Rohde & Schwarz CMS 33 User manual

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Test and Measurement Division

Operating Manual

RADIOCOMMUNICATION SERVICE MONITOR CMS 33 840.0009.34

Printed in the Federal Republic of Germany

1078.1930.12-01-

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Operation of Basic Instrument and Options	1
Operation of Autorun/Printer Control	2
Operation of VOR / ILS-Generator	3
Operation of Remote Control Box	4

Index

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Test and Measurement Division

Basic Instrument and Options

Printed in the Federal Republic of Germany

840.0009.33

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Contents

Page

1	Technical Information
2	Operation	2.1
2.1	Explanation of Front and Rear Views	2.1
2.1.1	Front Panel	2.1
2.1.2	Rear Panel	2.4
2.1.3	Remote Control Box	2.5
2.1.4	Batterie pack	2.5
2.2	Preparation for Use	2.6
2.2.1	AC Power Mode	2.6
2.2.2	Battery Mode	2.6
2.2.3	Operating Instructions for CMS Z-42 Battery Pack 1065.5803.02	2.6
22	Operation	2.9
2.5	Power Up Status	29
2.3.1 2.3.2	Power-Up Status	2.9
2.3.2.1 2.3.2.2 2.3.2.2.1 2.3.2.2.2 2.3.2.2.3 2.3.2.3 2.3.2.3 2.3.2.4	Softkeys Hardkeys Function-based Hardkeys Mode-related Hardkeys Independent Hardkeys VAR Spinwheel Display	2.9 2.9 2.13 2.13 2.14 2.14
2.3.3	Menu Structure	2.15
2.3.4	Error Reaction	2.16
2.3.5	Connection of Device under Test (DUT)	2.16
2.3.6	Selection Menu	2.16
2.4	Transmitter Test (TX-Test)	2.17
2.4.1	RF Measurement	2.17
2.4.2	Power Measurement	2.20
2.4.3	Demodulation	2.22
2.4.4	AF Measurement	2.24
2.4.5	Filter Selection	2.26
2.4.6	Distortion and S/N Measurements	2.28
2.4.7	Input Switchover	2.30
2.4.8	Lock	2.30
2.4.9	Modulation Generators	2.30
2.4.10	Oscilloscope / DC Measurement	2.31

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2.5 Receiver Test (RX-Test) 2.33 251 RF Setting .................................... 252 RF Level Setting .................................... 253 AF Level Measurement 2.36 254 Code, Count .................................... 255 Filter Selection 240 256 SINAD and Distortion Measurements .................................... 257 S/N Measurement .................................... 258 Lock .................................... Modulation Generators ..... 2.43 2.5.9 Oscilloscope / DC Measurement .................................... 2.6 SSB-Transmitter Test (TX-SSB) 2 46 2.6.1 RF Count Measurement ..... 2.46 2.6.2 Power Measurement 248 2.6.3 MODE Function .................................... 2.6.4 AF Measurement 2 48 2.6.5 Filter Selection 2.49 2.7 SSB-Transmitter Test (RX-SSB) ................................... RF Setting 2 5 2 272 Mode Function 2.52 273 AF Level Measurement .................................... 274 AF Count Measurement 2.53 275 Filter Selection 2.53 276 SINAD and Distortion Measurements 2.53 277 Code 2.53 278 Lock 2.53 279 Modulation Generators .................................... 2710 Oscilloscope / DC Measurement 2.54 RF Spectrum Analyzer .................................... 2.8 Functions of the Main Menu .................................... 2.8.1 Settling the Reference Level ................................... 2.8.2 Freeze Mode .................................... 283 2.8.4 Spectrum Analyzer in IEC-bus Mode ....................................

E-1

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2.9 Definition Menu for Tones

2.9.1 Selection of Standard	2.58
2.9.2 Tone Duration	2.59
2.9.3 Pause	2.59
2.9.4 Frequency Definition	2.59
2.9.5 Coupling of Standards	2.60
2.9.6 Decoding Time	2.60

2.10 Definition Menu for Special Functions	2.61
2.10.1 Search Routines	2.61
2.10.2 Display Illumination	2.62
2.10.3 Relay and TTL Interface	2.62
2.10.4 ZOOM
2.10.5 LO Frequency LO/HIGH	2.65
2.10.6 IEC/IEE Bus
2.10.7 Serial Interface
2.10.8 Selection of Printer
2.10.9 AF Voltmeter (Reference Resistance)	2.65
2.10.10 External Reference Frequency	2.65
2.10.11 Acoustic Acknowledgement
2.10.12 Warnings
2.10.13 Master Reset

2.11 Remote Control	2.66
2.11.1 Setting the Device Address
2.11.2 Local/Remote Switchover	2.67
2.11.3 Interface Messages	2.67
2.11.3.1 Universal Commands
2 11 A Device Messages	2.69
2.11.4.1 Commands Received by the CMS in Listene	er Mode
(Controller to Device Messages)	2.69
(Device to Controller Messages)
(
2.11.4.3 Device-independent Commands
2.11.4.3 Device-independent Commands (Common Commands) 2.11.4.4 Device-specific Commands
2.11.4.3 Device-independent Commands (Common Commands) 2.11.4.4 Device-specific Commands 2.11.5 Service Request and Status Registers	2.77
2.11.4.3Device-independent Commands (Common Commands)2.11.4.4Device-specific Commands2.11.5Service Request and Status Registers2.11.6Resetting of Device Functions	2.77 2.90 2.94
2.11.4.3Device-independent Commands (Common Commands)2.11.4.4Device-specific Commands2.11.5Service Request and Status Registers2.11.6Resetting of Device Functions2.11.7Command Processing Sequence and Synch	2.77 2.90 2.94 ronization 2.95

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2.12	IMPED Ω Menu	2.97

2.13	Serial Interface	2.98
2.13.1	Using the Interface	2.98
2.13.2	Interface Configuration	2.101

2.14	Self-Test	2.105
2.14.1	Calibration of Peak Meter	2.105
2.14.2	Calibration of RMS Meter	2.105
2.14.3	Calibration of Distortion Meter	2.105
2.14.4	Power Calibration	2.105
2.14.5	Calibration of Modulation Generator	2.105
2.14.6	Adjustment of Modulation Generator Filter	2.106
2.14.7	Synthesizer Calibration	2.106
2.14.8	Battery Check	2.106
2.14.9	Cyclic Calibration	2.106
2.14.10	Limits of Calibration Values	2.107
2.14.11	Error Messages	2.108

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3 Performance Test

3.1	Required Measuring Instruments and Accessories	3.1
3.2	Testing the Rated Specifications	3.2
3.2.1	General	3.2
3.2.2	Reference Frequency	3.2
3.2.3	Frequency Setting and Harmonics and Non-harmonics Ratio	3.3
3.2.4	Spurious FM and AM	3.3
3.2.5	RF Frequency Response of the Output Level	3.3
3.2.6	Fine Level Setting	3.3
3.2.7	RF Attenuator	3.3
3.2.8 3.2.8.1 3.2.8.2	FM Modulation Internal FM Modulation External FM Modulation	3.4 3.4 3.4
3.2.9	AM Modulation	3.5
3.2.9.1 3.2.9.2	Internal AM Modulation	3.5 3.5
3.2.10	Modulation Generator	3.5
3.2.11	AF Voltmeter	3.6
3.2.12	Lowpass and Highpass Filter	3.6
3.2.13	Resonance Filter	3.7
3.2.14	Psophometric Filter	3.7
3.2.15	Distortion Meter	3.7
3.2.16	AF Counter	3.8
3.2.17	RF Counter	3.8
3.2.18	Power Meter	3.8
3.2.19	Automatic Switchover with Incoming Power	3.8
3.2.20	Frequency Deviation Meter	3.9
3.2.21	Phase Deviation Meter	3.9
3.2.22	AM Meter	3.9
3.2.23	Oscilloscope and Loudspeaker	3.10
3.2.24	DTMF Decoder	3.10
3.2.25	RF Spectrum Monitor	3.10
3.3	Performance Test Report	3.11
3.4	Maintenance	3.21
3.4.1	Electrical Maintenance	3.21
3.4.2	Mechanical Maintenance	3.21
3.5	Storage	3.21

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Radiocommunication Service Monitor CMS 33

400 kHz to 1000 MHz

Navigation:
VOR(VHF Omnidirectional Radiorange)ILS(Instrument Landing System)MB(Marker Beacon)ADF(Automatic Directional Finder)Auto ILS(Automatic ILS = autopilot)HOMING(Automatic ILS = autopilot)
Communication: HF (SSB Transceiver) VHF/UHF (AM/FM Transceiver) SELCAL (Selective Call)
Intercom: Sidetone test Crew station box test

1007.8532 E-2

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CMS 33 ID 0840.0009.34

Complete test set for testing the communication and navigation instruments in aircraft both with a direct connection to the antenna input of the transceiver and offair using a test antenna
Comprehensive measuring equipment including VSWR, spectrum monitor and transient recorder opens all kinds of measurement applications.
Off-air tests for fast and comfortable testing of the navigation instruments without connecting and exchanging hard-to-get-at antenna inputs
The only radio tester with an integrated VOR/ILS generator which has already been established on the market and welltested by national aviation control authorities and armed forces.
Ease of operation thanks to a clear operational concept and a large 9"-LCD display. Interactions with operators are reduced to a minimum by means of test routines consisting of clear, user-specific instructions. This means that even complex measurement tasks in large service organisations can be standardized and reproduced.
Prepared automatic test routines for fast verification of entire NAV/COM/INTERCOM equipment
Automatic or manual impedance matching to INTERCOM networks ensures no operator error and a complete one box solution.
Minimal weight and small size for portable and stationary use; can be comfortably used even in very confined places such as a cockpit due to an optional small external operating panel.
Minimal power consumption ensures long battery service life for on-site work
Modular, future-oriented concept with selftest and automatic self-adjustment to permit long calibration intervals and low operating costs
Simple and safe logistics for programs and their modifications

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CMS 33

On the basis of more than 20 years of experience in the development and manufacture of compact radio testers, the 'Radiocommunication Service Monitor CMS33' is the consequent development of the successful CMS family for the demanding applications in the avionics field. A universal, most modern concept, minimal weight, small size and most simple operation render the CMS33 equally ideal for mobile use on-site as a ramp tester and, thanks to its outstanding data and flexibility, as a bench tester for repair and maintenance in laboratories.

The CMS33 has been developed to match the special requirements in the measurement of communication and navigation instruments. Short test times, low operating costs, simple operation and the CMS33 being one-man portable were highly important design goals. Portability, splash protection, universal power supply, off-air measurements using a test antenna and a remote operating feature for the direct use in confined places additionally improve usability. All further accessories such as VSWR inser-

tion unit, cable, program card and user guide can be accommodated ready to hand in the transit case.

The CMS33 tests AM, FM and SSB transceivers in the HF, VHF and UHF range including the necessary selective-call methods (SELCAL) and also permits the audio-analysis of the INTERCOM network. This satisfies all test requirements in the field of aircraft communication. For the navigational test, the CMS33 generates exact signals for a precise reading of the navigation instruments. All necessary signal sources to test VOR, ILS, Marker Beacon, Autopilot, Homing and ADF are available.

In automatic operation, a pass/fail message indicates conformity/non-conformity with settled tolerances in order to ensure a fast exchange of a defect unit. Program cards store the exact measurement results which, when printed out, serve as an important source of information for repair. Ultimate precision makes the CMS33 the ideal measurement equipment also in repair workshops.

Measurements

The CMS33 offers the complete measurement program of a modern radio test set (cf. data sheet CMS family as well). Thus the CMS33 replaces various measurement instruments in the workshop. Further, it provides additional measurement equipment for the efficient and effective operation at transceivers and navigational receivers in aircrafts.

General Tests and Measurements

Signal sources

RF synthesizer from 0.4 to 1000 MHz, resolution 10 Hz, with AM, FM, φM and multitone modulation capabilities
Two independent modulation generators, 20 Hz to 20 kHz each, resolution 0.1 Hz
SELCAL coder and various other selective call standards
VOR/ILS signal generator

Measuring facilities

RF frequency counter, RF frequency-offset counter
RF power meter from 5 mW to 125 W
Selective RF power meter down to -100 dBm

Modulation meter for AM, FM and φM; weighting: +PK, -PK, PK HOLD, ±PK/2, RMS, RMS $\sqrt{2}$
AF voltmeter with peak and true RMS weighting
SINAD and Distortion meter with variable test frequency
S/N meter
AF frequency counter
Selective-call decoder for all standards
Oscilloscope
Transient recorder (optional)

Filters

CCITT filter for weighting to relevant standards
Continuously tunable bandpass filter from 50 Hz to 5 kHz with high skirt selectivity for selective modulation and AF measurement
Continuously tunable notch filter from 100 Hz to 5 kHz for signal suppression
Highpass and lowpass filters for band limiting and measurement of subaudio tones

Other facilities

Second RF input of high sensitivity for off-air measurements
Internal memory for storing complete instrument setups

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CMS 33

ID 0840.0009.34

Receiver measurements, supported by automatic test routines for sensitivity, bandwidth, quieting and squelch, enable fast and thorough service work.

Thanks to simultaneous display of all parameters, the transmit signal quality can be immediately monitored and additionally evaluated. The optional transient recorder allows for measurement of power and frequency settling characteristics of transmitters - as shown in the attached menu - as well as for recording of power bursts.

The built-in signal generator for VOR, ILS and MB provides fast and convenient test of nav aids. Free defineable phase increments in VOR testing allow together with the autorun function to check the smooth movement of the steering indicators.

