.

Carrier waveforms: All standard and arbitrary waveforms.

Modulation Types:

AM: Double sideband with carrier.

SCM: Double sideband suppressed carrier.

Modulation source: Internal from the previous channel.

External from Modulation input socket.

The external modulation signal may be applied to any number of

channels simultaneously.

Frequency Range: DC to >100 kHz.

Internal AM:

Depth: 0% to 105%

Resolution: 1%.

Carrier Suppression
(SCM):

External Modulation
Signal Range:

SCM: Approximately ± 1Vpk for maximum output.

> −40dB.

VCA: Approximately 1V pk−pk for 100% level change at maximum
output.

7

Inter-channel Analog Summing:

Waveform Summing sums the waveform from any channel into the next channel.
Alternatively any number of channels may be summed with the signal at the SUM input socket.

Carrier frequency: Entire range for selected waveform.

Carrier waveforms: All standard and arbitrary waveforms.

Sum source: Internal from the previous channel.

External from SUM IN socket.

Frequency Range: DC to >8MHz.

External Signal Range:

Inter-channel Phase locking:

Two or more channels may be phase locked together. Each locked channel may be assigned a
phase angle relative to the other locked channels. Arbitrary waveforms and waveform sequences
may be phase locked but certain constraints apply to waveform lengths and clock frequency
ratios. With one channel assigned as the Master and other channels as Slaves a frequency
change on the master will be repeated on each slave thus allowing multi−phase waveforms at the
same frequency to be easily generated.

DDS waveforms are those with 7 digits of frequency setting resolution, while Non−DDS
waveforms have 4 digits

Phase Resolution:

DDS waveforms: 0.1 degree

Non−DDS waveforms:

Phase Error:

All waveforms: <±10ns

The signals from the REF IN/OUT socket and the SYNC OUT socket can be used to phase lock
two instruments where more than 4 channels are required.

Inter-channel Triggering:

Approximately 5Vpk−pk input for 20Vpk−pk output.

0.1 degree or 360 degrees/number of points whichever is the greater.

Any channel can be triggered by the previous or next channel.

The previous/next connections can be used to ’daisy chain’ a trigger signal from a ‘start’ channel,
through a number of channels in the ‘chain’ to an ‘end’ channel. Each channel receives the trigger
out signal from the previous (or next) channel, and drives its selected trigger out to the next (or
previous) channel. The ‘end’ channel trigger out can be set up to drive the ‘start’ channel, closing
the loop.

In this way, complex and versatile inter−channel trigger schemes may be set up. Each channel
can have its trigger out and its output waveform set up independently. Trigger out may be
selected from Waveform End, Position Markers, Sequence Sync or Burst Done.

Using the scheme above it is possible to create a sequence of up to 64 waveform segments,
each channel producing up to 16 segments and all channels being summed to produce the
complete waveform at the output of channel 4.

INTERFACES

Full remote control facilities are available through the RS232 or GPIB interfaces.

RS232:

IEEE−488:

Variable Baud rate, 9600 Baud maximum. 9−pin D−connector.

Conforms with IEEE488.1 and IEEE488.2

8

GENERAL

Display: 20 character x 4 row alphanumeric LCD.

Data Entry: Keyboard selection of mode, waveform etc.; value entry direct by

numeric keys or by rotary control.

Stored Settings:

Size: 3U (130mm) height; 350mm width (2 and 4 channels),

Weight: 7.2 kg. (16 lb), 2 and 4 channels; 4.1kg (9lb) 1 channel.

Power: 230V, 115V or 100V nominal 50/60Hz, adjustable internally;

Operating Range:

Storage Range:

Environmental: Indoor use at altitudes up to 2000m, Pollution Degree 2.

Options: 19 inch rack mounting kit.

Safety:

EMC:

Up to 9 complete instrument set−ups may be stored and recalled
from battery−backed memory. Up to 100 arbitrary waveforms can
also be stored independent of the instrument settings.

212mm (½−rack) single channel; 335mm long.

operating range ±14% of nominal; 100VA max. for 4 channels,
75VA max. for 2 channel, 40VA max. for 1 channel. Installation
Category II.

+5°C to 40°C, 20−80% RH.

−20°C to + 60°C.

Complies with EN61010−1.

Complies with EN50081−1 and EN50082−1.

9

Safety

This generator is a Safety Class I instrument according to IEC classification and has been
designed to meet the requirements of EN61010−1 (Safety Requirements for Electrical Equipment
for Measurement, Control and Laboratory Use). It is an Installation Category II instrument
intended for operation from a normal single phase supply.

This instrument has been tested in accordance with EN61010−1 and has been supplied in a safe
condition. This instruction manual contains some information and warnings which have to be
followed by the user to ensure safe operation and to retain the instrument in a safe condition.

This instrument has been designed for indoor use in a Pollution Degree 2 environment in the
temperature range 5°C to 40°C, 20% − 80% RH (non−condensing). It may occasionally be
subjected to temperatures between +5° and −10°C without degradation of its safety. Do not
operate while condensation is present.

Use of this instrument in a manner not specified by these instructions may impair the safety
protection provided. Do not operate the instrument outside its rated supply voltages or
environmental range.

WARNING! THIS INSTRUMENT MUST BE EARTHED

Any interruption of the mains earth conductor inside or outside the instrument will make the
instrument dangerous. Intentional interruption is prohibited. The protective action must not be
negated by the use of an extension cord without a protective conductor.

When the instrument is connected to its supply, terminals may be live and opening the covers or
removal of parts (except those to which access can be gained by hand) is likely to expose live
parts. The apparatus shall be disconnected from all voltage sources before it is opened for any
adjustment, replacement, maintenance or repair.

Any adjustment, maintenance and repair of the opened instrument under voltage shall be avoided
as far as possible and, if inevitable, shall be carried out only by a skilled person who is aware of
the hazard involved.

If the instrument is clearly defective, has been subject to mechanical damage, excessive moisture
or chemical corrosion the safety protection may be impaired and the apparatus should be
withdrawn from use and returned for checking and repair.

Make sure that only fuses with the required rated current and of the specified type are used for
replacement. The use of makeshift fuses and the short−circuiting of fuse holders is prohibited.

