Acterna SPM-32A User manual

SPM-32A ... SPM-36A
Selective Level Meters
Operating Manual
BN 4033/00.82

SPM-32A ... SPM-36A
Selective Level Meters
Operating Manual
SPM-32A, BN 4033/11:
50 Hz to 620 kHz, Series O ...
SPM-33A, BN 4033/01:
50 Hz to 2 MHz, Series O ...
SPM-34A, BN 4033/20:
50 Hz to 2 MHz, Series O ...
SPM-35A, BN 4033/30:
50 Hz to 2 MHz, Series Z ...
SPM-36A, BN 4033/36:
50 Hz to 3.5 MHz, Series AG ...

Please direct all enquiries to your
local Acterna sales company. The
addresses are given at the end of this
handbook.
Copyrights
This product or parts of it are based upon Recom-
mendations and/or Standards of the Standardiza-
tion Sector of the International Telecommunication
Union - ITU-T and/or of the European Telecommu-
nications Standards Institute - ETSI. These Recom-
mendations and Standards are subject to
copyrights of these organizations. Without written
permission of the ITU-T and/or ETSI it is not permit-
ted to copy ITU-T Recommendations or ETSI stand-
ards or parts thereof and/or make them available to
third parties.
Acterna Plymouth Ltd.
Eurotech House
Burrington Way
Plymouth PL5 3LZ
Order no.: BN 4033/00.82
Edition: 02/ 02.08.02 O ..., Z ..., AG ...
Note: Specifications, terms and conditions
are subject to change without prior notice.
© Copyright 2002 Acterna, LLC.
All rights reserved.
Acterna, The Keepers of Communications,
and its logo are trademarks of Acterna, LLC.
All other trademarks and registered trade-
marks are the property of their respective
owners.
Printed in the United Kingdom

Contents
1 FOREWORD. . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.1 About these instruments . . . . . . . . . 1-1
1.2 About this handbook . . . . . . . . . . . . 1-3
2 Safety information . . . . . . . . . . . . . . . . . . . 2-1
3 GENERAL INFORMATION
FOR THE USER 3-1
3.1 Display contrast . . . . . . . . . . . . . . . 3-1
3.2 Power supplies . . . . . . . . . . . . . . . . 3-2
3.2.1 AC line power . . . . . . . . . . . . . . . . . 3-2
3.2.2 Battery power . . . . . . . . . . . . . . . . . 3-3
3.2.3 Important note for all instruments . . 3-9
3.3 Switching on the instrument . . . . . 3-10
3.4 Default settings (reset) . . . . . . . . . 3-13
3.5 Electromagnetic compatibility . . . . 3-14
3.6 Cleaning the instrument . . . . . . . . 3-14
4 OPERATION. . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.1 Overview. . . . . . . . . . . . . . . . . . . . . 4-1
4.1.1 Connectors and keys . . . . . . . . . . . 4-1

4.1.2 Display . . . . . . . . . . . . . . . . . . . . . . 4-11
4.2 Operation and features . . . . . . . . . 4-15
4.2.1 Operating modes . . . . . . . . . . . . . . 4-15
4.2.1.1 Selective level measurements . . . . 4-16
4.2.1.2 Wideband measurements . . . . . . . 4-18
4.2.1.3 SSB demodulation (DEMOD) . . . . 4-20
4.2.2 Inputs, input impedances (Z/W). . . 4-22
4.2.3 Receive frequency (FREQ) . . . . . . 4-26
4.2.3.1 Frequency entry (TUNE: keypad or
steps) . . . . . . . . . . . . . . . . . . . . . . . 4-27
4.2.3.2 Frequency entry (STEP: keypad,
adjustable step width) . . . . . . . . . . 4-29
4.2.3.3 SEARCH . . . . . . . . . . . . . . . . . . . . 4-31
4.2.3.4 AFC . . . . . . . . . . . . . . . . . . . . . . . . 4-37
4.2.4 Bandwidths . . . . . . . . . . . . . . . . . . 4-39
4.2.4.1 Setting the bandwidth . . . . . . . . . . 4-43
4.2.5 Level mode . . . . . . . . . . . . . . . . . . 4-46
4.2.5.1 Absolute level (ABS) . . . . . . . . . . . 4-47
4.2.5.2 Level difference (ABS-REF),
reference level (REF). . . . . . . . . . . 4-50
4.2.5.3 Levels in dBm0, relative levels
(REL) . . . . . . . . . . . . . . . . . . . . . . . 4-54
4.2.6 Bargraph, AVRG, MAX. HOLD . . . 4-56
4.2.6.1 Bargraph . . . . . . . . . . . . . . . . . . . . 4-56