Fine variation of DDM value in steps of 0.001 DDM for ILS and of phase in steps of 0.01° for VOR ensure accurate adjustment of onboard indicators.

An AF oscillogram can be displayed in all operating modes and allows for instance simultaneous display of the bearing signal demodulated by the device under test.

A menu is also available for signal generation of marker beacons.

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CMS 33

ID 0840.0009.34

CMS33 Specific Measurement - Added Value in the Avionic Fields

The CMS 33 has been developed in close cooperation with many different users. As a result, three main operation modes are available for different applications in the avionics field: on one hand there is often only inconvenient access to the various antenna inputs of an aircraft. That's why the CMS33 is designed and ready-to-use for off-air measurements. On the other hand tests have to be performed in confined places (e.g. in the cockpit of airfighters). The CMS33 responds by being remote controllable by a small and handy external control panel. Finally auto-run programs facilitate complete checks of installations in a few minutes.

Impedance Matching

AF matching to the different types of transceivers requires a specific adaptation to the different impedances of these instruments. The CMS33 not only measures these impedances but can alternatively effect an automatic adaptation to the most different values and thus ensures the required AF level or the correct AF analysis at the device under test.

Auto-ILS /Autopilot CMS-B38 (optional)

To test the autopilot, the CMS33 uniquely provides two RF carriers simulating glideslope and localizer in one radio tester at the same time. All standard pairs of frequencies are considered; when the localizer frequency is entered, the appropriate glideslope frequency is set automatically. The relative modulation depths of localizer and glideslope are simultaneously changed by varying the DDM value.

SELCAL

The CMS33 provides SELCAL paging of an aircraft. The coder is conveniently activated by a push of a button and the required characters can be keyed-in via a prepared keypad.

SSB

In today's avionic maintenance, SSB testing is a prerequisite for aircraft checks. Thus an SSB menu has been specifically designed for convenient and comprehensive SSB transceiver tests in the CMS33. SSB-specific measurement requirements are built-in such as a PEP meter.

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CMS 33 ID 0840.0009.34

Spectrum Monitor

The spectrum monitor permits the synthesizeraccurate display of both modulation spectra and complete band assignments. The display of the spectra can be stored and the individual spectral line demodulated.

SPECT CH	S - Local		TX-TEST
MKR-FRQ: 335.000000 M	IHz	MKR-LEV: -32.9 dB	m REF LEV
150			10 db/d scale
Hz			QUICK
	A	Ą	FREEZE
	ſ		MKR -> CF
		Minnothing	MKR -> REF LEV
	05501 MH7	15.20 1	Hz STOP
	SPECT CM MKR-FRQ: 335.000000 M 150 Hz	SPECT CMS - Local MKR-FRQ: 335.000000 MHz 150 Hz 8 8 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9	SPECT CMS - Local MKR-FR0: 335.000000 MHz MKR-LEU: -32.9 dB 150

VSWR

Measuring the adaptation of the transceiver to the antenna (VSWR) provides important information on the receiver and transmitter power of a transceiver. While both the sensitivity of the receiver and the power of the transmitter can be determined via conventional RX and TX measurements, the determination of the VSWR is necessary for checking and adjusting antenna matching.

The CMS33 permits determining the VSWR easily with the insertion unit taken off: When the insertion unit is connected, the VSWR menu is directly entered and the VSWR as well as forward and reflected power are immediately indicated by means of a large analog display.

DALIER	0.070
FORM	9.376 W
	\|	+10
POWER REFL	0.004 W
	\|- ▼ \|\|	+0.025
USUR	1.043
	+1.0	+3.5

Instrument Configuration

The CMS33 is designed as a first-line tester and is integrated in a splash-protected carrier lateral pocket bag. A accommodates the necessary accessories such as cables. VSWR insertion unit and user quide. The carrier bag is prepared for the attachment of the optional battery pack which is trickle-charged via the CMS33. This permits operating the CMS33 on-site both via the battery and by means of an external power supply. In comparison to an internal battery, this has the advantage of lower weight if battery operation is not required. Nevertheless, also an internal battery is optional available.

The carrier bag of the CMS33 protects from splash water and comfortably accommodates all necessary equipment.

The optional external battery with battery charge indication and convenient accessible sockets for VSWR, MIC/TEL and remote control

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CMS 33

The telescopic antenna for off-air measurement including the antenna cable is accommodated in the front panel cover. This cover is designed to simultaneously serve as an antenna base. The antenna cable has spacers for the comfortable and reproducable positioning of the antenna on the runway for controlled off-air tests.

The AF connections with special MIC-TEL sockets and the connection for the VSWR insertion unit are integrated in the rear panel of the CMS33. With the battery pack used, these connections are available on the front panel of the battery pack as well.

Both, the MIC/TEL sockets and the VSWR connection, are integrated on the rear of the CMS.

The optional front panel cover of the CMS33 can be used simultaneously as an antenna base and together with the integrated antenna for OFF-AIR tests.

The small and lightweight VSWR insertion unit (NAS-Z5) covers a wide frequency range

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CMS 33

Automatic Test Procedures

Preparations for Measurements

To prepare the measurements, the only thing to do is to connect the CMS33 to the external operating unit (remote-control box = RCB), to insert the memory card corresponding to the type of aircraft and to provide a power supply system. Necessary AF connections are directly applied to the CMS33. An external interface box is not required since the different terminating impedances as well as an automatic impedance matching are already integrated in the CMS33.

On the RCB display, the user is requested to enter the desired program by means of which individual subsystems (e.g. UHF1, VHF1, UHF2) can be selectively tested or an overall test of all communication and navigation equipment can be executed.

This makes the CMS33 ready for the actual measurements.

Exemplary Run of an Automatic Measurement

On the display of the CMS33 or, in the case of remote control, via the display of the remote-control box (RCB), the user is given most detailed instructions on which settings to make at the different test items (e.g. channel frequency, push to talk etc.).

These visual instructions can be supported by acoustic signals output via the intercom equipment. The automatic test is continued subsequently by the user's manual acknowledgement.

Once the settings required for the test sequence have been made, the CMS33 starts to measure. The user is then indicated the current measurement on the CMS33 display or on the one of the RCB, and the result of a tolerance analysis can be output via a pass/fail message. In case of non-conformity of measurements with settled tolerances, the user can either repeat the measurement or continue with the tests. All measurements can be stored in the test protocol and printed out later. With the measurements running automatically, the user neither requires knowledge of operating the CMS33, nor does he need to take comprehensive service literature on the instruments to be tested with him. All parameters including the tolerances are stored on the memory card.

REPORT 1 REPORT: 01 PROGRAM: 05 09-02-94 10:35 USER: DEWEY DEVICE under TEST IDENT: PTR 1751

COMMAND	PARAMETER	RESULT		TO
VHF AM TEST: PTR 1751
* TX TEST *

RF LEVEL		0.995	W	OK
RF FREQUENCY OFFSET		-0.00054	MHz	ОК
*** NODULATION CENETITUTTY	***
MOD DEPTH- 30%		20.10
AF-I EVEL1		0 025	v
		0.025	v
* DISTORTION *
1000 HZ:		1.9	2

* S/N RATIO *		38.5	dB

	****************
RA TEST PAR
* AF LEVEL *	*****************	1.412	٧	OK

* RX SENSITIVITY *		20.0	dB
RF-LEVEL		-105.2	dBm
* S/N DATTO *	******************	0.6	dn.
37N RATIO		9.0	aB
* RX DISTORTION *
1000 HZ:		1.14	4

* RX BANDWITH *		20.80	kHz
FREQUENCY ERROR		-0.70	kHz

SUTTCH ON DE LEVEL	**	105 7	den
AVAILAND REALEVEL		-105.7	dB
SWITCH-OFF RF-LEVEL		-104.5	dBm
		104.0
* TEST FINISHED *

Exemplary Test Reports for COM testing

,		COMM	AND		PARAM	IETER
***	NAV A	IDS R	AMP TE	ST ***
***	VOR R	AMP T	EST **	*
CHEC	FOR	0
CHEC	K FOR	30
ERRO	30
CHEC	( FOR	60
CHEC	( FOR	DIRE	CTION	"то"
CHEC	( FOR	DIRE	CTION	FROM
***	ILS R	AMP T	EST **	*
CHEC	< LOC	FOR	FULL L	.EFT		******
CHEC	( LOC	FOR	MID
CHEC	( LOC	FOR	FULL F	IGHT
CHEC	G/S	FOR	FULL C	OWN
CHEC	G/S	FOR	MIDDLE
CHEC	G/S	FOR	FULL I	JP
***	MARKEI	R RAM	P TEST	***
CHEC	K BLU	E LAM	IP		*********
ov
OK CHEC	K YEL	LOW L	AMP

Exemplary Test Reports for NAV testing

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CMS 33

ID 0840.0009.34

Test Routines, Programming and Software Management

All test routines are stored on a write-protected memory card. A test routine can be created on a PC including card reader at a central office or on-site at the test item using the CMS33 directly.

In both cases, creating a test routine is very simple. When creating it on the PC, the only thing to do is to enter the corresponding IEC-bus command, knowledge of programming is not required. Creation is even simpler directly at the CMS without an external keyboard: Every manual setting or measu-

The small and handy remote-control box (optional) allows for operation in confined places.

Low Cost of Ownership

The CMS33 is based on the successful CMS family. Its use with numerous aviation control authorities and armed forces guarantees high reliability.

Modern design, modular concept and the built-in selftest permit a minimal MTTR of <15 minutes.

SMD technology, manufacture according to ISO9000 and the internal calibration routines ensure a high MTBF and maximal recalibration intervals. Thus a calibration cycle of 3 years is recommended.

rement can be stored at the stroke of a key, which are then processed automatically in the order stored.

When the RCB is used, all necessary commands are directly transmitted from the memory card in the CMS33 to the remote control box via the RS232 interface.

This means that the management of software states is reduced to the memory card to be used for both items - the radio tester as well as the remote control box.

The remote control box is ideal for the use in the cockpit in combination with automatic test runs. MIC/TELS sockets conforming to standards are available for the AF adaptation to the INTERCOM equipment. Data and voice communication with the CMS33 is effected via a single cable connection.

CMS33 inclusive options: External battery, VSWR head, remote control box and the front cover with antenna

1007.8532 E-2

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CMS 33 ID 0840.0009.34

Instrument data

Timebase

Warm up time:

Temperature effect 0 to 50°C Aging

Frequency accuracy

Receiver measurements

Signal generator Frequency range

Frequency resolution Frequency error Level FM, φM, CW

Level resolution Fine variation of level FM, φM, CW AM Level error Harmonics Nonharmonics

Residual AM (CCITT, RMS) Residual FM (CCITT, RMS) 0.4 to 250, 500 to 1000 MHz 250 to 500 MHz Phase noise

Modulation

Frequency range

AM modulation depth Resolution Mod. frequency range Mod. distortion (m <0.8) ¹⁾ Mod. error (m <0.8) ¹⁾

FM deviation

Resolution

Mod. frequency range External modulation Mod. distortion Mod. error

1) fine level variation 0 dB

0.4 to 1000 MHz usable from 100 kHz 10 Hz same as timebase

Frequency within limits

<1 x 10^-6

≤5 x 10^-8/dav

≤5 x 10^-7/month <1 x 10^-6/year

5 min from switch on at 0 °C

1 min from switch on at +30 °C

-128 to 0 dBm -128 to -3 dBm (depending on modulation depth) 0.1 dB

0 to -19.9 dB, non-interrupting 0 to -4.9 dB, non-interrupting ≤2 dB¹⁾ ≤-25 dBc ≤-50 dBc (>5 kHz from carrier, level -3 dBm) ≤0.03%

≤10 Hz ≤5 Hz ≤-110 dBc/Hz (20 kHz from carrier)

0.4 to 1000 MHz usable from 100 kHz 0 to 90% 0.5% DC to 20 kHz, ±2 %, f_AF = 1 kHz ±5 % + resolution + residual AM, f_AF = 300 Hz to 3 kHz 0 to 100 kHz (f_RF = 250 to 500 MHz, 0 to 50 kHz) 1 Hz, Δf <100 Hz 1%, Δf ≥100 Hz 20 Hz to 20 kHz 20 Hz to 100 kHz ≤1% (f_AF = 1 kHz; Δf = 10 kHz) ±5% + resolution + residual FM

φM deviation (internal)

Resolution

Mod. frequency range Mod. distortion Mod. error

Modulation modes

AM ext default

Distortion meter, SINAD meter, AF frequency counter

AF voltmeter Frequency range

Measurement range

Resolution

Error ²⁾ Input impedance

Transmitter measurements

RF power meter Frequency range Measurement range Resolution

Error (P >20 mW, AM = 0%) Selective level measurement Level range

VSWR meter

Frequency range (NAS-Z5) Measurement range Error Operating modes

0 to 10 rad (f_RF = 250 to 500 MHz, 0 to 5 rad) 1 mrad, Δφ<0.1 rad 1%, Δφ≥0.1 rad 100 Hz to 6 kHz ≤1% (f_AF = 1 kHz; Δφ= 1 rad) ±5% + resolution + residual φM

internal (single-tone/two-tone), external, internal + external 1 mV @ 1 kHz produces 35% modulation

see transmitter and receiver measurements

Frontpanel: 20 Hz to 20 kHz TEL 1/2: 50 Hz to 20 kHz Frontpanel: 0.1 mV to 30 V TEL 1/2: 0.1 mV to 20 V 100 µV, V <10 mV 1%, V ≥10 mV ±3% off reading, at 1kHz Frontpanel: 1MΩ TEL 1/2: switchable to 150Ω, 300Ω