This instrument uses a Lithium button cell for non−volatile memory battery back−up; typical life is
5 years. In the event of replacement becoming necessary, replace only with a cell of the correct
type, i.e. 3V Li/Mn0
in accordance with local regulations; do not cut open, incinerate, expose to temperatures above
60°C or attempt to recharge.

Do not wet the instrument when cleaning it and in particular use only a soft dry cloth to clean the
LCD window. The following symbols are used on the instrument and in this manual:−

20mm button cell type 2032. Exhausted cells must be disposed of carefully

2

Caution −refer to the accompanying documentation,
incorrect operation may damage the instrument.

10

l

terminal connected to chassis ground.

mains supply OFF.

mains supply ON.

alternating current.

Mains Operating Voltage

Check that the instrument operating voltage marked on the rear panel is suitable for the local
supply. Should it be necessary to change the operating voltage, proceed as follows:

1) Disconnect the instrument from all voltage sources.

2) Remove the screws which retain the top cover and lift off the cover.

3) Change the transformer connections following the diagram below.

4) Refit the cover and the secure with the same screws.

5) To comply with safety standard requirements the operating voltage marked on the rear panel
must be changed to clearly show the new voltage setting.

6) Change the fuse to one of the correct rating, see below.

Installation

Fuse

Ensure that the correct mains fuse is fitted for the set operating voltage. The correct mains fuse
types are:

To replace the fuse, disconnect the mains lead from the inlet socket and withdraw the fuse drawer
below the socket pins. Change the fuse and replace the drawer.

The use of makeshift fuses or the short−circuiting of the fuse holder is prohibited.

Mains Lead

When a three core mains lead with bare ends is provided it should be connected as follows:−

Any interruption of the mains earth conductor inside or outside the instrument will make the
instrument dangerous. Intentional interruption is prohibited. The protective action must not be
negated by the use of an extension cord without a protective conductor.

Mounting

This instrument is suitable both for bench use and rack mounting. It is delivered with feet for
bench mounting. The front feet include a tilt mechanism for optimal panel angle.

for 230V operation connect the live (brown) wire to pin 15
for 115V operation connect the live (brown) wire to pin 14
for 100V operation connect the live (brown) wire to pin 13

for 230V operation: 250 mA (T) 250V HRC
for 100V or 115V operation: 500 mA (T) 250V HRC

Brown

Blue

Green / Yellow

WARNING! THIS INSTRUMENT MUST BE EARTHED

Mains Live

−
Mains Neutral

−
Mains Earth

−

A rack kit for mounting in a 19” rack is available from the Manufacturers or their overseas agents.

11

Service Handling Precautions

Service work or calibration should only be carried out by skilled engineers. Please note the
following points before commencing work.

Most of the integrated circuits are CMOS devices and care should be taken when handling to
avoid damage by static discharge. Also most devices are surface mounted miniature components
with very fine leads on small pitches. These components must be removed and replaced with
great care to avoid damage to the PCB. It is essential that only the proper tools and soldering
equipment as recommended for surface mount components are used.

The decoupling capacitors associated with the integrated circuits are surface mounted on the
solder side of the PCB.

Dismantling the Instrument

Disconnect the instrument from all voltage sources before it is opened for adjustment or repair. If
any adjustment or repair of the opened instrument is inevitable it shall be carried out only by a
skilled person who is aware of the hazards involved.

General

WARNING!

1. Remove the six screws retaining the top cover.

2. The rear panel may be removed as follows. Disconnect the grey ribbon cable from PJ6 on
the GPIB PCB. Invert the instrument and remove the three screws securing the rear panel
and the nuts securing the 9-way RS232 connector to the rear panel. The panel may now
be tilted back to allow access. If the panel is to be completely removed the connectors
must be removed from PJ3, PJ7, PJ8 and PJ11, the blue and brown wires disconnected
from the mains inlet filter and the blue and brown wires unsoldered from the mains
transformer. Cut the ties holding the cable assembly to the side instrument chassis. The
panel is then completely free of the instrument.

3. The front panel assembly may be removed as follows. Remove the connectors from PJ2,
PJ4, PJ12, PJ13 and PJ200 and desolder the screened cable from PJ202. Remove the
two nuts and bolts in the sides and two screws in the bottom of the instrument securing
the front panel assembly. The panel may now be drawn clear of the instrument.

4. Main pcb removal. Remove all connectors from the pcb and desolder the screened cable
from PJ10. Tilt the rear panel away as in 2 above. Remove six screws and lift away the
main pcb. When re-assembling the instrument ensure that all fixings use the correct
fastenings.

12

T

T

T

T

A

A

A

A

A

T

V

V

A

AmpA

General

The following sections should be read with reference to the block diagram and the circuit
diagrams.

rig Out From

Previous Channel

rig Out From

Next Channel

Common
Remote
Control
GPIB/

Common
Hold In

Common
Cursor/
Marker
Out

DC Offset

RS232

Common
CPU

Control
DAC,s

Common
Ext

rig

Circuit Descriptions

Sync
Out

rig Out

Lock Clock In/Out To

Waveform
FPGA

INT

RIG

PLL

10MHz
CLK

Common

CA

In

Common
SUM
In

SUM Out
From Previous

Other Channels

Waveform
RAM

CA

SUM

0-50dB

ttenuator

12 bit
DAC

Common
CLK
In/Out

mplitude

Control

mp

16MHz
Elliptic
Filter

Bessel
Filter

10MHz
Elliptic
Filter

Zero Crossing
Comparator

ttenuators

Sum Out

DC
Offset

Output

mp

mp

Main
Out

ttenuators

Principles of Operation

The instrument operates in one of two different modes depending on the waveform selected.
DDS mode is used for sine, cosine, haversine, triangle, sinx/x and ramp waveforms. Clock
Synthesis mode is used for square, pulse, pulse train, arbitrary and sequence.

In both modes the waveform data is stored in RAM. As the RAM address is incremented the
values are output sequentially to a Digital-to-Analogue Converter (DAC) which reconstructs the
waveform as a series of voltages steps which are subsequently filtered before being passed to
the main output connector.

The main difference between DDS and Clock Synthesis modes is the way in which the addresses
are generated for the RAM and the length of the waveform data.