4.2.6.2 Display averaging (AVRG) . . . . . . 4-58
4.2.6.3 MAX.HOLD . . . . . . . . . . . . . . . . . . 4-59
4.2.7 Storing setups (MEMORY) . . . . . . 4-60
4.2.7.1 Addresses. . . . . . . . . . . . . . . . . . . 4-60
4.2.7.2 Storing a setup (STO). . . . . . . . . . 4-62
4.2.7.3 Recall setup (RCL) . . . . . . . . . . . . 4-64
4.2.7.4 DISPLAY. . . . . . . . . . . . . . . . . . . . 4-67
4.2.8 Avoiding errors due to large
common-mode voltages . . . . . . . . 4-68
5 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . 5-1
5.1 Inputs . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.2 Frequency. . . . . . . . . . . . . . . . . . . . 5-2
5.3 Level measurements . . . . . . . . . . . 5-5
5.3.1 Measured quantities . . . . . . . . . . . . 5-5
5.3.2 Level display . . . . . . . . . . . . . . . . . . 5-5
5.3.3 Display range . . . . . . . . . . . . . . . . . 5-6
5.4 Error limits of the level display . . . . 5-7
5.4.1 Intrinsic error and variation with
level . . . . . . . . . . . . . . . . . . . . . . . . 5-7
5.4.2 Variation of level display with
frequency . . . . . . . . . . . . . . . . . . . . 5-9
5.4.3 Total error . . . . . . . . . . . . . . . . . . . 5-10

5.5 Selectivity, bandwidth selectable . . 5-12
5.6 Harmonic ratio ak2, ak3. . . . . . . . . 5-14
5.7 Demodulator . . . . . . . . . . . . . . . . . 5-14
5.8 Memory . . . . . . . . . . . . . . . . . . . . . 5-14
5.9 General specifications . . . . . . . . . . 5-15
5.9.1 Power supply . . . . . . . . . . . . . . . . . 5-15
5.9.2 Ambient conditions. . . . . . . . . . . . . 5-15
5.9.3 Electromagnetic compatibility . . . . 5-16
5.9.4 Safety information . . . . . . . . . . . . . 5-16
5.10 Ordering information . . . . . . . . . . . 5-17
Index

SPM-32A ... SPM-36A 1.1 About these instruments
1-1
1FOREWORD
1.1 About these instruments
The SPM-32A, 33A, 36A series of Selective Level Meters
are designed as in-service test sets for CF communications
systems using up to 120, 300 or 600 channels respectively.
The SPM-34A Selective Level Meter is particularly suitable
for making level measurements on instruments and
equipment used in telex and telecontrol systems as well as
in telephony. Four bandwidths are specially tailored for
making in-service measurements on ITU-T FM VFT
channels with transmission rates of 50, 100, 200 and 600
Baud.
The SPM-35A Selective Level Meter is suitable for analyzing
a mixture of frequencies and for measurements on ARI and
RDS systems, as well as telecontrol and ITU-T FM VFT
systems operating at 50, 100 and 200 Baud. The minimum
bandwidth of 5 Hz is useful for measuring discrete signals
starting at 50 Hz (e.g. subaudio tones) and composite
signals, such as spectral components of analog (ARI) and
digital (RDS) traffic radio signals in the multiplex baseband of
UHF transmitters. These signals are located close to the 57
kHz auxiliary carrier. The 25 Hz bandwidth is suitable for
easurement of pilots and residual carriers. Special
bandwidths for keyed signals make the instrument optimal
for in-service measurements on FM-VFt and remote control
systems.
Tabelle1-0
Bild 1-0