1.5 to 1000 MHz 5 mW to 125 W ³) ⁴) 1 mW, P <100 mW 1%, P ≥100 mW ±10 % + resolution in frequency range 1 to 1000 MHz -60 to +50 dBm without weighting filter, -80 to +50 dBm with 2 kHz resonance filter

70 to 1000 MHz 1.1:1 to 10:1 <10 % of reading direct display of forward and reflected power and VSWR

2) without weighting filters 3) 80 W continuous; 125 W for 2 minutes, then 10 minutes off 4)Audio/visual warning in the event of overload

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CMS 33

ID 0840,0009.34

RF frequency counter

Frequency range Input level range (input 1) Sensitivity of input 2 Resolution

0.4 to 1000 MHz 5 mW to 125 W^{3) 4)} 0.1 uW 10 Hz. 1 Hz same as timebase + resolution

Frequency deviation meter

Operating modes

Input level range RF frequency range Deviation measurement range AF frequency range

Resolution

Residual FM (CCITT_RMS) 0.4 to 250, 500 to 1000 MHz 250 to 500 MHz

Phase deviation meter

Operating modes Input level range RF frequency range Phase deviation measurement range AF frequency range Resolution

Error²⁾

AM depth meter

Operating modes Input level range RF frequency range AM depth measurement range 0.01 to 90 % AF frequency range Resolution

Residual AM (CCITT, RMS) Error (m ≤0.8)²⁾

Distortion meter. SINAD meter AF frequency counter

RF spectrum monitor

Frequency range Reference level

2) without weighting filters 3) 80 W continuous; 125 W for 2 minutes, then 10 minutes off

+PK -PK +PK/2 PK HOLD RMS RMS*√2 5 mW to 125 W 3) 4) 1.5 to 1000 MHz 0 Hz to 25 kHz 20 Hz to 20 kHz (DC-coupled at demodulator output) 1 Hz. ∆f <1 kHz 1 % AF>1 kHz

<10 Hz ±5% + resolution + residual FM

+PK, -PK, ±PK/2, RMS, RMS*√2 5 m/N/ to 125 /N/3) 4) 1.5 to 1000 MHz

0.001 to 5 rad 300 Hz to 6 kHz 0.001 rad. ∆ω≤0.1 rad 1%, ∆ø >0.1 rad same as frequency deviation meter +2% frequency response

+PK. -PK. ±PK/2. RMS. RMS*√2 20 mW to 125 W³) 4) 1.5 to 1000 MHz 20 Hz to 20 kHz 0.01 % m <0.1 0.1 %. m ≥0.1 ≤0.03 % ≤7% + resolution + residual AM (fAF = 0.3 to 3 kHz)

see transmitter and receiver measurements

1 to 1000 MHz +50 to -47 dBm (input 1)

Display dynamic range >60 dB (for reference level >-7 dBm at 0 (zero span) to 50 MHz Filters (3-dB bandwidth) 150 Hz, 6/16/50/300 kHz, coupled to snan <3 dB + resolution Resolution

Transmitter measurements at 2nd RF input

Measurement of RF frequency, modulation, (AM, FM, φM), modulation frequency and RF spectrum (level) of small RF signals, e.g. in off-air or module measurements, for input levels from about

RF frequency counter 100 µV (selective frequency counter with presetting) Modulation meter 20 uV (IF narrow) 10 uV (IF narrow selective -70 to -35 dBm without weighting filter. -90 to -35 dBm with 2-kHz resonance filter

Transmitter and receiver measurements

Modulation generator I and II

Frequency range Frequency resolution Output level range

Max output current Resolution

Output impedance

Distortion

Distortion meter / Modulation distortion 100 Hz to 5 kHz (in 10-Hz steps)

Frequency Input level range Measurement range Weighting bandwidth

SINAD meter

Frequency Measurement range Input level range Resolution Weighting bandwidth Error

100 Hz to 5 kHz ±10 Hz 0 to 46 dB 100 mV to 30 V ≤12 kHz ±1 dB @ 12 dB

Frontnanel: 20 Hz to 20 kHz MIC: 100 Hz to 10 kHz 0.1 Hz same as timebase + 1/2 resolution Frontpanel: 10 µV to 5 V EME MIC: 100 µV to 350 mV 20 mA _peak 10 μV. V <1 mV 1%, V ≥1 mV ±5%, V >1 mV Frontpanel <5 Q

MIC: automatic impedance matching

and impedance measurement

for loads 50 to 400 Ω

100 mV to 30 V

0.1 to 100%

<0.5%

+5%

<0.5%

Page 34

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CMS 33

ID 0840.0009.34

AF frequency counter		Lowpass	fcutoff = 3.4 kHz, attenuation at
Operating modes	demodulation, AF, beat (frequency offset), external		10 kHz typ. 40 dB
Frequency range	20 Hz to 500 kHz	Bandpass broadband	highpass + lowpass
	(superimposed RF)	narrowband	50 Hz to 5 kHz
Input level range	10 mV to 30 V, f ≤20 kHz		in 10-Hz steps, attenuation
Resolution	1 Hz/0.1 Hz		typ. 40 dB for 0.8f and 1.2f
Error	same as timebase + resolution	IF filter	150 kHz
Enter		Notch filter	100 Hz to 5 kHz
Signal + Noise to Noise			in 10-Hz steps, attenuation
Manager and a second se	0 to 48 dB		typ. 40 dB for 0.8f and 1.2f
Measurement range		CCITT filter
Accuracy	±5% of reading + resolution
Ossillassana		Selective call coder
Oscilloscope	DO: DO to 20 kHz	Tonesequences	SELCAL/ZVEI1/ZVEI2/CCIR/
Bandwidth			EIA/EEA/EURO/NATEL/CCITT/
			VDEW/VDEW direct dialling /
Horizontal deflection	50 to 0.05 ms/div		user-defined sequences
Vertical deflection	scaled in KHZ (FM), rad (qM), %
	(AM), mV/V (AF)	Audio monitor (loudene	aker)
Input level range	0 to 40 V _p	Audio monitor (loudspe
Input impedance	approx. 1 MΩ
			beat (frequency offset)
AF filters
Highpass	f _cutoff = 300 Hz, attenuation at 200 Hz typ. 40 dB	Impedance matching	see page 6

VOR/ILS generator ⁵⁾

General

The Localizer and Glideslope carrier frequencies have the capability of varying the modulation depth of the 90 Hz and 150 Hz tones, thus displaying fly left/right and up/down indications on the aircraft displays. To test the operation of the flag alarm the test set has the capability of deleting either the 50 Hz or 150 Hz tones. The Marker Beacon is simulated by transmitting a 75 MHz carrier modulated by one of the 3 AF tones. VOR signals are simulated by modulating a VHF carrier with 2 separate 30 Hz tones, the phase of one being variable with respect to the other. Localizer and Glideslope frequencies have specific pairings and the test set automatically selects the paired Glideslope frequency when a Localizer frequency is selected.

Range	Resolution	Error

-128 to 0dBm dependent on modulation depth
108 to 117.95 MHz		±0.0035% (0 to 35 °C) ±0.005% (0 to 50 °C)
Odd / Even 100 kHz spacing
0 to 360°	0.01°	±0.06°
0 to 360°	0.01°	±0.04°

7.9 to 12 kHz

0 to 100%	0.1% AM	±2% for 30% AM
0 to 100%	0.1% AM	±2% for 30% AM
384 to 576 Hz	1 Hz	≤1 Hz

24 to 36 Hz

0 to 100%	0.1% AM	±2% for 30% AM
0 to 100%	0.1% AM	±2% for 30% AM
	Range -128 to 0dBm dependent on modulation depth 108 to 117.95 MHz Odd / Even 100 kHz spacing 0 to 360° 0 to 360° 7.9 to 12 kHz 0 to 100% 384 to 576 Hz 24 to 36 Hz 0 to 100%	Range Resolution -128 to 0dBm dependent on modulation depth 108 to 117.95 MHz

5) Data for VOR/ILS/MB signals are specified in the RF level range (-128 to -12 dBm, fine variation 0 dB) for discrete RF frequencies as well as for the following continuous ranges: VOR: 108 to 118 MHz; ILS localizer: 108 to 112 MHz, ILS glideslope: 329 to 335 MHz: Marker beacon: 74 to 76 MHz

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CMS 33

ID 0840.0009.34

	Range	Resolution	Error
1020-Hz AUX	-
Modulation frequency	50 Hz to 20 kHz
Amplitude modulation	0 to 100%	0.1% AM	±3%, at 1	1020 Hz and 10 to 20% AM
Switchable TO or FROM
ILS
90-Hz and 150-Hz phase	0 to 180°, referred to 150 Hz	0.01°	±0.1°
90-Hz tone	,
Modulation frequency	72 to 108 Hz
150-Hz tone
Modulation frequency	120 to 180 Hz
1020-Hz tone (AUX)
Modulation frequency	50 Hz to 20 kHz
Amplitude modulation	0 to 90%	0.1% AM	±3%, at 1	1020 Hz and 10 to 20% AM
II S Localizer
Amplitude modulation
-128 to -12 dBm	0 to 50%	0 1% AM	+2% for 1	20% AM
-88 to -48 dBm	0 to 50%	0.1% AM	+2% for	20% AM
DDM ⁶⁾ RE output	+0 to 0.4 DDM	0.170 AW	12 10 101 1
	for 20% AM
On-course error, -128 to -12 dBm			<0 0004	DDM
Off-course error, -128 to -12 dBm			+2% + 0	0004 DDM
			for IDDM	∥ ≤0.2
DDM ⁶⁾ AF output	±0 to 0.4 DDM	0.001 DDM	±3% + 0.	0002 DDM
and the stand of the stand protons.	for 20% AM		for \|DDM	\|\| ≤0.4,
			AF level	0.5 to 5 V
ILS Glideslope
Frequency Band	329.15 to 333.95 MHz		±0.003%	(0 to 35 °C)
			±0.005%	(0 to 50 °C)
Amplitude modulation
-128 to -12 dBm	0 to 50%	0.1% AM	typ. <2%	for 40% AM
-88 to -48 dBm	0 to 50%	0.1% AM	±2% for	40% AM
DDM ^o) RF output	±0 to 0.8 DDM	0.001 DDM
	for 40% AM
On-course error, -128 to -12 dBm			<0.001 D	DM
Off-course error, -128 to -12 dBm			±2% + 0.	0004 DDM
		0.004 0.004	for DDM	1 ±0.4
		0.001 DDM	±3% + 0.
	10F 40% AIM
Marker Beacon			AF level	0.5 10 5 V

Modulation frequency	400 1300 3000 Hz
Amplitude modulation	400, 1300, 3000 Hz	0 1% AM	+5% for (	95% AM
1020-Hz tone (AUX)	0 10 100 %		101
Modulation frequency	50 Hz to 20 kHz
	0 to 100%	0.1% AM	+5 % + r	esolution + residual AM
		0.1.707.000	m <0.8 f	_=300 Hz to 3 kHz
Autopilot CMS-B38	Provides additional glideslope
(optional)	bearings with the localiser
	simultaneously;
	level approx53 dBm
	frequencies: standard glideslone

AUTORUN Program

VOR / ILS / MB tests carried out automatically in the form of an auto run facility requiring only confirmation inputs from the operator.

6) Difference in Depth of Modulation; describes the modulation depth difference between the 90-Hz and the 150-Hz tone; |DDM| = |(90-Hz modulation in % - 150-Hz modulation in %) / 100%.

-14-

1007.8532 E-2

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Page 39

CMS 33 ID 0840.0009.34

SSB Measurement

Frequency range Bandwith Distortion and Noise

General data

IEEE bus

interface to IEEE 488 with listener/talker function

1 to 1000 MHz 20 Hz to 20 kHz

< 3% at 1kHz rate

in a 0.3 to 3.4 kHz BW

Rated and operating temperature range Storage temperature range Temperature load

Climatic load (damp heat)

Mechanical load

Sinusoidal vibration

Standards complied with

Random vibration Shock Standards complied with

EMC

Safety Power supply

Weight Dimensions (WxHxD)

0 to +50°C -40 to +70°C complies with IEC 68-2-1 and IEC 68-2-2 +25°C/+40°C cyclically with 95% rel. humidity; complies with IEC 68-2-30 tested to MIL-STD-28800 CAT III, class 3, style C 5 to 150 Hz, max. 2 g at 55 Hz, 0.5 g at 55 to 150 Hz IEC 68-2-6 and IEC 1010-1 as well as MIL-T-28000D class 5 10 to 300 Hz, acceleration 1.2 g rms

40 g shock spectrum MIL-STD-810C and MIL-T-28800D class 3 and 5 complies with EMC standards of EU (89/336/EWG) complies with EN 61010-1 100/120/220/240 V AC ±10%, 47 to 420 Hz or 11 to 32 V DC (50 W) approx. 14.5 kg (32 lb) 320 mm x 175 mm x 375 mm (12.6 inch x 6.9 inch x 14.8 inch)

Options

External battery pack CMS-Z42 ID.1065.5803.02 with battery condition indication MIC/TEL, VSWR socket Minimum operating time 1 h at 0° C to 50° C Weight approx 4.4 kg (9.7 lb) Dimension (WxHxD) 85 mm x 175 mm x 375mm (3.3 inch x 6.9 inch x 14.8 inch)

Autopilot CMS-B38 ID.1065.5003.02 Weight approx 0.3 kg (0.7 lb)

Antenna base CMS-Z35 ID.1066.7300.02

cover, cable and antenna Weight Dimension (WxHxD)

approx 1.6 kg (3.5 lb) 350 mm x 180 mm x 90mm (13.8 inch x 7 inch x 3.5 inch)

Remote Control Box CMS-Z34 ID.1065.4213.02

Weight Dimension (WxHxD)

approx 2.2 kg (4.8 lb) 215 mm x 53 mm x 144mm (8.5 inch x 2.1 inch x 5.7 inch)

Carrying Bag CMS-Z44 ID.1066.7400.02

Memory Card CMS-Z2 ID.0841.1509.02 128 kBvte

120 KDytt

Ordering information

Radiocommunication Service Monitor CMS33 0840.0009.34

Accessories supplied

User's guide, spare fuses, power cable (right angled), NAS-Z5 VSWR head and cable

Page 40

Page 41

2 Operation

The values stated in this section are not guaranteed; only the technical data on the data sheet are binding.