Simplified Block Diagram

13

Clock Synthesis Mode

In Clock Synthesis mode the addresses are always sequential (an increment of one) and the
clock rate is adjusted by the user in the range 40MHz to 0.1Hz. The frequency of the waveform is
clock frequency ÷ waveform length, thus allowing short waveforms to be played out at higher
repetition rates than long waveforms, e.g. the maximum frequency of a 4 point waveform is
40e6÷4 or 10MHz but a 1000 point waveform has a maximum frequency of40e6÷1000

Arbitrary waveforms have a user defined length of 4 to 65536 points. Squarewaves use a fixed
length of 2 points and pulse and pulse train have their length defined by the user selected period
value.

DDS Mode

In DDS mode (Direct Digital Synthesis) all waveforms are stored in RAM as 4096 points. The
frequency of the output waveform is determined by the rate at which the RAM addresses are
changed. The address changes are generated as follows:

or 40kHz.

The RAM contains the amplitude values of all the individual points of one cycle (360º) of the
waveform; each sequential address change corresponds to a phase increment of the waveform of
360º/4096. Instead of using a counter to generate sequential RAM addresses, a phase
accumulator is used to increment the phase.

On each clock cycle the phase increment, which has been loaded into the phase increment
register by the CPU, is added to the current result in the phase accumulator; the 12 most
significant bits of the phase accumulator drive the lower 12 RAM address lines, the upper 4 RAM
address lines are held low. The output waveform frequency is now determined by the size of the
phase increment at each clock. If each increment is the same size then the output frequency is
constant; if it changes, the output frequency changes as in sweep mode.

The generator uses a 38 bit accumulator and a clock frequency which is 2

38

x 10-4(~27.4878

MHz); this yields a frequency resolution of 0.1 mHz.

Only the 12 most significant bits of the phase accumulator are used to address the RAM. At a
waveform frequency of F

CLK/4096 (~6.7MHz), the natural frequency, the RAM address increments

at every clock. At all frequencies below this (i.e. at smaller phase increments) one or more
addresses are output for more than one clock period because the phase increment is not big
enough to step the address at every clock. Similarly at frequencies above the natural frequency
the larger phase increment causes some addresses to be skipped, giving the effect of the stored
waveform being sampled; different points will be sampled on successive cycles of the waveform.

14

MPU and Memory

The majority of the digital hardware in the instrument is contained in 3 LSI devices, these being a
MicroProcessor Unit, IC3, and 2 Field Programmable Gate Arrays, IC10 and IC221.

The Z80180 MPU contains an 8 bit Z80 core, 2x16 bit counter-timers, 2x8 bit serial interfaces and
a memory management unit. The MPU is clocked at 12MHz by XTL1.

The MPU provides 20 memory address lines which are used to provide access to a total of 1M
bytes of memory, this comprising a 512k byte EPROM (IC4) and 5 128k byte rams IC5 – 9. The
EPROM is located at address 00000h and extends to 07FFFFh. The top 128k bytes are shared
by IC5 and the selection of ram or EPROM is controlled by the FPGA, IC10. The other 4 rams are
located at addresses 080000h to 0FFFFFh. IC9 is the system ram which contains all the essential
variables and work areas including the software stack. IC5 -8 is the non volatile store for all the
arbitrary waveforms and is not used for any other purpose. The MPU selects between the
memory devices via address decoders located in the FPGA at IC10.

The RS232 interface is provided directly by the MPU and is buffered to the rear panel connector
(PJ1) by IC1 and IC2.

One of the counter-timers provides a constant 0.5ms 'tick' to the MPU which is used to time all
the housekeeping functions, e.g. keyboard scan, knob control, as well as some generator
functions, e.g. frequency sweep. The second counter-timer is not used.

The FPGA, IC10, provides the port select signals to the GPIB board.

Keyboard, LCD and LEDs

The keyboard is interrogated every 10ms. This is done by reading the registers in IC12 and IC13.
If a key is down then one of the transistors Q6-Q13 will be on and the corresponding bits read
from IC12/IC13 will be high. The MPU decodes this to produce a key code which is passed to the
software. Multiple keys down are ignored. IC10 provides the port decode signals for access to
IC12 and IC13.

The knob is connected directly to the FPGA, IC10. This decodes the 4 states of the switches and
increments/decrements a counter. The counter is read and cleared every 10ms and the value and
sign passed to the software.

The 6 LEDs are driven directly from the outputs of IC18 and IC19 which are shift registers loaded
under CPU control by IC10.

The LCD is accessed via a bi-directional 4 bit port in IC10.

FPGA Waveform Generation

The FPGA, IC221, provides the complete waveform generation system including a 38-bit phase
accumulator (for DDS operation), a programmable divide-by-n register (for arbitrary waveform
playback), a 16-segment waveform sequencer, trigger/gate control logic, 20 bit re-loadable burst
counter, multi-instrument phase synchronisation logic and an 8-bit 16 port bi-directional MPU
interface.

Access is provided to the waveform RAM to allow the patterns to be written and the Sync and
Cursor/Marker output signals are generated.

All internal operations of the FPGA are clocked by the signal ARBCLK. Note that if this signal is
interrupted it is possible for the FPGA to become non-functional requiring the FPGA be
completely reset. The clock could be interrupted by a fault condition or by setting the CLOCK
BNC to INPUT and then providing an unacceptable clock. An unacceptable clock is any signal
which overrides the internal clock but produces a replacement which is less than 9MHz or greater
than 10.5MHz. This would happen if, for example, a DC voltage >2V was connected to the clock
input.

15

Trigger Generator

This is created by a counter-timer in IC10. The counter-timer produces a squarewave in the range
100kHz to 0.005Hz. The FPGA, IC221, may be set to use this as the internal trigger.

Power Supply

The transformer has two separate secondaries; one provides ± 15V by IC30 and IC31, the other
provides +5V by low drop-out regulator IC32 and −5V by IC33. The display backlight is driven by
a current source made up of Q22 and associated components and is approximately 150mA. IC34
provides local regulation for the +5V analogue. IC204 provides local regulation for the VCO.
IC226 provides local regulation for the PLL. PJ5 is a test point for the supply rails. Four PCB
mounted fuses protect the transformer secondaries under fault conditions.

Required values measured at PJ5:

pin 1: +5VCPU ± 0.2V
pin 2: 0V

pin 3: −5V ± 0.2V

pin 4: −15V ± 0.6V
pin 5: +5VA ± 0.2V
pin 6: +15V ± 0.6V

Waveform DAC and Filters

IC210 is a high speed 12-bit DAC whose data is latched on the rising edge of DACCLK. The
output current is 20mA fullscale giving 1Vp-p into 50Ω, from 0V to −1V. The DAC has an internal

−1.23V (−1.27V to −1.17V) reference. R218 sets the full-scale output current. An internal control

amplifier mirrors this with respect to the −5V rail.