1.1 About these instruments SPM-32A ... SPM-36A
1-2
When combined with the PS-33A Level Generator (2 MHz),
each of the instruments forms a complete test setup for
measuring level , gain and attenuation.
The built-in synthesizer and 1 Hz frequency resolution allow
accurate, stable frequency settings across the entire range.
This greatly simplifies tuning to pilots using a narrow
resolution bandwidth. The instrument key with user-
selectable stepsize is useful for measurements on evenly
spaced channels. Fixed frequencies such as pilots can be
stored in memory to speed up routine tests.
The digital display indicates absolute and relative level with
0.01 dB resolution, allowing measurement of very small level
differences. The fast bargraph is very useful for alignment
work.
A demodulator with an integral loudspeaker can be used to
monitor the input signal.
The current result is also stored when the setup is stored; the
memory can be used as an electronic notebook up to 100
results.
The display provides a quick overview of all functions
currently in use. Other functions such as frequency scan,
AFC, demodulation, setups and storage of fixed frequencies
contribute to fast and error-free test procedures.
The instrument is ideal for field applications (e.g. in service
testing, maintenance) due to its simple operation, wide
temperature range, rugged design and flexible powering
options (a.c. line or batteries). Using the BAZ-33 Battery
Pack (accessory), the level meters can be operated for 8
hours from battery power.

SPM-32A ... SPM-36A 1.2 About this handbook
1-3
1.2 About this handbook
Textual conventions
All instruments in the SPM-33 family are described in this
handbook. Where the instruments differ, this is indicated by
an appropriate fotnote or by the instrument name in the
subheading.
Keypad operation
To use the functions in yellow, press the yellow key with the
asterisks beforehand.
Example:
"MAX:HOLD": Display of the highest
RMS value which occurs during the
observation time interval (for use with
fluctuating signals).
Graphic conventions
The display illustrations have been generated using a
computer and all essential features of the display are shown.
The part of the display referred to in the text is, however,
shown in bold characters for the sake of clarity. The actual
display does not, of course, make these distinctions.
DEMOD
*
MAX.HOLD

1.2 About this handbook SPM-32A ... SPM-36A
1-4
Example: in this figure "BATTERY?" is written in bold script
as this aspect of the instrument is being discussed.
74
150

SPM-32A ... SPM-36A 2 Safety information
2-1
2 Safety information
Before connecting up
The instruments left the factory in perfect condition. To
ensure correct and safe operation, please read the following
information before using the equipment.
Correct usage
The instruments may only be used under the conditions and
for the purposes for which they are intended. In this regard
please note the information contained in Section 1
(Foreword) and Section 5 (Specifications).
Safety information for operation in a
telephone network
This device is designed for use on telephone lines. It com-
plies with safety norm EN 41003. In this context, the LNT-2
charger unit is required for a.c. line operation.
This assures that electrical circuits connected to the tele-
phone network are not exposed.
Tabelle2-0
Bild 2-0
Pay attention to max. input voltages
(see section 4.2.2).

2 Safety information SPM-32A ... SPM-36A
2-2
Safety information:
LNT-2 AC Adapter/Charger Unit
AC line voltage Before use, make sure that the
operating voltage of the LNT-2 and the
local AC power supply voltage are the
same.
Fuse The excess-temperature fuse built into
the device does not depend on the a.c.
line voltage setting. It is not necessary to
check or exchange this a.c. line fuse.
Safety class The LNT-2 is a safety class II equipment
to IEC 1010-1 (VDE 0411 and IEC Publ.
348).
Faults If it is thought that the instrument is no
or damage longer safe to operate, the LNT-2 should
be disabled and secured against
unintentional operation.
Repairs Repairs must be correctly made. In par-
ticular, the construction characteristics
of the LNT-2 must not be altered in any
way which may be detrimental to the
safety of the equipment. This applies
particularly to creepage and air paths.
Before opening the LNT-2, disconnect it
from all power sources.