The numbers printed in bold type and italics refer to the controls shown in the front and rear views Figs. 2-1 and 2-2.

2.1 Explanation of Front and Rear Views

2.1.1 Front Panel

(see Fig. 2-1 in appendix)

Display

All information for the user is output on the display. It contains a menu heading and status line, describes the functions of the softkeys and indicates the set and measured values in digital and analog form. The information shown on the display changes depending on the selected menu.

Softkeys

16 softkeys with alternating functions. The respective function is output on the display directly next to the softkey.

Numbers have been assigned to the softkeys for referencing in the text:

Right-h softk colur	ano ey nn
	8
	9
	10
	11
	12
	13
	14
	15

-

Numeric keypad 0 to 9

For entering values. With tone sequences: numeric value for SELCAL

Dimension key with ENTER function

Frequency	MHz
Level	mV
Modulation(AM), distortion	%
With tone sequences: numeric value	А

5

Dimension key with ENTER function

Frequency, modulation(FM) Level	kHz μV
Power	W
With tone sequences:
numeric value	в

Dimension key with ENTER function

Frequency, modulation (FM)	Hz
Level	dBµV
With tone sequences:
numeric value	С

7 Dimension key with ENTER function

Quasi-dimension for relativ	/e
settings, SINAD, S/N	dB
Level, power	dBm
Modulation (φM)	rad
With tone sequences:	D
	0

Page 42

Minus sign

Every number is positive unless a minus sign is entered. Input of tone sequences:

With DTMF		#
With all oth	ner codes	F

9 Decimal point

Input of tone sequences:
with DTMF	*
with all other codes	Е

10

ENTER ON

Terminating key for all inputs which do not have or require a dimension or quasidimension.
Switching-on the functions which were switched off by OFF.

11

CLEAR

011
Abortion of commenced input strings.
Switching-off of functions
Switching-off of functions such as REF, RANGE, VAR, TOL.
Deletion of a deletable message in the 2nd status line.

12 VAR

Settings can be varied using this spinwheel. The step size and the assignment of the parameter can be defined using the function key VAR.

13

SHIFT

The keys 14 to 20 have dual functions. The SHIFT key must be pressed to reach the function printed in the top line. The softkeys 0 to 15 also have a dual function depending on the menu. The second function (top or bottom) is made accessible by first pressing the SHIFT key. The status line indicates when the SHIFT function is active.

printer. START: Execution of autorun control program
(one of the most important functions).

15

STOP: Transfer from IEC bus mode to manual mode.

The following applies in autorun control mode:

RETURN: Transfer from IEC bus mode to manual mode. Transfer from autorun control mode to manual mode.
STOP: Stop current autorun control program.

16 RECALL STORE

RECALL: Recall instrument settings. STORE: Store instrument settings.

Page 43

17

RESET

MENU ↓

RESET: Set instrument to its factory-setting. Autorun control programs are not cleared in this way.
Menu↓: Enables searching for submenus together with the active cursor in the display

22 VOLUME

Adjustment of screen contrast.

MEMORY

Plug-in for the chip card CMS-Z1 or CMS-Z2.

18 REF MENU ↑

REF: Entered or measured values are declared as reference values.
MENU ↑: Transfer to higher-level menu.

AF/SCOPE INPUT 1 MΩ

Input for all AF and DC measurements. The signals connected here can be evaluated by the AF and DC measurement points or displayed on the scope. Input resistance depends on the model or option.

19 RANGE

VAR

RANGE: Storing of full-scale value with analog display.VAR: Definition of setting increment when using VAR spinwheel.

MOD GEN

Output of AF generator.

- TOL

+ TOL

Definition of upper and lower limits. The tolerance markers are set in the analog display, and the tolerance evaluation is defined in the autorun control.

MOD EXT INPUT 1 MΩ

Input for external modulation signals, also second input for the scope.

CONTRAST

Adjustment of loudspeaker volume.

DEMOD

Output for the demodulated signal.

Page 44

23

RE IN 2

A 1 VMAX ~50 Ω 🔶

Second RF input; high sensitivity, therefore suitable for remote measurements

212 Rear Panel

(see Fig. 2-2 in appendix)

40

F2: T10 IEC127/2 Fuse for battery operation.

11

I		в
ī	ο	Ā
N	F	т
E	F	т

This switch has 3 positions: Line mode ON Line and battery modes OFF Battery mode ON

42

11...30 V DC

Connection of external DC source to instrument. Connection for battery pack with trickle charging.

4.5

Blower

The blower and the vents in the instrument housing must not be covered since both the power loss of the instrument and the output power of the radiotelephone are discharged via this blower

25

RF IN/OUT

A 125 WMAX (↔ 50 Ω

RF power input, also output for RF signals of instrument. This connector is usually linked to the antenna connector of the radiotelephone.

46

MIC/TEL1 socket

VSWR connector

TEL 2 socket

PRINTER PARALLEL INTERFACE

Printer output (Centronics).

50

4.9

CONTROL

Connection to the Remote Control Box.

IEC 625 IEC/IEEE bus connection

52

AC supply voltage selector and fuse holder IEC 127/2 - T1.6D 100/120 V: 230/240 V: IEC 127/2 - T800

53

AC power connection

47 to 420 Hz

Page 45

2.1.3 Remote Control Box

(see Fig. 2-3 in appendix)

Display

Two line display for information of the auto run program.

MIC Tel1 socket

Tel2 socket

← Selection of various values during autorun.

64 → see 63

65 ACCEPT To accept a setting during autorun.

REJECT To reject a setting during autorun.

67 REPEAT

To repeat a measurement during autorun.

CONTINUE To continue an auto run program after stop.

STOP To stop an autorun program.

START To start an autorun program

2.1.4 Batterie pack (see Fig. 2-4 in appendix)

MIC Tel1 socket

VSWR connector

Tel2 socket

Remote Control connector

Battery full indication

Charging indication

86 Battery empty indication

Page 46

2.2 Preparation for Use

Unpack the instrument and check that the listed accessories are present. Before switching on for the first time, refer to Sections 2.2.1 and 2.2.2.

2.2.1 AC Power Mode

Setting the AC Supply Voltage

Before setting the AC supply voltage disconnect the AC power supply cable!

The instrument is designed for rated AC voltages of 100 V, 120 V, 220 V or 240 V (frequency 47 to 420 Hz). Before switching on the instrument for the first time, check that the correct AC supply is set. With new instruments, the set voltage is printed on the yellow label on the AC connector. If this does not agree with the local voltage, convert as follows:

Unscrew fuse holder 52 by 1/2 rotation to the left and remove.
Remove fuse from fuse holder.
Set desired voltage (arrow). For this purpose, insert voltage selector switch and rotate.
Insert fuse with required rating (fuses included in accessories). A fuse T 1.6 D is required for 100/120 V, a fuse T800 for 230/240 V.
Insert fuse holder and lock by ¹/₂ rotation to the right.

Once the AC cable has been inserted into the connector 53, the instrument can be switched on using the rocker switch 41 on the rear panel (LINE position). The instrument is switched off when in the OFF position, even if the AC cable is connected (no standby mode but trickle charging the battery pack). The power consumption with the basic configuration is approx. 50 VA.

2.2.2 Battery Mode

An external DC supply can be connected to the connector 11... 30 V DC 42. The DC battery socket CMS-Z7 can be purchased using the ordering code 841.1350.02. The connection is made as follows:

(viewed onto soldered side)

Instrument ground + 3 for trickle charging the battery pack

Note: Connector 42 can only be inserted in one position and thus prevents incorrect polarity. The instrument is not protected against incorrect polarity, however, e.g. when soldering the battery socket.

Spare fuses for battery mode are included in the accessories.

Once the connection to the DC supply has been made, the instrument can be switched on using the rocker switch 41 on the rear panel (BATT position). The instrument is switched off when in the OFF position, even if the battery cable is connected (no standby mode). The power consumption is approx. 40 W.

2.2.3 Operating Instructions for CMS Z-42 Battery Pack 1065.5803.02

The Battery Pack is used for battery operation of the CMS 33. It consists of a splash-proof, handy cabinet accommodated in a small, highly tearresistant bag with removable transparent cover. A zip fastener over all four sides permits attachment to the CMS 33 carrying bag.

The battery pack includes two series-connected, closed lead-acid batteries requiring no maintenance as well as a battery charger with overdischarging protection.

Page 47

The DC cable with the coded DC socket of the battery pack reliably prevents unintentional wrong connection which would cause damage to the battery pack or the CMS 33.

Caution: Only connect the battery pack to the CMS 33!

As a safety precaution, a DC fuse (T10A) is located next to the charger board, which can only be replaced after opening the battery pack. A spare fuse is supplied as an accessory part.

Pin assignment of DC connector: Pin 1: - battery voltage (GND) Pin 2: + battery voltage Pin 3: + charging voltage

Furthermore, the battery pack includes the 50contact control socket for connection of the remote control box, the 8-contact VSWR socket and the MIC/TEL sockets on the front panel. These sockets are connected with the CMS 33 control socket via a cable at the rear.

Battery operation and charging of the batteries

For battery operation of the CMS 33, the DC cable provided with the battery pack must be connected to the CMS 33.

Set the switch on the rear panel of the CMS 33 to the BATT position.

In the fully charged state, the built-in batteries permit the CMS 33 to be operated for 1 hour at 0 to 50 °C. A red flashing LED indicates when the battery voltage is too low. In this case, the battery should only be used for another five to ten minutes in order to ensure a long battery life.

If an overdischarging protection is built in, the battery is automatically cut off when the discharge voltage is reached.

The battery pack must be recharged as soon as possible then!

After inserting the power plug on the CMS 33 (rocker switch in the OFF position) and connecting the DC cable of the battery pack to the CMS 33, the battery charger automatically carries out the charging process without time limit (yellow LED illuminated).

A completely discharged battery must be charged for approx. 12 to 14 hours in order to achieve a state of charge of approx. 90%.

To achieve full capacity, charging should continue for some more hours (green LED starts to light).

The battery charger is equipped with a permanent charging facility, which compensates for self-discharge of the battery, making sure that fully charged batteries are always available (trickle charge).

After unintentional overdischarging (battery pack has not been recharged over a longer time period after discharging) - > self-discharging) the battery pack can be recharged by prolonging the charging time (yellow/green LED are not illuminated first, since only a small charging current is used with a low battery voltage!).

However, a discharged battery should not be kept longer than a few days without being recharged.

A fully charged battery features extremely little self-discharging; recharging of a fully charged battery is required after 9 months at the latest at a storage temperature of + 20 °C.

At low temperatures, recharging is only required after a longer time period, whereas it is necessary at shorter time intervals at higher temperatures.

To make sure that the battery is fully charged and ready for use at any time, the charger should always be connected to the power supply. Overcharging of the battery is not possible due to the voltage-limited charging technique.

Operating and storage temperatures

The operating temperature range extends from 0°C to +50°C with the battery capacity being reduced by up to 20% at low temperatures. If the battery is fully charged, the storage temperature extends from -15°C to + 40°C.

Caution: Due to a reduction in the specific gravity of the electroyte, only fully charged batteries may be stored at low temperatures.

The batteries should be stored in dry rooms (50% humidity) at temperatures ranging from 0°C to + 35°C, if possible!

Page 48

Battery replacement and lifetime

If the batteries are properly stored and charged, they feature a max. lifetime of approx. 200 charging and full discharging cycles.

Use only batteries from Rohde and Schwarz order no. 1077.944 and replace both batteries at the same time. Make sure to dispose of lead-acid batteries properly!

Possible dangers

Keep batteries away from fire.

Do not short-circuit the terminals.

Do not open batteries.

If the battery is damaged and diluted sulphuric acid comes into contact with the skin or clothes, the affected area should immediately be washed with water.

If diluted sulphuric acid gets into your eyes, immediately wash them with large quantities of water and contact a doctor.

A discharged battery should be recharged as fast as possible.

In any case, read through the instructions before using the battery.

Page 49

2.3 Operation

The instrument functions are possible in three main operating modes:

Manual operation
Autorun control
Remote control via IEC/IEEE bus.

2.3.1 Power-Up Status

A selftest including various internal operating point adjustments is carried out following power-up. The selection menu is output in the display if no errors are detected, otherwise the corresponding error message is output (cf. Section 2.11.11).

The instrument is equipped with a back-up battery so that the set parameters and measured values are retained when the instrument is switched off or in the event of a power failure. Only the settings for the selection menu and RF and AF levels do not correspond to the status prior to switch-off. This is for clarity reasons as well as for the safety of devices under test and the instrument itself.

A status independent of the previous settings is achieved using the keys SHIFT RESET. Apart from data entered by the user (such as e.g. tone sequence frequencies), this state corresponds to the state when delivered.

If the RESET key is actuated and retained during switch-on, all data entered - except for the autorun control programs - are reset (factorysetting).