L201,L202,L203 and associated components form the 16MHz 7-stage elliptic filter. The inductors
are factory set before board assembly and must not be adjusted. L204 provides sinx/x correction
and is adjusted at initial calibration.

L205,L206,L207 and associated components form the 10MHz 7-stage elliptic filter. The inductors
are factory set before board assembly and must not be adjusted. L208 provides sinx/x correction
and is adjusted at initial calibration.

L209, C252 and C253 form a Bessel filter. L209 is also factory preset.

Amplitude Control, Sum and Modulation

IC215 is a 4-quadrant multiplier driven differentially via IC211. The main signal is at M and is 0V
to −1V; a dc reference, M1, of half this is generated by IC200-A. Amplitude is controlled by
IC218-A; with the output set to maximum the voltage at its output is approximately 1V.

External AM is selected by IC214-A and is summed with the amplitude control voltage at the input
of IC218-A.

Sum is selected by IC214-C and the external signal is summed at the multiplier output via its
Z input.

IC212 and IC213 form the sum input attenuator.

Amplifiers and Attenuators

With the amplitude at maximum the signal at the output of the multiplier is approximately 1Vp-p.
IC219 gives a gain of 5.5 to give 5.5Vp-p and IC220 gives a gain of 3.8 to give 20Vp-p.

IC218-B provides DC offset for the main output; when set to maximum, i.e. +10V, IC218-B’s
output will be approximately −10V and its input approximately –3.6V.

Relays RL201 and RL202 select 20dB output attenuators and IC217 selects an intermediate

−10dB attenuator.

16

Zero Crossing Detector

IC201 is a comparator with positive feedback via R203. M is the signal selected by IC211 and M2
is the signals dc mid-point which is buffered by IC200-B. This circuit is used to detect zero
crossing of high frequency DDS waveforms of sine, ramp or triangle and sent to the FPGA.

Control DACs

IC27 is a 12-bit voltage output DAC with internal 2V reference. IC115 provides a bi-polar output of
± 3.3V. IC28 multiplexes the DAC output voltage onto the appropriate hold capacitor. FET input
amplifiers IC29 buffer the voltages on the hold capacitors.

IC208 is a quad 8-bit DAC. IC209D provides a 3.3V reference to give 0 to 3.3V DAC output.
IC209-A, -B and -C give gain and/or offset. VR200 gives coarse adjustment of the multiplier offset
and is only adjusted at initial calibration with the default calibration values present.

The voltage at each DAC output is controlled by the MPU which calculates each value from a
combination of the instrument set up and the calibration constants stored in EEPROM.

Reference Clock

IC105 is an integrated 10MHz voltage controlled crystal oscillator. If an external clock is applied,
C48 is charged up via D5 blocking the internal clock.

Phase-Locked-Loop and VCO

IC203 is a VCO tuned by varicap diodes D209-212. The range is 20MHz to 40MHz for square
and arbitrary waveforms and fixed at 27.48779MHz in the DDS mode. Comparator IC205 gives
TTL output levels.

IC206 is a PLL IC and has internal dividers for both inputs which are set by the MPU. Phase
comparison is done at 3kHz in PLL mode and slightly higher in DDS mode. IC15 is the loop filter
which drives the VCO. LED2 is out when the loop is in lock.

Inputs and Outputs

IC21 is a hex Schmitt; -A, -B, -D and -E are used for the Trig In and Hold In inputs. The Sync
output has four gates in parallel, IC202.

IC23 is an octal 3-state buffer. When Clock In/Out is an output the top four buffers are enabled
and the bottom four disabled. When Clock In/Out is an input the top four buffers are disabled and
the bottom four enabled.

The Zmod output high is set by the three digital signals at the input of IC16-A. IC16-A provides
gain to give a maximum output high of 14V. When Q14 is on, the output is low; when turned off
the output goes high until D2 conducts, clamping output high to the required level.

17

All parameters can be calibrated without opening the case, i.e. the generator offers ‘closed−box’
calibration. All adjustments are made digitally with calibration constants stored in EEPROM. The
calibration routine requires only a DVM and a frequency counter and takes no more than a few
minutes.

The crystal in the timebase is pre−aged but a further ageing of up to ±5ppm can occur in the first
year. Since the ageing rate decreases exponentially with time it is an advantage to recalibrate
after the first 6 month’s use. Apart from this it is unlikely that any other parameters will need
adjustment.

Calibration should be carried out only after the generator has been operating for at least 30
minutes in normal ambient conditions.

Equipment Required

• 3½ digit DVM with 0.25% DC accuracy and 0.5% AC accuracy at 1kHz.

• Frequency counter capable of measuring 10.00000MHz.

The DVM is connected to the MAIN OUT of each channel in turn and the counter to any SYNC
OUT.

Frequency meter accuracy will determine the accuracy of the generator’s clock setting and
should ideally be ±1ppm.

Calibration

Calibration Procedure

The calibration procedure is accessed by pressing the calibration… soft−key on the
UTILITY screen.

The software provides for a 4−digit password in the range 0000 to 9999 to be used to access the
calibration procedure. If the password is left at the factory default of 0000 no messages are
shown and calibration can proceed as described in the Calibration Routine section; only if a
non−zero password has been set will the user be prompted to enter the password.

Setting the Password

On opening the Calibration screen press the password… soft−key to show the password
screen:

Enter a 4−digit password from the keyboard; the display will show the message NEW PASSWORD
STORED! for two seconds and then revert to the UTILITY menu. If any keys other than 0−9
are pressed while entering the password the message ILLEGAL PASSWORD! will be shown.

CALIBRATION SELECTED
Are you sure ?

◊password… tests…◊
◊exit continue◊

ENTER NEW PASSWORD

−−−−

Using the Password to Access Calibration or Change the Password

With the password set, pressing calibration… on the UTILITY screen will now show:

ENTER PASSWORD

----

18

When the correct password has been entered from the keyboard the display changes to the
opening screen of the calibration routine and calibration can proceed as described in the
Calibration Routine section. If an incorrect password is entered the message INCORRECT
PASSWORD! is shown for two seconds before the display reverts to the UTILITY menu.