SPM-32A ... SPM-36A 2 Safety information
2-3
Spare parts Only original spare parts should be
used. Spare parts from other sources
may be used only if their use does not
adversely affect the safety of the LNT-2.
Temperature The LNT-2 is intended for use indoors
and can be operated at temperatures
between 0 and + 50 °C.
Ventilation When the LNT-2 is in use it should be
placed such as to ensure adequate
ventilation.
Condensation The LNT-2 must not be operated if
condensation has formed on it. If
condensation is unavoidable, as when
the cold LNT-2 is brought into a warm
room, it must be allowed to dry out
before being switched on.

2 Safety information SPM-32A ... SPM-36A
2-4
Notes:

SPM-32A ... SPM-36A 3.1 Display contrast
3-1
3 GENERAL INFORMATION
FOR THE USER
3.1 Display contrast
Similar to modern pocket calculators, these instruments
have an LCD display. The display contrast depends on:
– the light incident on the display
– the viewing angle
Fig. 3-1 Normal viewing angle. The contrast can be adjusted by
means of the contrast control (in hole in side of set).
If you are viewing the instrument at a different angle, adjust
the contrast accordingly.
Tabelle3-0
Bild 3-0

3.2 Power supplies SPM-32A ... SPM-36A
3-2
You will find the contrast control in the hole in the lefthand
side of the set. You can adjust the control with a thin
screwdriver. Set the contrast so that
– the lettering is clear and
– the background grid can scarcely be seen
3.2 Power supplies
The instruments can use one of four types of power supply:
– an a.c. adapter/charger
– two 9 V dry batteries
– two rechargeable batteries (NiMH)
– the BAZ-33 battery pack. Note the operating instructions
for the BAZ-33 battery pack.
3.2.1 AC line power
The LNT-2 AC Adapter/Charger Unit, BN 2071/90.021is
designated for powering the instrument from the a.c.line.
•Plug the charger cable jack into the socket on the right-
hand side of the instrument.
•If batteries or NiMHs are fitted, plugging and unplugging
the charger cable will not interrupt the power supply to the
unit. Power will always be drawn from the a.c. adapter/
charger when it is plugged into the instrument.
1 see section 2: Safety information

SPM-32A ... SPM-36A 3.2 Power supplies
3-3
•Even if you only intend to operate the instrument from the
a.c. line power supply, batteries or NiMHs should be fitted
to prevent loss of stored data in the event of a power
supply failure.
If no batteries are fitted, or if the batteries are flat, the
"BATTERY?" warning message will be displayed even if the
instrument is connected to the a.c. adapter/charger (see
section “Low batteries“).
•The auto-off circuit which normally operates after 15
minutes when batteries are used is disabled when
theinstrument is operated from an a.c. adapter/charger.
(see section 3.3 on page 3-10).
3.2.2 Battery power
Two 9 V dry batteries or two rechargeable batteries are
required. The following are suitable:
– Manganese/alkaline batteries (IEC 6LF22 or 6LR61);
these give an operating time of about 8 hours, or
– Rechargeable NiMH batteries (same size as 6LF22);
these give an operating time of about 2 hours.
Acterna supply suitable rechargeable batteries, see
accessories (Specifications).
Fig. 3-2 Terminals of 9 V rechargeable battery with charger contact

3.2 Power supplies SPM-32A ... SPM-36A
3-4
Low batteries
If the batteries are low,
– "BATTERY?" is displayed, and
– the instrument is switched off automatically after a few
minutes.
The built-in lithium battery ensures that the memory contents
are retained.
Fig. 3-3 Battery low warning
•The battery low warning "BATTERY?" is temporarily
cleared when you press a function key. It will however
reappear after about a minute because the battery
voltage is measured at one-minute intervals.
•The warning will also be displayed when the instrument is
powered by the AC adapter and there are no batteries in
the set.
74
150