2.3.2 Controls

The instrument controls comprise the keys and the VAR spinwheel 12 .

All instrument outputs with respect to manual operation are on the display 1 .

2.3.2.1 Softkeys

The softkeys have alternate functions. The respective function is output on the display directly next to the softkey. Together with the display, the softkeys are the main elements for menu operation.

Maximally two functions are output on the display next to a softkey depending on the menu.

The function indicated in inverted form (light characters on dark background) is applicable; the other function can be selected using the SHIFT key 13 or by pressing again the same softkey.

2.3.2.2 Hardkeys

2.3.2.2.1 Function-based Hardkeys

An active cursor on the display () indicates the current function. The hardkeys refer to this function.

Function-based hardkeys:

RANGE, VAR, REF, -TOL, +TOL, MENU ↓ (DOWN), dimension keys, ENTER, CLEAR

Examples of hardkey applications:

RANGE

The full-scale value of the analog display usually matches itself to the measured value (autoranging). It is sometimes necessary to fix this value during adjustments.

RANGE/ENTER The full-scale value is held at the current value.

RANGE/CLEAR Autoranging becomes active again.

RANGE/number/ENTER

The full-scale value is the entered number or next higher number in steps of 1-2-5. The dimension corresponds to that in the display.

RANGE/number/dimension

The full-scale value is the entered number or next higher number in steps of 1-2-5 with the selected dimension.

To indicate that the RANGE HOLD function is switched on, the full-scale value on the analog display is inverted.

Page 50

The VAR spinwheel can be used to vary set parameters. The VAR function is used to define the variation increment and the associated function.

Unless a specific VAR operation is made, the function of the spinwheel always corresponds to the current setting parameter with display of VAR symbol • (see Fig. 2.3-1).

VAR ENTER

The VAR spinwheel is assigned the selected function; it can only be changed by VAR or VAR ENTER with another function. At the same time, the VAR symbol • is changed to •.

VAR/CLEAR Cancellation of fixed assignment.

VAR/number/ENTER Sets a desired variation increment. The dimension corresponds to that in the display.

VAR/number/dimension Sets a desired variation increment. The dimension corresponds to that in the display.

VAR/0/ENTER Selection of minimum increment.

Exceptions:

In the case of a frequency setting on the modulation generators 1 and 2, the VAR spinwheel is used to vary frequencies from a fixed series.
The VAR function is automatically assigned to certain functions (time, amp. and Y pos. on the scope) without the user having to press the VAR key.

The assignment of the VAR function is identified in the display by a symbol.

If a parameter which is assigned the VAR function is switched off using OFF, rotating of the VAR spinwheel has no effect.

The output of measured values or settings on the display can be absolute or referred to a reference value.

Measurements which are always relative values (SINAD, S/N) cannot be referred even further to a reference value. Frequencies are indicated as a frequency difference relative to the reference value. All other relative displays are in dB.

REF/ENTER

REE

The current value is defined as reference value.

REF/number/ENTER

The number is defined to be the reference value. The dimension of the reference value corresponds to that in the display.

REF/number/dimension The number with the dimension is defined to be the reference value.

REF/CLEAR Return to absolute dimension.

Identification of relative displays:

The quasi-dimension dB is a relative display. In the case of frequencies, the sign (also +) shows that relative frequencies are displayed.

The analog display has a special feature in the case of relative dimensions or quasi-dimensions:

The 0 point is always on the left.

Either the right-hand half of the axis is shown with a positive full-scale value or the left-hand half of the axis with a negative full-scale value depending on the current measured value. The full-scale value is always displayed on the right, however.

VAR

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TOL

Entered tolerance values have two effects:

Limits are entered on the scale of the analog display. They serve for optical orientation during adjustments.
They enable an evaluation during autorun control depending on the result: tolerance in or tolerance out.

+/- TOL/ENTER

The current measured value becomes the tolerance limit.

+/- TOL/number/ENTER The entered number is defined to be the tolerance limit. The dimension corresponds to that in the display.

+/- TOL/number/dimension The entered number with dimension becomes the tolerance limit.

+/- TOL/CLEAR Deletion of tolerance markers.

Special features:

The two tolerance markers are not always visible.

A tolerance marker is not displayed if it is above the full-scale value. If one tolerance limit is above 0 and the other below 0 in the case of a relative display, not more than one tolerance marker will be visible on the screen because only one of the two branches (either above 0 or below 0) can be displayed depending on the measured value.

Take care with the sign when selecting the tolerance marker if a relative dimension is present:

e.g. -105 dBm is smaller (-TOL) than -95 dBm (+TOL).

MENU ↓ (DOWN)

If the function which the active cursor points to in the display has a submenu, this is indicated in the status line by an arrow pointing downwards. The corresponding submenu is selected by pressing the MENU $\pressing key, and a further submenu can be called if present by pressing again. (MENU $\pressing UP): return to status existing before MENU $\pressing (DOWN) was entered).

Dimension keys

For settings:

Number/dimension Setting of value including dimension.

Dimension Conversion of set value into selected dimension.

With measurements:

Dimension Representation of measured value in selected dimension.

Entered dimensions are modified by the instrument automatically if the desired dimension is not compatible with the display format.

Exception:

When entering tone sequences, the dimension keys have the significance of digits. The termination function is also cancelled in this context. Tone sequence entries are terminated by the ENTER key.

ENTER, ON

The ENTER key terminates input strings.

These can be commands (REF/ENTER), or also inputs. The ENTER key is used if the dimension is to remain unchanged or if the entered value has no dimension. ENTER can also be used to restore set values previously switched off by CLEAR.

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CLEAR, OFF

The 4 functions of CLEAR are:

Abortion of a commenced input string.
Switching-off of hardkey functions such as REF, RANGE, VAR or TOL.
Switching-off of set values; particularly suitable for relative settings with a logarithmic scale since the number "0" has the meaning "Reference value" in this case and not the meaning "Off".
Deletion of a deletable message in the second status line.

2.3.2.2.2 Mode-related Hardkeys

The instrument can be operated in 6 different modes:

Manual operation mode IEC/IEEE bus mode (remote) Autorun control RUN mode Autorun control HOLD mode Autorun control LEARN mode Autorun control AUTORUN menu

The functions of the hardkeys START, RETURN and STOP correspond to the instrument mode selected.

IEC/IEEE bus mode (Remote)

STOP

Allows for entering the manual mode providing RWLS (remote with lockout state) was not set. (Meaning : local).

Autorun control: RUN mode

STOP

Results in leaving the RUN mode and entering the HOLD mode.

Autorun control: HOLD mode

START

The autorun control enters the RUN mode and continues the program. (Meaning: continue).

STOP

Change from HOLD mode to manual operation. (Final stop)

RETURN Entering the AUTORUN menu of autorun control.

Autorun control: LEARN mode

START Start of LEARN mode.

Learn mode commences in the selection menu when it is called for the first time. It commences in the last processed menu if it is called again.

Autorun control: AUTORUN menu

START

Start of selected program (new start in contrast to continue).

2.3.2.2.3 Independent Hardkeys

The hardkeys described here always have the same meaning.

SHIFT

A key pressed upon entering SHIFT selects the second function. This is the function indicated in the top line on the hardkeys. With the softkeys, this is the function with the non-inverted label, which can be output in the display next to the corresponding softkey in the top or bottom line.

CLEAR

Cancels an unintentional input of SHIFT.

RESET

Sets the instrument to a defined initial status. Only user-specific parameters such as the assignment of tone frequencies to digits or programs are retained.

MENU 1 (UP)

Return to next higher menu. This key has no effect in the selection menu.

STORE

This key has 2 functions:

In the autorun control (LEARN mode), completely entered commands are stored in autorun control programs. The STORE key has a terminating function in this case.
In addition, instrument states are transferred to the memory using the STORE key. Syntax: STORE/number/ENTER

Numbers 1, 2 or 3:

Internal storage of complete instrument settings.

Frequencies for AF1 are stored only if the function AF COUPL (submenu DIST/SINAD, DIST) is off.

Numbers 4 to 9:

Storage of instrument settings on the memory card.

Numbers 20 to 39 (two-digit): Storage of RF frequencies.

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RECALL

The RECALL function corresponds to the STORE function.

The internally-stored instrument status is set by entering RECALL/number (single-digit)/ENTER

The stored frequency is output in the status line by entering RECALL/number (two-digit) and can be accepted using ENTER or deleted

using CLEAR.

The STORE and RECALL functions can also be integrated in an autorun control program.

Example:

10/MHz	STORE	STORE/3/ENTER	STORE
Set 10 MHz	Imple- mentation in an autorun control program	Store RF setting in memory 3	Imple- mentation of storage pro- cedure in the autorun con- trol program

H.COPY

Produce hard copy of current display on a printer.

2.3.2.3 VAR Spinwheel

In contrast to specific entry of parameters using the keys, the VAR spinwheel is used for parameter variation. Its function is very similar to that of the VAR key (see function-based hardkeys (VAR), Section 2.3.2.2.1). The VAR spinwheel can either be specifically assigned to a desired function or can be assigned to the current function. The variation is possible in any step sizes, also logarithmic. The setting values are increased by rotating clockwise and decreased by rotating counterclockwise. The VAR spinwheel is automatically assigned to the scope functions amplitude, time and Y-position.

Special features of VAR spinwheel:

The input VAR/0/ENTER does not lead to the minimum increment in the case of a frequency setting on modulation generators 1 and 2. In this case, frequencies from a fixed series are varied using the spinwheel:

0.3 /0.6 / 1 / 1.25 / 2.7 / 3 / 6 / 10 kHz (default settings)

The VAR spinwheel has no effect (even in background mode) if it is used on a set value which has been switched off using OFF.

If RF levels are reduced using the VAR spinwheel, these settings differ from the corresponding direct key entries in the following manner:

The spinwheel variation utilizes the interruptionfree, electronic reduction in level as far as possible (-19.9 dB with FM and $\phiM$, -4.9 dB with AM), whereas the mechanically switched attenuators are used as far as possible to set the level with a key input.

Entry of level via keys:

Best possible broadband S/N ratio, but interruption in level when changing (audible switching of attenuator set).

Entry of level using the VAR spinwheel: Interruption-free level variation, e.g. for squelch measurements.

In contrast to all other settings, an analog display is also provided for the RF level setting. This represents the interruption-free level fine variation (when reducing from right to left).

In the case of the two-function softkeys (e.g. COUNT/SET RF), when the VAR spinwheel can only be used for one of the softkey functions, the activated VAR symbol is displayed also if the softkey function without possible VAR operation is selected.

2.3.2.4 Display

The functions of the display are to indicate user inputs, to display setting and measured values in analog and digital form and to describe the respective function of the softkeys.

Status lines

The operating mode of the instrument is described in the top status line. The second status line contains messages.

Softkey inscriptions

The respective function of the softkeys is output at the right-hand and left-hand margins of the display, directly next to the softkeys. The function displayed in inverted form is currently active. If the softkey is assigned two functions, the second function can be activated using the SHIFT key. The active cursor is positioned next to one of these fields (see fig. 2.3-1). It marks the function which can be manipulated by entering values or by using the function-based hardkeys (see Section 2.3.2.2.1).

The VAR symbol • is changed to • if the adjacent parameter has been set for VAR spinwheel variation.

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Representation of measured and set values

Measured and set values are output in the centre of the display. Set values are usually displayed in digital form only (exception: RF level setting with VAR spinwheel). Measured values are displayed in digital and analog form. Attributes such as RMS or PK refer to the nature of the measured value. The analog displays may be provided with tolerance markers (see function-based hardkeys (TOL), Section 2.3.2.2.1).

The submenus at the lowest position in the hierarchy usually fill a small section of the display only. These display fields overwritten by the submenu are emphasized by italic lettering.

The display can also copy the oscilloscope or spectrum monitor display in addition to the digital and analog outputs of individual measured values. It is only used as an editing or displaying tool in certain menus.

The display characteristics are described in detail in the individual menus.

If the CMS is not operated on for some time, the display will become dark so as to save energy (which is of particular importance when the CMS is operated from battery). It will be bright again by pressing any key. This keystroke does not have any other function then.

Fig. 2.3-1 Active cursor and VAR symbol

Page 55

2.3.3 Menu Structure

Fig. 2.3-2 illustrates the menu structure of the instrument without consideration of lower hierarchical levels.

Fig. 2.3-2 Menu structure

Ľ.

2.15

Page 56

2.3.4 Error Reaction

If erroneous operation occurs, the instrument outputs an error message in the status line and produces an audible signal, and rejects the setting. Range violations beyond the minimum value are replaced by the minimum value. Range violations above the maximum value are rejected in order to protect the connected device under test. The instrument also reacts to faulty test routines by display of a message and by an audible signal.

2.3.5 Connection of the Device under Test (DUT)

Fig. 2.3-3 Connection of the device under test

2.3.6 Selection Menu

After switching on the instrument the selection menu offers all main menus.

Fig. 2.3-4 Selection menu

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2.4 Transmitter Test (TX-Test)

Fig. 2.4-1 Main menu TX-TEST

Starting with the main menus of the selection menu, the main menu TX-TEST (transmitter test) can be entered by pressing the softkey TX-TEST.

This menu contains all controls required to carry out a standard transmitter test. Almost every function contains submenus. These provide controls for more transmitter test functions, which are less often required.

Softkey 0 can be used to directly branch to the main menu for the receiver test (RX-TEST).

2.4.1 RF Measurement

In the case of simple transmitter tests the instrument measures the transmitter frequency and sets the demodulators to this frequency. The receiver frequency of the instrument can also be preset if the device under test outputs several carrier frequencies or if the time for counting is insufficient for the demodulator to respond rapidly (demodulation of a fast acknowledgement).