With the opening screen of the calibration routine displayed after correctly entering the password,
the password can be changed by pressing password... soft−key and following the procedure
described in Setting the Password. If the password is set to 0000 again, password protection is
removed.

The password is held in EEPROM and will not be lost when the memory battery back−up is lost.
In the event of the password being forgotten, contact the manufacturer for help in resetting the
instrument.

Calibration Routine

The calibration procedure proper is entered by pressing continue on the opening Calibration
screen; pressing exit returns the display to the UTILITY menu. Pressing tests… calls a
menu of basic hardware checks used at production test which are self-explanatory. At each step
the display changes to prompt the user to adjust the rotary control or cursor keys, until the
reading on the specified instrument is at the value given. The cursor keys provide coarse
adjustment, and the rotary control fine adjustment. Pressing next increments the procedure to
the next step; pressing CE decrements back to the previous step. Alternatively, pressing exit
returns the display to the last CAL screen at which the user can choose to either save new
values, recall old values or calibrate again.

The first two displays (CAL 00 and CAL 01) specify the connections and adjustment method. The
next display (CAL 02) allows the starting channel to be chosen in multi-channel instruments;
ignore CAL02 in this instrument and step on to CAL03. The subsequent displays, CAL 03 to
CAL 55, permit all adjustable parameters to be calibrated.

The full procedure is as follows:

CAL 03 CH1. DC offset zero. Adjust for 0V ± 5mV.

CAL 04 CH1. DC offset at + full scale. Adjust for + 10V ± 10mV.

CAL 05

CAL 06 CH1. Multiplier zero. Adjust for minimum Volts AC

CAL 07 CH1. Multiplier offset. Adjust for 0V ± 5mV.

CAL 08 CH1. Waveform offset. Adjust for 0V ± 5mV.

CAL 09

CAL 10 CH1. 20dB attenuator Adjust for 1V ± 1mV.

CAL 11 CH1. 40dB attenuator Adjust for 0.1V ± .1mV.

CAL 12 CH1. 10dB attenuator Adjust for 2.236V AC ± 10mV.

CAL 13 CH1. Not used.

CAL 14 CH1. Not used.

CH1. DC offset at − full scale.

CH1. Output level at full−scale

Check for –10V ± 3%

Adjust for 10V ± 10mV.

CAL 15 CH1. Not used.

CAL 55 Clock calibrate Adjust for 10.00000 MHz at SYNC OUT.

Service Adjustments

The following 3 sections contain information about adjustments which are normally done once
only at the factory. These may need to be repeated if a component in the relevant area is
changed.

19

VCO Adjustment

This should not normally be necessary and L6 is sealed at the factory. However if a problem is
suspected or components in this circuit have been changed carry out the following test first.

Set the output to 10MHz squarewave and check that the voltage at TP200.3 is −9.5V to −10.5V.
Check LED 200 is off.

Only if the voltage is outside these limits should L200 be adjusted to −10V ±0.2V. L6 core must
then be resealed again to reduce phase noise caused by mechanical vibration. Use only non­corrosive silicon rubber.

VR200 Adjustment

Not normally necessary. Must only be adjusted with the default calibration values loaded or
CAL07 set to 0128. At CAL07 adjust VR200 for 0Vdc ± 5mV.

Amplitude Flatness

This should not normally be necessary. Set to 20Vpk-pk and use a 50Ohm terminator, frequency
to 100kHz sinewave. Adjust oscilloscope to show exactly 6 divisions. Frequency to 10.00000MHz
and adjust L208 for exactly 6 divisions. Frequency to 10.1MHz and adjust L204 for exactly 6
divisions. These two adjustments should only be done using a high quality oscilloscope with a
bandwidth of at least 100MHz.

Remote Calibration

Calibration of the instrument may be performed over the RS232 or GPIB interface. To completely
automate the process the multimeter and frequency meter will also need to be remote controlled
and the controller will need to run a calibration program unique to this instrument.

The remote calibration commands allow a simplified version of manual calibration to be
performed by issuing commands from the controller. The controller must send the CALADJ
command repeatedly and read the dmm or frequency meter until the required result for the
selected calibration step is achieved. The CALSTEP command is then issued to accept the new
value and move to the next step.

While in remote calibration mode very little error checking is performed and it is the controllers
responsibility to ensure that everything progresses in an orderly way. Only the following
commands should be used during calibration.

WARNING: Using any other commands while in calibration mode may give unpredictable results
and could cause the instrument to lock up, requiring the power to be cycled to regain control.

CALIBRATION <cpd> [,nrf]

START Enter calibration mode; this command must be issued before any other

SAVE Finish calibration, save the new values and exit calibration mode.

ABORT Finish calibration, do not save the new values and exit calibration mode.

CALADJ <nrf> Adjust the selected calibration value by <nrf>. The value must be in the

CALSTEP Step to the next calibration point.

For general information on remote operation and remote command formats, refer to the Instrument
instruction manual remote operation sections.

The calibration control command. <cpd> can be one of three
sub−commands:−

calibration commands will be recognised.

<nrf> represents the calibration password. The password is only required
with CALIBRATION START and then only if a non−zero password has
been set from the instrument’s keyboard. The password will be ignored,
and will give no errors, at all other times.

It is not possible to set or change the password using remote commands.

range −100 to +100. Once an adjustment has been completed and the
new value is as required the CALSTEP command must be issued for the
new value to be accepted.