The count function is constantly active if the COUNT field is shown in inverted form.

The counter resolution can be set using the following input sequence: softkey COUNT/number 1 or 10/terminating key Hz or ENTER. Thus 1 Hz (slow) or 10 Hz (fast) is selected as the counter resolution.

The sensitivity of the RF counter in particular with frequencies < 1 MHz can be enhanced by switching the IF filter on (FILTER submenu 2, softkey 6: IF-NARROW).

Relative counting

There are two possibilities for selecting a reference frequency for relative counting.

Input of softkey COUNT/REF/ENTER declares the frequency just measured as the reference frequency; input of softkey COUNT /REF /number /termination key dimension OF ENTER declares the entered frequency as the reference frequency.

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A sign in front of the result indicates that a relative frequency count is being carried out. Absolute frequency counting can be reselected by entering softkey COUNT/REF/OFF.

The dimensions MHz, kHz or Hz can be selected for direct or relative counting, e.g. softkey COUNT/Hz.

COUNT Function: Submenu

The function COUNT has a submenu which is output in the display fields next to softkeys 3, 4 and 5.

Fig. 2.4-2 COUNT submenu

The normal count function comprises a coarse direct broadband count and a subsequent exact narrowband IF count. The direct count is possible only at the connector RF IN/OUT, the IF count is possible at both inputs (RF IN/OUT and RF IN 2).

Softkey 3: FRQ PRESET (IF count)

A frequency count can be initiated in a narrowband range (approx. 100 kHz) by entering a frequency.

Switch	-on:	Soft	Softkey3/number/dimension
		ENTER The	R	frequency	replaces
		the c	coarse cou	unt.	replaces

Switch-off: Softkey3/OFF

Applications:

The IF count method can also be used at the input RF IN 2. If a source outputs several carrier frequencies with a sufficiently large spacing (approx. > 1.5 MHz), this method can be used to select a carrier frequency and to selectively count it. (Method of selection: see softkey 5 (FILTER:IF NARROW) in the main menu).

Note:

If the squelch function of the CMS is deactivated (submenu DEMOD), only a restricted COUNT function is possible:

OFF: no function
ON: first apply the RF signal to be measured, then press softkey COUNT.

Softkey 4: DIRECT COUNT

Switch-on: Softkey 4/number 100 or 1000/ dimension Hz or ENTER. Direct counting is carried out with a resolution of 100 or 1000 Hz, but only via the connector RF IN/OUT.

Switch-off: Softkey 4/0FF

Applications:

Measurements can be performed on relay stations even if the instrument is not equipped with a duplex modulation meter. The signal generator of the instrument stimulates the receiver of the relay station, while the direct counter determines the frequency of the relay station transmitter, which may also be in a completely different frequency band.

Softkey 5: FRQ TRANS (Transfer function)

Actuating this softkey once transfers the measured frequency as CMS receiver frequency.

In the main menu, this action switches from the COUNT function to the SET function.

Application:

Softkey 5 facilitates operation with regard to the entry of multi-digit and often unknown transmitter frequencies as CMS receiver frequency.

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SET RF Function

The receiver frequency of the instrument is fixed using the SET RF function. It is not based on the counter result. If the SET RF function is not already active (displayed in inverted form), it can be activated by entering SHIFT/softkey SET RF. The CMS receiver frequency is usually entered and displayed as a frequency value.

The CMS receiver frequency is entered using softkey SET RF/number/dimension OF ENTER.

The receiver frequency setting can be varied using the VAR function and the VAR spinwheel. The receiver frequency setting can also be relative.

The reference frequency can be entered using sofkey SET RF/REF/ENTER if the current frequency is to become the reference frequency, or using the softkey SET RF/REF/number/dimension or ENTER if a frequency is to be set different from the reference frequency.

The SET RF function has a submenu which is output in the display fields next to softkeys 3 to 7.

Fig. 2.4-3 SET RF submenu

Softkey 3: FRQ TRANS (Frequency transfer function)

Actuating this softkey switches the frequency transfer function on or off.

An activated transfer function has the following effects:

At the point of switchover from TX→RX, the RX RF frequency is calculated from the RF frequency set or counted in the TX test and the duplex spacing.
At the point of switchover from RX→TX, the TX RF frequency is calculated from the RF frequency set in the RX test and the duplex spacing, if the RF counter in the TX test is off.
When the RX RF frequency in the duplex menu is changed, the TX RF frequency continuously follows displaced by the duplex spacing, if the RF counter is off.
When the TX RF frequency is changed (by RF counter or setting), the RX RF frequency follows displaced by the duplex spacing.

Softkey 4: DUPLEX SPACE

The duplex spacing is entered by sequence sign/ number/(dimension or ENTER).

Values between -500MHz and +500MHz are possible.

The duplex spacing is positively counted if the RX RF frequency is larger than the TX RF frequency.

Softkeys 5, 6 and 7 serve to define the channel numbers.

Softkey 5: REF CHANNEL (Reference channel)

The reference channel is entered by number/

Values between 0 and 9999 are possible.

Entries are permissible only if the channel number mode is off (softkey 7).

This entry establishes reference between frequencies and channel numbers. In addition to the reference channel entry, also the respective reference frequency is displayed.

At a duplex spacing not equal to zero, the reference frequency in the TX and RX test is different. In the DX test, the reference frequency is always referred to the RX frequency.

Softkey 6: CH-SPACE (Defining of channel spacing)

The channel spacing is entered by sequence sign/ number/(dimension or ENTER).

Values between -1MHz and + 1MHz are possible.

Entries are permissible only if the channel number mode is off (softkey 7).

A positive sign means that higher channel numbers correspond to higher frequencies.

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Softkey 7: CH NUMBER (hannel number)

Actuating softkey 7 switches the channel number mode on or off.

When channel number mode is on, frequencies are only displayed as channel numbers plus offset. Reference between channel numbers and frequencies is made when the reference channel is entered.

If the channel number mode is activated in the RX or DX test, the RX RF frequency is assigned to the reference channel selected by softkey 5. The TX channel number is calculated from the TX RF frequency and the duplex spacing and displayed if present in the menu.

If the channel number mode is activated for the TX test, the TX RF frequency is assigned to the reference channel selected by softkey 5.

With VAR spinwheel variations, also the frequencies are varied in the channel number mode. This gives the offset to the channel number.

Offset also occurs if the RF counter counts frequencies that are not exactly in line with the channel spacing.

Frequencies with channel numbers below 0 or above 9999 are not indicated as channel number plus offset, but by normal frequency display.

2.4.2 Power Measurement

POWER Function

The broadband RF power measurement can only be performed at the RF IN/OUT socket; the selective RF power measurement can also be carried out at the RF IN 2 socket (input 2). The dimensions of the broadband RF power measurement are W or dBm, those of the selective RF power measurement are mV, W, dBµV or dBm.

A logarithmic relative display based on a reference value can be selected. Tolerance markers can be set on the analog bar for the dimensions mentioned above; Autorange or Range Hold can be selected on the analog display for the full-scale value.

Selective power measurement:

In this measurement mode the CMS is automatically operated in the mode BEAT mode with an IF of 2 kHz (LO frequency of the local oscillator is 2 kHz below the frequency indicated).

The demodulator is switched off. The test bandwidth is approximately the set receiving frequency ± 50 kHz.

The dynamic range is depending on the input: RF IN/OUT: approx. -62 ... + 50 dBm RF IN 2: approx. -50 ... -35 dBm

Measurement sensitivity can be increased by reducing the test bandwidth using the filters available in the CMS.

The use of the CCITT filter may cause problems as, in accordance with the definition, it features no constant attenuation characteristic in the pass band.

In contrast to the broadband RF power measurement, the selective RF power measurement also includes the Peak Envelope Power (= PEP). With AM results that are up to 6 dB higher (100%) are therefore obtained.

Calibration of the selective RF power measurement is not required.

Note: Limiting sensitivity may be reduced as a result of strong signals outside the measuring bandwidth. If the frequency of the device under test strongly deviates from the nominal frequency, the measurement may be impaired. (Remedy: Monitoring the 2-kHz beat signal by way of the loudspeaker or scope.

POWER Function: Submenu 1

Pertaining to the POWER function a submenu is available, which is assigned to the fields beside the softkeys 3 to 6 in the display.

Fig. 2.4-4 POWER submenu

E-1

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Softkey 3: PEP

The type of RF power measurement (selective or broadband) is selected using this softkey.

ON: Selective RF power measurement OFF: Broadband RF power measurement

Softkey 4: TIME

With broadband RF power measurements a lowpass filter in the measurement path is switched on (SLOW) or off (FAST) using this function. With the setting AUTO the lowpass is switched on during AM modulation; otherwise the lowpass is off. Its cutoff frequency is about 4 Hz.

Softkey 5: POWER HOLD

Storage of the maximum value is switched on when actuating this softkey, i.e. the highest measured value of each RF power measurement (selective or broadband) is stored until deletion. The maximum value is deleted by pressing the softkey 6 (POWER HLD RES) or softkey 2 (POWER).

Softkey 6: POWER HLD RES

The maximum value of RF power measurement currently stored is deleted provided that softkey 5 (POWER HOLD) is activated.

VSWR - Voltage Standing Wave Ratio

VSWR measurement comprises the determination of the forward and reflected power and the calculation of their ratios (VSWR).

VSWR measurement is effected using a measuring head (NAS-Z1, Z3, Z5, Z6, Z7) which is connected at the rear of the CMS via a sub-D cable at the 50-contact connector.

The measuring head, which is inserted between transmitter and antenna, determines the forward and reflected voltage. An analysis of the data supplied by the measuring head is effected in the CMS, with an additional indication of the ratios of the two voltages.

VSWR measurement is executed within the TX test.

After the VSWR measurement has started, the values of the forward and reflected voltage as well as the ratio of these two values are indicated one below the other. These values are indicated in digital form with an additional representation on the analog bar.

POWER Forw	15.6 dBm
	├	-25
POWER REFL	1.7 dBm
	\|	+2.5
USUR	1.505
	⊢ ₹ i i +1.0	+3.5

Fig. 2.4-5

Functions "TOL" and "REF" cannot be used for the indication of the VSWR value. A change of unit is neither possible in the indication of this value which has no unit. Further, the analog bar scaling of the VSWR result always starts with 1.


ACP Function
	Ì

Adjacent Channel Power Measurement (ACP)

This function is not available in the CMS 33.

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2.4.3 Demodulation

Softkey 3 is assigned two functions:

DEMOD (continuous demodulation) PK HLD (demodulation with peak hold function)

The first or second function is selected using the SHIFT key.

DEMOD Function

The instrument is able to demodulate the transmitter signal according to AM, FM or p M. One of the three demodulation modes is selected by the following input:

softkey DEMOD/dimension. FM demodulation is then used for the dimensions Hz and kHz, AM demodulation for % and $\phi$ M demodulation for rad.

Different weighting modes can be selected in the submenu. If peak weighting is selected, the positive and negative peaks are displayed at the same time. Tolerance markers and decision criteria such as e.g. branching in the autorun control program always refer to the positive peak value, however. The RMS weighting generates only one measured value.

Modulation sensitivity

The modulation sensitivity is integrated in a search routine, which varies the AF voltage of the modulation generator at the transmitter input until a predefined modulation depth, frequency deviation or phase deviation is attained as transmitter modulation.

The entry is made using:

Softkey DEMOD/number/dimension.

The number corresponds to the entered modulation value and the dimension to the demodulation mode of the CMS.

If the demodulation mode output in the display is to be retained, ENTER can be input instead of the dimension.

The anlog display can be assigned a full-scale value depending on the measured value or a fixed full-scale value (see function-based hard-keys (RANGE), Section 2.3.2.2.1). The positive

peak value applies if the fixed full-scale value is to be derived from the currently measured value.

Tolerance markers can be entered in the analog display (see function-based hardkeys (TOL), Section 2.3.2.2.1). In the event of two measured values it is again the positive peak value which is used for the tolerance weighting.

DEMOD Function: Submenu

The DEMOD function has a submenu which is output in the fields in the display next to softkeys 4 to 7.

Fig. 2.4-6 DEMOD submenu

Softkey 4: FM DEEMPH (deemphasis)

Softkey 4 can be used to switch on or off a 750µs-deemphasis. This function is only of significance with FM selected.

Softkey 5: WEIGHT (rectifier)

Softkey 5 is used to select the detector. There are five different possibilities:

AUTO: Noise signals are RMS weighted and wanted signals are peak weighted. Small signals are automatically considered to be noise signals and large signals to be wanted signals.

The limit (RMS) is 200 Hz frequency deviation for FM 0.2 rad phase deviation for φM 1 % modulation depth for AM.

PK: Simultaneous positive and negative peak-value measurements.

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RMS: Real RMS measurement.

√2 * RMS: Real RMS measurement multiplied by 1.41.

This measurement is used for determination of the peak value when modulating with sinewave signals, and the integrating effect of the RMS detector is to be used at the same time (e.g. with noisy signals).

± PK/2: Average of positive and negative peak-value measurement.

Softkey 6: AVE LEVEL (averaging factor)

Softkey 6 can be used to select an averaging factor for RMS and 1.41 RMS measurements. Four averaging possibilities are provided.

1: One measurement determines the result.
2: The result is the average of two measurements.
3: The result is the average of three measurements.
4: The result is the average of four measurements.

Each single measurement corresponds to the average of 5 AD measurements.

in IEC bus mode, the single measurements are repeated following a delay time in the case of large changes in signal level.

The peak-value measurement is always performed with one cycle only.

Averaging factors are selected if reproducible results or a constant analog display are desired despite noise. The repetition rate of the measurements is of course reduced with high averaging factors.

Softkey 7: DEMOD (demodulator)

Softkey 7 offers the following alternatives:

OFF:Switching off demodulatorON:Switching on demodulatorSQUELCH:Activation of squelch

The squelch switches on the demodulator with a sufficiently high IF level and switches it off at a low level.

Applications:

It is recommended to have the demodulator continuously switched on for remote measurements. The squelch function is activated if the noise of the uncontrolled demodulator results in interferences (e.g. before and after a transmitter burst of limited duration).

The OFF function (demodulator off) is provided as a precautionary measure for switching off e.g. a high-level signal at the output of the demodulator to prevent interference with other sensitive measurements in the CMS.

PK HLD Function

The demodulation mode for the PEAK HOLD function is based on the DEMOD function. Pressing the PK HLD softkey resets the display and stores the largest measured value of the positive peak-value meter until cleared again.

It is also possible with PEAK HOLD to program the full-scale value of the analog display just as with DEMOD. The setting of tolerance markers is also possible.

Using the functions "750-µs deemphasis" and "Squelch" of the demodulator from the DEMOD submenu with the PEAK HOLD function is also advantageous.

Nevertheless, a submenu has not been produced for PEAK HOLD so that functions from the main menu which are used particularly frequently together with the PEAK HOLD function, e.g. decoding of a tone sequence, are not covered by the submenu. If these functions are required, they can be set in the DEMOD submenu and used for the PEAK HOLD function.

See Section 2.9 for further special functions.

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2.4.4 AF Measurement

Softkey 4 is assigned two functions:

DECODE (tone sequence decoding) COUNT (frequency measurement of demodulated or beat signal)

The shift key is used to select between first and second function.

The tone sequence decoder is activated following actuation of Softkey5/ENTER. A decoding result is deleted if present in the display and the tone sequence decode expects a sequence for decoding. Once this has arrived, it is output in two lines on the display together with the designation of the standard.

The digits 0 to 9 and possibly the special characters A to F are displayed, and also * and # with dual-tone sequences. X indicates a non-decodable frequency and P indicates a pause. The PEAK HOLD function is activated together with the decoding function since the modulation is usually also of interest in addition to the contents of the tone sequence.

The function DECODE branches into two submenus, which are output in the display fields next to softkeys 3 to 7. By pressing ENTER, the decoder can also be started from this menu.

3	PREU	No Id	T[ms]	Frq[Hz]	Devi[%]
4	TONE NUMBER	00 1 01 2	70 70	1060.7	0.0 0.0
		02 3 03 4	71 71	1272.2 1401.1	0.1 0.0
		04 5 05 6	74 69	1533.2 1672.8	0.1 0.1
7	NEXT	06 7	70	1832.8	0.1

Fig. 2.4-7 DECODE submenu 1

This submenu reads out the contents of the decoded telegram in more detail. Each entry in

the measurement buffer is identified by a sequential number starting with "0".

The column "T" gives the measured duration of each displayed tone.

With the tone sequence standards 1 to 9, additionally the frequency measured for each received tone is displayed in the column "FRQ [Hz]", as well as the deviation from the rated frequency in percent in the column "Devi [%]". No information will be shown for invalid tones or tone pauses or, as the case may be, dual tones. Restarting the decoder in submenu 1 causes the data of the new telegram to be output sequentially - beginning with "0" - when the tone sequence has been received completely.

Softkey 3: PREV (Page down)

The display pages down to the previous page. This softkey has no function when the first page is already displayed.

Softkey 4: TONE NUMBER (Printing of individual lines)

By programming <TONE:NUMBER value>, the contents of a respective line can be printed in the report. If no value is entered, all the lines are printed in form of a table.

Softkey 7: NEXT (Page up)

The display pages up to the next page. This softkey has no function if the last tone that was decoded is already shown.

Remargue:

Fig. 2.4-8 DECODE submenu 2

840.0009.33

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Softkey 3: DECODE (tone sequence standard)

Softkey 3 is used to select the tone sequence standard. The entry is made using softkey 3/number/ENTER where each number is assigned a tone sequence standard.

Tabell	e 2.4	-1

Standard number	unmodified	modified
0	Std.0 Fixed Frequencies	Std.0
1	Std.1 ZVEI 1	Std.1
2	Std.2 ZVEI 2	Std.2
3	Std.3 CCIR	Std.3
4	Std.4 EEA	Std.4
5	Std.5 EIA	Std.5
6	Std.6 VDEW	Std.6
7	Std.7 EURO	Std.7
8	Std.8 CCITT	Std.8
9	Std.9 NATEL	Std.9
10	Std.10 DTMF	Std.10
11	Std.11 VDEW direct dial

Standards 1 to 9 are the most common singletone sequences. To differentiate between unmodified and modified tone sequences, the CMS outputs the standard number and name in the display or, with modified tone sequences, only the standard number.

The assignment of frequencies to numbers is displayed in the definition menu for tones and can also be modified. Standard 0 reacts like a completely normal tone sequence standard. In this case the frequencies are the fixed frequencies for the AF generators. Standard 10 is the dual-tone standard and cannot be modified for evaluation purposes.

Softkey 4: DIGIT REPEAT

Softkey 4 can be used to switch on/off the digit repeat. Since tone length information cannot be used for evaluation purposes, a double digit is not represented by an extra-long tone but by a tone followed by a further tone (tone E) as the repeat tone. The double digit appears with the digit repeat function switched on, the digit and the special character E appear with the digit repeat function switched off.

Softkey 5: EVAL BNDWTH (evaluation bandwidth)

The evaluation bandwidth of the decoder is programmed by entering softkey 5/number/ENTER. The number should be selected as the magnitude in % which is permissible as a positive or negative deviation from the rated frequencies. Frequencies within this window are decoded as valid. Frequencies outside this window are marked by X.

The tolerance window should not be extended too far, especially in the case of tone sequences with narrow frequency steps, since this could lead to overlapping of the tolerance ranges and thus ambiguous decoding results.

Softkey 6: MAX PAUSE (tolerable pause)

The decoder waits for brief pauses and then continues decoding. The tone sequence is considered to be terminated if the pauses are too long, then the result is displayed. This time limit can be defined using softkey 6/number/ENTER. The dimension of the number is ms.

This pause definition must not be confused with the pause between two tones which is defined in the standard and which can be influenced in the definition menu for tones. The latter is smaller than the previously defined time limit. A "P" is set during the evaluation if only the intertone pause is exceeded.

Softkey 7: SOURCE (signal source)

Softkey 7 is used to select either the demodulator or the AF voltmeter socket (AF/SCOPE) as the decoder source.


COUNT Function

The frequency of the demodulated signal or the beat signal is counted by pressing softkey 4.

A relative measurement can be made in two different manners:

The currently measured frequency is selected as the reference frequency by entering softkey 4/REF/ENTER.
The frequency corresponding to the number is selected as the reference frequency by entering REF/number/dimension or ENTER.

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The relative result is the difference from the reference frequency. Relative measurements are identified by a sign in front of the result.

The COUNT function has a submenu which is output in the fields in the display next to softkeys 5 and 6.

Fig. 2.4-9 COUNT submenu

Softkey 5: SOURCE (Signal source)

Softkey 5 can be used to switch between the signal sources DEMOD (demodulated signal) and BEAT (beat signal).

Since the beat measurement is usually carried out with an unmodulated signal, the AF-generator of the CMS is switched off following the activation of softkey 4 (COUNT) provided that Beat is selected.

Softkey 6: MODE (Operating mode and resolution of counter)

There are two alternatives:

Period counting Gate time counting

Period counting has a resolution of 0.1 Hz up to 100 kHz; the resolution is 1 Hz at frequencies above this value. Period counting is fast but requires a signal without noise.

Gate time counting is less sensitive to noisy signals.

2.4.5 Filter Selection

FILTER Function

Various AF filters can be switched on or off using softkey 5/0N or OFF. The IF and AF filters and their characteristic frequencies can be selected in two submenus.

FILTER Function: Submenu 1

The FILTER function branches to two submenus, which are both output in the display fields next to softkeys 4 and 7.

Fig. 2.4-10 FILTER submenu 1

Softkey 4: HP 300 Hz (300-Hz highpass)

Switching the 300-Hz highpass on and off.

Softkey 5: LP 3.4 kHz (3.4-kHz lowpass)

Switching the 3.4-kHz lowpass filter on and off.

Softkey 6: PSOPH (psophometric filter)

Switching the psophometric filter on and off. The psophometric filter is a CCITT filter.

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Softkey 7: EXT FILTER

Switching the external filter on and off. An input and output for the external filter are fitted to the rear of the device (CONTROL socket 47 ; pin 10 = input/pin 42 = output).

The FILTER submenu 2 can be called by pressing the MENU $\$ (DOWN) key.

Example of an external filter

Fig. 2.4-11

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Fig. 2.4-12 FILTER submenu 2

Softkey 4: NOTCH (notch filter)

The notch filter is switched on using softkey 4/0N and off using softkey 4/0FF.

Stop frequency of notch filter:

The stop frequency of the notch filter is also selected using softkey 4. The entry is made using softkey 4/number/dimension or ENTER.

Since the resolution of the set frequencies cannot always be set as required, the actually set frequency is output in the display.

Softkey 5: RESON (resonance filter)

The resonance filter is switched on using softkey 5/0N and off using softkey 5/0FF.

Resonance frequency of resonance filter:

Softkey 5 is used to select the resonance frequency of the filter. The entry is made using softkey 5/number/dimension or ENTER. The actually set frequency is displayed as with the notch filter.

Filter combinations

For better understanding all filters can be envisaged as a series connection of three filter groups:

Highpass filter lowpass filter
Psophometric filter external filter
Notch filter resonance filter

Highpass and lowpass filters can be combined independently into four different filter configurations.

The psophometric filter and the external filter cannot be combined, the same applies to the notch filter and the resonance filter. Since the notch filter is used for distortion and SINAD measurements, the last filter group cannot be used for evaluation during a distortion or SINAD measurement.

Notch filter and resonance filter are also being switched off when quitting or selecting a new RX-test and TX-test, since in this case SINAD or DIST measurements automatically continue to run.

Fig. 2.4-13 Signal paths

Softkey 6: IF (IF filter)

The IF filter can be switched on and off using softkey 6. The IF bandwidth is limited to approx. 25 kHz by the NARROW filter. This improves the S/N ratio, especially when receiving small RF levels, but also results in a distortion at higher deviations and/or modulation frequencies.

Softkey 7: IF-ATT (IF attenuation)

The attenuator of the IF control can be switched on or off (important with AM demodulation). Also an automatic function is available.

2.4.6 Distortion and S/N Measurements

Softkey 6 is assigned two functions:

DIST (distortion measurement) S/N (S/N measurement)

The SHIFT key is used to select between first and second function.

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DIST Function

The distortion measurement can be performed with the dimension % or dB. The test frequency may vary between 100 Hz and 4 kHz.

Dimension

The measurement is performed in dB by entering softkey 6/dimension/dB and in % by entering softkey 6/dimension/%.

Test frequency

The test frequency is defined using softkey 6/number/dimension/Hz Or kHz.

The full-scale value can also be influenced in the analog display for the distortion measurement:

The currently measured value is used to define the full-scale value by entering softkey 6/RANGE/% or dB or ENTER.

A number is used to define the full-scale value by entering Softkey 6/RANGE/number/% or dB or ENTER.

Tolerance markers can be set in the analog display using the same syntax: softkey 6/TOL/number/% or dB or ENTER.

Softkey 5: AF COUPL (test frequency)

Softkey 5 can be used to define whether the test frequency selected in the main menu under distortion is also to define the frequency of the modulation generator or not.

Application:

Generally, coupling offers advantages. The modulation generator supplies the signal to be measured by the distortion meter following the device-under-test. However, coupling is switched off if the radiotransmitter has a scrambler, and the modulation generator signal is set independently of the distortion test frequency.

Softkey 7: AVE LEVEL (averaging factors)

Softkey 7 selects four averaging factors:

1: One measurement determines the result.
The result is the average of two measurements.
3: The result is the average of three measurements.
4: The result is the average of four measurements.

Each single measurement corresponds to the average of five AD measurements.

In IEC bus mode, the single measurements are repeated after a delay time in the case of large changes in signal level.

Whereas the wanted signal is masked out by a filter in the case of a distortion measurement, it is switched off with the S/N measurement.

This measurement can also be performed in two dimensions; the dimensions are selected by entering softkey 6/dimension % or dB.

The current measured value is used to define the full-scale value in the analog display by entering softkey 6/RANGE/% or dB or ENTER.

The entered numeric value is used to define the full-scale value by entering softkey 6/RANGE/ number/% Or dB OF ENTER.

DIST Function: Submenu

The DIST function branches into one submenu, which is ouput in the display fields next to softkeys 5 and 7. Softkey 6 is assigned to the main menu.

Fig. 2.4-14 DIST submenu

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Tolerance markers can be set in the analog display by entering softkey 6/TOL/number/% or dB or ENTER.

The S/N function branches to one submenu which is output in the display fields next to softkeys 5 and 7. Softkey 6 remains assigned to the main menu.

Fig. 2.4-15 S/N submenu

Softkey 5: GEN 2 (modulation generator 2)

The wanted modulation signal is switched on and off alternately in the course of the S/N measurement. Softkey 5 is used to select whether the modulation generator 2 is to to follow this rythm or not.