20

Parts List

PCB ASSY - KEYBOARD (44912-0710)

Part Number Description Position

22224-0010 ENCODER ROT 36 POS W/O DETENT SW1

22226-0101 KEYSWITCH - ALPS SKHHBW K5-12, 20, 21, 30, 31, 48

22226-0150 KEYSWITCH LIGHT GREY K1, 2, 4, 13-19, 22-29, 32-47, 49

23202-1680 RES 680RF W25 MF 50PPM R1-3,5,11,12

23382-2470 RES PS/H 5K0 CERMET MIN VR3

25061-0200 LED - T1 ROUND (3mm) - RED LD1-5,11

35555-3010 PCB - KEYBOARD

43171-2230 CONN ASSY KB/MAIN 34W

PCB ASSY – MAIN (44912-0720)

Part Number Description Position

10366-9701 ADHESIVE MTG PADS 25 x 12MM FOR BATTERY

20613-0006 WASHER (SIL-PAD) TO220 FOR SK200

20613-0007 WASHER (SIL-PAD) TO220 PLAIN FOR SK2

20670-0135 CLIP GP02 FOR PCB MTG H/SINKS FOR SK2-5,200

20670-0310 HEATSINK PCB MTG 38MM PLAIN SK200 FOR IC220

20670-0320 HEATSINK PCB MTG 50MM PLAIN SK2,3,4,5

20670-0340 HEATSINK TO220 CLIP-ON 29DEG/W SK8

22010-0610 BATTERY 3V LITH 20MM BUTTON BATT

22040-0920 BEAD FERRITE – LEADED FB1,200-206

22042-0260 INDUCTOR 2.7UH L208

22042-0261 INDUCTOR 2.07UH BLK L205

22042-0262 INDUCTOR 2.0UH WHT L206

22042-0263 INDUCTOR 1.78UH GRN L207

22042-0271 INDUCTOR 1.545UH RED L209

22042-0290 INDUCTOR 1.2UH L204

22042-0291 INDUCTOR 1.322UH YEL L201

22042-0292 INDUCTOR 1.157UH RED L202

22042-0293 INDUCTOR 1.06UH BLUE L203

22042-0300 INDUCTOR 0.47UH L200

22240-0020 RELAY TYPE 53/5 (24V) RL201,202

22240-0050 RELAY TYPE 47 (24VDC) RL200,203,204,205

22315-0450 FUSE 500mAT SUBMIN PCB MNT FS3,4

22315-0453 FUSE 1.5AT SUBMIN PCB MTG FS1, 2

22573-0041 HEADER 2WAY STR SIL STD/GOLD LK1, 2, TP1, TP201/202

22573-0048 HEADER 3WAY STR SIL STD/GOLD PJ202 (CENTRE PIN REMOVED)

21

PCB ASSY – MAIN (44912-0720) continued/...

Part Number Description Position

22573-0070 HEADER 4WAY STR SIL STD TP200

22573-0202 HEADER 2 WAY STRAIGHT .156P PJ3, 7, 200

22573-0204 HEADER 4 WAY STRAIGHT .156P PJ11/12, PJ13

22573-0206 HEADER 6 WAY STRAIGHT .156P PJ8

22574-0450 SKT 9W R/A D-TYPE (CLIP IN) PJ1

22575-0038 HEADER 6WAY STR SIL STD PJ5

22575-0065 HEADER 20 WAY(2X10) STR SKEL PJ6

22575-0100 HEADER 34 WAY(2X17) STR SKEL PJ2, 4

23105-0010 RES SM0805 1R00F W1 R276

23105-0022 RES SM0805 2R20F W1 R275

23105-0068 RES SM0805 6R80F W1 R274

23105-0100 RES SM0805 10R0F W1 R25

23105-0215 RES SM0805 21R5F W1 R204, 273

23105-0510 RES SM0805 51R0F W1 R200, 237, 238, 239, 244, 253, 278, 300

23105-0620 RES SM0805 62R0F W1 R219

23105-0680 RES SM0805 68R0F W1 R247, 250, 272, 277

23105-0820 RES SM0805 82R0F W1 R269

23105-1100 RES SM0805 100RF W1 R7, 225, 227, 229, 230, 249

23105-1110 RES SM0805 110RF W1 R48-51, 251, 266

23105-1130 RES SM0805 130RF W1 R58, 62

23105-1150 RES SM0805 150RF W1 R201, 213-216

23105-1180 RES SM0805 180RF W1 R220, 294, 309

23105-1215 RES SM0805 215RF W1 R248, 271

23105-1220 RES SM0805 220RF W1 R3, 59, 223, 312

23105-1470 RES SM0805 470RF W1 R36, 37, 252, 281, 293

23105-1510 RES SM0805 510RF W1 R226, 297

23105-1620 RES SM0805 620RF W1 R24, 307

23105-1680 RES SM0805 680RF W1 R311

23105-2100 RES SM0805 1K00F W1 R5,10,27,33,34,56,57,60,61,202,218,228,304-305

23105-2130 RES SM0805 1K30F W1 R268

23105-2150 RES SM0805 1K50F W1 R292

23105-2180 RES SM0805 1K80F W1 R267, 291

23105-2200 RES SM0805 2K00F W1 R222, 231, 287

23105-2220 RES SM0805 2K20F W1 R280

23105-2240 RES SM0805 2K40F W1 R19, 28, 243

23105-2270 RES SM0805 2K70F W1 R18, 22, 26, 232, 299

22

PCB ASSY – MAIN (44912-0720) continued/...

Part Number Description Position

23105-2300 RES SM0805 3K00F W1 R30, 310

23105-2470 RES SM0805 4K70F W1 R23, 282, 288, 289, 290, 295, 296, 298

23105-2510 RES SM0805 5K10F W1 R233, 242, 306

23105-2560 RES SM0805 5K60F W1 R240, 270

23105-3100 RES SM0805 10K0F W1 R1, 2,4,6,11-14,32, 35 55,205,207,209-211,235

23105-3120 RES SM0805 12K0F W1 R217

23105-3150 RES SM0805 15K0F W1 R221, 236, 241, 279

23105-3200 RES SM0805 20K0F W1 R53, 54, 154

23105-3270 RES SM0805 27K0F W1 R206, 212

23105-3330 RES SM0805 33K0F W1 R155

23105-3470 RES SM0805 47K0F W1 R29, 203, 208, 234, 301, 302, 303

23105-3510 RES SM0805 51K0F W1 R17

23105-4100 RES SM0805 100KF W1 R8, 16, 20, 21, 38

23105-4200 RES SM0805 200KF W1 R15

23105-5100 RES SM0805 1M00F W1 R9

23105-6100 RES SM0805 10M0F W1 R45, 52, 224

23202-0039 RES 3R90F W25 MF 50PPM R72

23202-0100 RES 10R0F W25 MF 50PPM R70

23202-0102 RES 10R2F W25 MF 50PPM R262, 265

23202-1240 RES 240RF W25 MF 50PPM R40

23202-1750 RES 750RF W25 MF 50PPM R39

23202-2220 RES 2K20F W25 MF 50PPM R71

23206-0412 RES 41R2F W60 MF 50PPM R260, 261, 263, 264

23206-1200 RES 200RF W60 MF 50PPM R256-259

23222-0047 RES 4R70J W33 MF FUSIBLE R254, 255

23301-0443 RES NETWK SIL 22K X 8 RP1-3

23377-2220 RES PS/H 2K2 CF 10MM VR200

23424-0443 CAP10NZ 1KV CER D10 P5 C70, 71

23427-0268 CAP22PJ 100V CER NPO P2.5 C1, 4, 50, 51, 206, 207

23427-0331 CAP1N0K 63V CER HI K P5 C311

23427-0593 CAP82PG 100V CER NPO P2.5 C233

23427-9205 CAP47PJ 100V CER NPO P2.5 C245, 276, 293, 318

23427-9209 CAP33PJ 100V CER NPO P2.5 C8, 246, 248, 250, 251

23427-9218 CAP 330PK 100V CER MED K P2.5 C253

23428-0082 CAP8P2C 100V CER NPO P2.5 C232, 234, 270, 319

23428-0390 CAP39PG 100V CER N150 P2.5 C240, 242, 244, 252, 254

23

PCB ASSY – MAIN (44912-0720) continued/...

Part Number Description Position

23428-0560 CAP56PG 100V CER N150 P2.5 C239, 247

23428-1100 CAP 100PG 100V CER NPO P2.5 C12, 235, 241, 249

23428-1150 CAP 150PG 100V CER N150 P2.5 C236

23428-1180 CAP 180PG 100V CER N750 P2.5 C238, 243

23461-0015 CAP SM0805 10NK 50V CER X7R C48, 210, 213, 216, 218, 219, 221, 224, 225,

271, 288, 289, 290, 292, 320, 322

23461-0020 CAP SM0805 100NZ 50V CER Y5V C3, 6, 9-11,16-41,52-57,60-63,66,67, 81, 141,

155, 200, 201,203, 204, 205,208, 209,211, 214,
215, 217, 220, 229, 230, 255, 256, 257, 261,
262, 263, 265, 267-269, 272-275, 277-279, 281,
283, 291, 294, 295,300-310, 312-317, 321

23557-0612 CAP 1U0 100V ELEC RE2 P2 C15

23557-0647 CAP 10U 35V ELEC RE2 P2 C2, 5, 13, 14, 42, 43, 76, 77, 79, 212, 264, 266,

280, 282, 285, 286

23557-0658 CAP 100U 25V ELEC RE2 P2.5 C78, 80

23557-0660 CAP 2200U 16V ELEC RE2 P5 C75

23557-0664 CAP 1000U 35V ELEC RE2 P5 C72, 73

23557-0673 CAP 22U 35V ELEC RE2 P2 C7, 202, 231

23557-9122 CAP 4700U 16V ELEC RE2 P7.5 C74

23620-0242 CAP 22NJ 100V P/E P5 C227

23620-0246 CAP 100NK 63V P/E P5 C228

23620-0249 CAP 330NK 63V P/E P5 C64, 65

23620-0252 CAP 2N2K 63V P/E P5 C226

25021-0901 DIO 1N4148 B/R D1-3, 5-9, 200-207, 213, 214

25061-0200 LED - T1 ROUND (3mm) - RED LED1, LD200

25115-0907 DIO 1N4002 B/R D10-13

25130-9201 DIO ZEN 6V2 W5 D208

25131-0224 DIO ZEN 18V 1W3 D14, 15

25131-0227 DIO ZEN 6V8 5W D16-18

25174-0224 DIO SM VARICAP BB148 D209-212

25211-9302 RECTIFIER BRIDGE W02G BR1

25334-0011 TRAN PNP TIP30 Q22

25336-5590 TRAN PNP BC559C Q1, 3, 6-13

25377-5490 TRAN NPN BC549C Q2, 4, 5, 14, 15, 20, 21, 200-205

27103-0041 IC NE527N IC201

27103-1020 IC SM AD8561AR IC205

27106-0517 IC NE5532N IC218

24

PCB ASSY – MAIN (44912-0720) continued/...

Part Number Description Position

27106-0633 IC EL2099CT IC220

27106-1110 IC SM LM358M DUAL OP AMP IC16, 200

27106-1160 IC SM LM324M OP AMP IC209

27106-1170 IC SM AD8055AR OP AMP IC219

27106-1180 IC SM AD8056AR OP AMP IC25, 216

27106-1210 IC SM LMC662CM IC29, 115

27107-0071 IC SM TL071 BIFET OP AMP IC207

27151-1010 IC AD835AN IC215

27153-1050 IC SM LTC1257CS8 IC27

27153-1060 IC SM TLC5620CD DAC IC208

27153-1070 IC SM HI5735KCB DAC IC210

27158-0020 IC SM MC145170D IC206

27158-0030 IC SM MC12148D IC203

27160-0011 IC V/REG 78L05 TO92 IC108, 204, 226

27160-0013 IC V/REG 7815 TO220 IC30

27160-0020 IC V/REG 7915 T0220 IC31

27160-0210 IC V/REG LM337 TO220 IC33

27160-0460 IC V/REG L4941BV IC32, 34

27227-0510 IC SM 4051 IC28

27227-0940 IC SM 4094 IC18, 19

27236-0520 IC SM 74HC4052 IC211, 212, 217

27236-0530 IC SM 74HC4053 IC213, 214

27238-0000 IC SM 74HCT00 IC202

27238-0140 IC SM 74HCT14 IC11, 21

27239-0000 IC SM 74HC00 IC22

27239-0320 IC SM 74HC32 IC14, 15, 20

27239-2400 IC SM 74HC240 IC23

27239-3730 IC SM 74HC373 IC12, 13

27253-0020 IC SM 64180 IC3

27253-0050 IC SM 14C88 IC1

27253-0060 IC SM 14C89 IC2

27400-0140 IC 27C4001 512Kx8 EPROM IC4

27403-0010 IC SM 93C46 1K(64x16) EEPR IC17

27410-0460 IC SM 32KX8 RAM 15ns IC222-225

27412-0080 IC SM XCS10-4TQ144C IC221

27412-0090 IC SM XCS05-3VQ100C IC10

27413-0430 IC SM 128Kx8 RAM 70ns IC5-9

25

PCB ASSY – MAIN (44912-0720) continued/...

Part Number Description Position

28151-0010 BUZZER BUZZ

28502-0020 RESONATOR CERAMIC 12MHZ XTL1

28515-0070 OSC MODULE 10MHz VCXO IC105

31331-9030 SCREEN PCB MOUNT S205, 206

35555-3210 PCB - MAIN

FRONT PANEL ASSY

Part Number Description Position

20030-0263 WASHER M3 ZPST BEZEL

20030-9201 WASHER 6BA x 1/32in. FIBRE LCD FIXING

20030-9202 WASHER 6BA x 1/16in. FIBRE LCD FIXING

20038-9501 WASHER M3 SPRING KEYBOARD PCB/FRONT PANEL

20065-0090 SCREW K22 X 5 PT LN1442 PNHDZ BEZEL FIXING

20210-0104 NUT M2.5 ZPST LCD FIXING

20234-0027 SCREW M3 X 6 PNHDPZ ZPST KEYBOARD PCB/FRONT PANEL, BEZEL

20234-0040 SCREW M2.5 X 12MML PNHDPZ ZPST LCD FIXING

20612-0011 WASHER FIBRE M3 KEYBOARD PCB/FRONT PANEL

20620-0010 CLIP - ENCODER KNOB

22219-0090 SWITCH ROCKER DPST GREY

22573-0056 HEADER 16WAY STR SIL STD FOR DISPLAY

22575-0202 SKT 2W .156 20AWG (YELLOW) IDT MAIN PCB PJ200A & PJ200B, PJ7

22575-0204 SKT 4W .156 20AWG (YELLOW) IDT INTERFACE 1 PJ6

22588-0004 BNC SKT BKHD 50R STANDARD

26100-0160 LCD 20 X 4 BACK LIT

31711-0180 BEZEL

33331-7210 FRONT PANEL

33331-7290 OVERLAY FRONT PANEL

37113-2030 KEYCAP 8X3MM LIGHT GREY

37151-0430 KNOB ENCODER LIGHT GREY

43171-1400 CONN ASSY 2 WAY 285MM PJ12, 200 (MAIN)

43171-1401 CONN ASSY 2 WAY 195MM PJ13 (MAIN)

43171-2210 CONN ASSY CRIMPED

26

REAR PANEL ASSY

Part Number Description Position

20037-0401 SOLDER TAG SHAKEPROOF - 4BA EARTH

20038-9502 WASHER M4 SPRING EARTH

20063-0010 SCREW NO6 X 3/8 NIB HDPZ ST/AB TRANSFORMER

20210-0102 NUT M4 ZPST EARTH

20213-0040 CAPTIVE NUT SPIRE NO.6

20223-9001 SCREW M3 X 8 RAISED CKHDPZ MAINS INLET

20236-0010 SCREW M4 X 12 TAMPERPROOF EARTH

22115-0340 TRANSFORMER

22520-0170 FILTER - IEC INLET + FUSE - 1A

20037-0401 SOLDER TAG SHAKEPROOF - 4BA EARTH

20038-9502 WASHER M4 SPRING EARTH

20063-0010 SCREW No 6 x 3/8 NIB HDPZ ST/AB TRANSFORMER

22588-0004 BNC SKT BKHD 50R STANDARD

33331-7430 REAR PANEL PRINTED

43171-1401 CONN ASSY 2 WAY 195MM PJ1, 3, 11 MAIN

CASING AND OTHER ITEMS

Part Number Description Position

10144-0007

20030-0266 WASHER M4 ZPST RUBBER FEET

20037-0301 WASHER M3 SHK/PROOF I/T ZPST CHASSIS/F. PANEL

20038-9501 WASHER M3 SPRING CHASSIS/SPACERS, PCB/SPACERS,

20062-0700 SCREW NO 6 X 3/8 RFLNGPZ ST/AB CHASSIS/REAR PANEL

20063-0010 SCREW NO6 X 3/8 NIB HDPZ ST/AB CASE UPPER

20210-0101 NUT M3 ZPST FRONT PANEL

20213-0040 CAPTIVE NUT SPIRE NO.6 CHASSIS

20234-0012 SCREW M3 X 8 PNHDPZ ZPST CHASSIS

20234-0027 SCREW M3 X 6 PNHDPZ ZPST CHASSIS/SPACERS, PCB/SPACERS

20234-0029 SCREW M4 X 12 PNHDPZ ZPST FEET

CABLE COAX 50Ω 2.6MM RG316/U

BNC TO PCB MAIN (PJ202)

FRONT PANEL

20612-0011 WASHER FIBRE M3 PCB/SPACERS

20661-0219 SPACER HEX M3 x 15 NPBR

20662-0201 BRACKET PLAS FOOT 3786-7001

20662-0520 FOOT PVC PV2629 BLACK

22315-0232 FUSE 250MA TL HRC S/F 230V VERSIONS

22315-0233 FUSE 500MA TL HRC S/F 115V VERSIONS

27

CASING AND OTHER ITEMS continued/...

Part Number Description Position

22491-0120 MAINS LD 2M ST IEC/UK PLUG 5A UK VERSIONS

22491-0270 MAINS LD 2M ST IEC/EURO PLUG EURO VERSIONS

22491-0040 MAINS LD 2M ST IEC/USA PL USA VERSIONS

22469-0203 SOLDER TERMINAL PIN (18-0223K) DISPLAY CABLE

22575-0202 SKT2W .156 20AWG (YELLOW )IDT PJ3, 7,11,12,200 ON MAIN

22575-0204 SKT4W .156 20AWG (YELLOW) IDT PJ13 ON MAIN

22575-0206 SKT6W .156 20AWG (YELLOW) IDT PJ8 ON MAIN

33171-0130 SPRING FOOT

33537-0900 CASE UPPER

33537-0910 CASE LOWER

43171-1430 CONN ASSY GPIB/MAIN 20W

43171-2250 CONN ASSY DIS/MAIN 34W

48584-0221 CONN ASSY RS232/PC SCRND 2M

28

Main Pcb

Component Layouts

29

Keyboard Pcb

GPIB Pcb

30

Circuit Diagrams

31

Gpib Interface Pcb

Keyboard Pcb

Main Pcb Sheet 1 of 4
MPU and Interfaces

Main Pcb Sheet 2 of 4
Analogue Section

Main Pcb Sheet 3 of 4
Waveform FPGA and Memory

Main Pcb Sheet 4 of 4
Power Supplies