Softkey 7: AVE LEVEL (averaging factors)

Softkey 7 selects four averaging factors:

1: The result is the average of one signal measurement and two noise measurements.
2: The result is the average of one signal measurement and three noise measurements.
3: The result is the average of two signal measurements and four noise measurements.
4: The result is the average of two signal measurements and five noise measurements.

Each single measurement corresponds to the average of five AD measurements.

In manual operation and IEC bus mode, the single measurements are repeated after a delay time in the case of large changes in signal level. (Different S/N ratios (measurement times) may be the result).

2.4.7 Input Switchover

INPUT 1/INPUT 2 Function

The selected RF input (RF IN/OUT or RF 2) is shown in inverted form. The other input can be selected by entering SHIFT/ softkey 7. It is possible to inform the CMS of the attenuation value connected prior to the associated input. By entering softkey 7/number/dB or ENTER the CMS takes into account the entered attenuation for the level with RF measurement and setting.

2.4.8 Lock

LOCK Function

Softkey 8 is assigned a simple changeover key function.

If the LOCK mode is active, TX test can only be reached by operation in the RX test. With the LOCK function deactivated the switchover from RX test to TX test is only possible by applying an RF power to the RF IN/OUT socket 29 . The RX test is automatically activated again by an RF voltage drop. This return to RX test can, however, be eliminated when switching over to the TX test via keys or by calling a submenu in the TX test.

Application:

The LOCK status is used if discontinuous transmitter tests are performed, e.g. power pulses of limited duration with superimposed modulated data messages. The LOCK function prevents the CMS from returning to the receiver test following each pulse. A typical example is an acknowledge call. The LOCK function is automatically switched on in this case and with certain other measurements such as e.g. cellular radio.

2.4.9 Modulation Generators

Softkey 9 is assigned all functions of the first modulation generator, softkey 10 those of the second modulation generator. The frequency is the first function and the level of the modulation generator is the second. Switching between the two functions is possible by entering SHIFT/softkey 9 or 10.

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AF 1/AF2 Function

The frequency is entered using softkey 9 or 10/number/dimension or ENTER. The modulation generator is switched off by entering softkey 9 or 10/0FF. This switch-off function for the level with a frequency entry has the following purpose:

The levels of tone sequences generated naturally by modulation generators are set using the level function. If the modulation generator is not switched off using the above-mentioned method, the valid continuous tone is output before and after the tone sequence. The modulation generator can be switched on again using softkey 9 or 10/0N.

Variation function

The variation increment for the VAR spinwheel can be entered using softkey 9 or 10/VAR/number/ dimension or ENTER. In contrast to usual operation, VAR/0/ENTER does not set the minimum increment but leads to variation with the fixed frequency series (see VAR function, Section 2.3.2.2.1 and definition menu for tones, Section 2.8).

Reference function

The selected frequency is defined to be the reference by entering REF/number/dimension or ENTER. The set frequencies must be understood as a difference from the reference frequency (see REF function, Section 2.3.2.2.1).

LEV1/LEV2 Function

Since the source impedance of the modulation generator is very low, the set level is to be understood as the EMF.

The modulation generator level is entered using softkey 9 or 10/number/dimension or ENTER. The power is referred to 600 Ω when the dimension dBm is selected. The level is switched off using softkey 9 or 10/0FF, and the previously valid level is switched on again using softkey 9 or 10/0N (a special method for switching off the level is described with the AF1/AF2 function). Calling the beat frequency measurement automatically switches off the two modulation generators.

Variation function

The variation increment on the VAR spinwheel can be set using softkey 9 or 10/VAR/number/ dimension Or ENTER.

Application:

The modulation signal must be increased by 20 dB in the case of certain measurements. It is recommendable to enter softkey 9 or 10/VAR/20/dB in this case. One step on the VAR spinwheel switches the 20-dB overload on and off independent of the selected level.

Reference function

The variation increment for the level on the VAR spinwheel can be set using softkey 9 or 10/REF/number/dimension or ENTER.

2.4.10 Oscilloscope / DC Measurement

The scope mode is activated by means of the softkey SCOPE MODE. If the active cursor is located at this position, a submenu may be called for handling the signal sources for the scope and activating the DC measurement.

If the active cursor is located at this position, it can also mean when entering

<CLEAR> : Switching on the FREEZE mode. Signal recording is stopped. "FREEZE" appears in the display.
<ENTER>: Switching off the FREEZE mode. Signal recording continues.

Quitting the current main menu leads to deactivation of the FREEZE mode.

SCOPE MODE Function

Softkey 12: BEST RANGE

The automatic amplitude scaling can be switched on and off using this softkey. With the automatic amplitude setting switched on, the best gain (filling the complete format) is set in steps of 1-2-5. The associated scale is displayed on the scope screen.

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Softkey 13: AMP (amplitude setting)

With softkey 13 activated (active cursor), the gain setting can be selected manually in steps of 1-2-5 using the VAR spinwheel.

Softkey 14: TIME (time scaling)

If softkey 14 is activated, the time scale can be varied using the VAR spinwheel in steps of 1-2-5.

Softkey 15: Y POS (Y-position)

Activating softkey 15 allows for shifting the position of the displayed signal in the vertical direction using the VAR spinwheel.

The SCOPE MODE function has a submenu which is displayed in the fields next to softkeys 11 to 15.

Fig. 2.4-16 SCOPE MODE submenu

Softkey 11: SOURCE AUTO (automatic signal source selection)

If softkey 11 is used to switch on the automatic source selection, the demodulated signal is automatically displayed in the transmitter test and the signal at the AF/SCOPE connector in the receiver test.

Softkey 12: SOURCE FIX (Manual selection of signal source)

AF: AF signal at AF/SCOPE connector

DEMOD/BEAT: Selection of demodulated signal or beat signal. The beat signal is displayed on the scope screen.

MOD EXT: Modulation input for external signals.

DIST

When this softkey is activated, the signal path SOURCE DIST shown in Fig. 2.4-17 will be applied to the sope.

Fig. 2.4-17 Signal paths

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2.5 Receiver Test (RX-Test)

Fig. 2.5-1 Main menu RX-Test

Starting with the main menus of the selection menu, the main menu RX-TEST (receiver test) can be reached by pressing the softkey RX-TEST.

It contains all controls required to carry out a standard receiver test. Almost every function contains submenus. These contain controls which can be used for more seldom receiver test functions.

Softkey 0 can be used to directly branch to the main menu for the transmitter test (TX-TEST).

2.5.1 RF Setting

SET RF Function

The signal generator frequency of the instrument can be set using the SET RF function. This function is entered by means of sequence SET RF/number/dimension OF ENTER.

The signal generator frequency setting can be varied using the VAR function and the VAR spinwheel.

The signal generator frequency setting can also be made in relative mode.

The reference frequency is entered using softkey SET/REF/ENTER, if the current frequency is to become the reference frequency, or using softkey SET REF/number/dimension or ENTER if another frequency is to be set as the reference frequency.

SET RF Function: Submenu

The SET RF function has a submenu which is output in the display fields next to softkeys 3 to 7.

Fig. 2.5-2 SET RF submenu

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Softkey 3: FRQ TRANS

(Frequency transfer function)

Actuating this softkey switches the frequency transfer function on or off.

An activated transfer function has the following effects:

At the point of switchover from TX→RX, the RX RF frequency is calculated from the RF frequency set or counted in the TX test and the duplex spacing.
At the point of switchover from RX→TX, the TX RF frequency is calculated from the RF frequency set in the RX test and the duplex spacing, if the RF counter in the TX test is off.
When the RX RF frequency in the duplex menu is changed, the TX RF frequency continuously follows displaced by the duplex spacing, if the RF counter is off.
When the TX RF frequency is changed (by RF counter or setting), the RX RF frequency follows displaced by the duplex spacing.

Softkey 4: DUPLEX SPACE

The duplex spacing is entered by sequence sign/ number/(dimension or ENTER).

Values between -500MHz and + 500MHz are possible.

The duplex spacing is positively counted if the RX RF frequency is larger than the TX RF frequency.

Softkeys 5, 6 and 7 serve to define the channel numbers.

Softkey 5: REF-CHANNEL (Reference channel)

The reference channel is entered by number/ ENTER.

Values between 0 and 9999 are possible.

Entries are permissible only if the channel number mode is off (softkey 7).

This entry establishes reference between frequencies and channel numbers. In addition to the reference channel entry, also the respective reference frequency is displayed.

At a duplex spacing not equal to zero, the reference frequency in the TX and RX test is different. In the DX test, the reference frequency is always referred to the RX frequency.

Softkey 6: CH-SPACE (Defining of channel spacing)

The channel spacing is entered by sequence sign/ number/(dimension Or ENTER).

Values between -1MHz and + 1MHz are possible. Entries are permissible only if the channel number mode is off (softkey 7).

A positive sign means that higher channel numbers correspond to higher frequencies.

Softkey 7: CH NUMB. (Channel number)

Actuating softkey 7 switches the channel number mode on or off.

When channel number mode is on, frequencies are only displayed as channel numbers plus offset. Reference between channel numbers and frequencies is made when the reference channel is entered.

If the channel number mode is activated for the TX test, the TX RF frequency is assigned to the reference channel selected by softkey 5.

With VAR spinwheel variations, the frequencies are also varied in the channel number mode. This gives the offset to the channel number.

Offset also occurs if the RF counter counts frequencies that are not exactly in line with the channel spacing.

Frequencies with channel numbers below 0 or above 9999 are not indicated as channel number plus offset, but by normal frequency display.

840.0009.33

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2.5.2 RF Level Setting

RF LEV Function

The signal generator level can be set using the RF LEV function. The entry is made using softkey 2/number/dimension or ENTER. If a number is not entered, this sequence can be used to convert the dimension of the set level.

The RF level can be switched off temporarily using softkey 2/0FF. The previously valid level can be switched on again using softkey 2/0N.

Whereas directly entering parameters or varying parameters using the VAR spinwheel are simply different methods of operation which lead to the same result, adjustment of the RF level using keys or the VAR spinwheel leads to different results.

The interrupt-free electronic level fine variation is used for varying the level to smaller values by means of the VAR spinwheel. The level can be reduced interruption-free by 19.9 dB in FM and $\phiM$ modes, and by 4.9 dB in AM mode. The range used by the electronic level fine variation for the reduction in level is indicated in the analog display (in the field next to softkey 2) by a marker leading from right to left. On the other hand, setting the level using the digital keypad mainly uses the mechanical attenuators (audible switching).

Note:

Frequent level variations in automatic test systems might reduce the life utility of the attenuator. It is therefore recommended to carry out the level settings in few steps only, using the electronic level variation if possible.

Application:

The interrupt-free electronic level fine variation is used to search for the squelch point and the squelch hysteresis of the radio receiver. On the other hand, entering the level on the digital keypad always results in the optimum broadband S/N ratio of the CMS signal generator, increased level accuracy and a reduced AM distortion factor.

The variation increment can be set using softkey SET RF/VAR/number/dimension or ENTER (see function-based hardkeys (VAR), Section 2.3.2.2.1 and spinwheel, Section 2.3.2.3).

The signal generator level setting can also be made in relative mode. The reference level can be entered using softkey SET/REF/ENTER if the current level is to become the reference level, or using softkey SET/REF/number/dimension or ENTER if a different level is to be set as the reference level.

RF LEV Function: Submenu

The RF LEV function has a very important submenu which contains the automatic test routines of the receiver test. The RF LEV submenu is output in the display fields next to softkeys 3 to 5 and 7.

It is important with the automatic test routines to ensure that the radiotelephone is completely connected to the CMS. The connectors RF IN/OUT and AF/SCOPE are used for this purpose.

Since the automatic test routines may require a lengthy period of time, they can be aborted during the measurement by pressing the RF/LEV softkey.

Fig. 2.5-3 RF LEV submenu

Softkey 3: BNDWTH MEAS (bandwidth measurement)

Softkey 3 starts the bandwidth measurement.

The measurement is run as follows:

Initial setting: RF frequency = nominal receiver center frequency. The receiver squelch is switched off.
2. Definition of the AF noise level with RF level switched off.
Increase in RF level until the AF noise level has decreased by 10 dB. Storage of AF noise level.
4. Increase in RF level by further 6 dB.

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Offset of RF frequency to higher frequencies until the AF noise level of point 3 is obtained again.
6. Offset of RF frequency to lower frequencies until the AF noise level of point 3 is obtained again.
The receiver band limits defined under points and 6 serve for determining the receive bandwidth and the center frequency offset. These two values are displayed.

Softkey 4: SQUELCH MEAS (squelch measurement)

Softkey 4 starts the squelch measurement.

The measurement is run as follows:

1. Initial setting: The RF level is set to the minimal value. The receiver squelch is switched on.
2. The RF level is increased interrupt-free until the AF level is switched on on the radiotelephone. This is the squelch switch-off point.
3. The RF level is decreased until the AF level on the radiotelephone is switched off again. The squelch hysteresis is the difference between the two RF levels.
4. Squelch inset and squelch hysteresis are displayed.

Softkey 5: QUIET

(quieting measurement)

The quieting measurement is initiated via Softkey 5/number/dimension dB or ENTER. The number in dB corresponds to the quieting criterion.

The measurement is run as follows:

1. Initial setting: RF frequency = receiver center frequency. RF level = off. The receiver squelch is switched off.
2. The AF noise level is measured.
3. The RF level is increased until the AF noise level has decreased by the number specified as the quieting criterion.
4. This RF level is displayed as result.

Softkey 7: LEVEL (EMF-PD switchover)

Softkey 7 can be used to select whether the output RF voltage is to be displayed as a no-load voltage (EMF) or as a terminal voltage (PD) accross a 50-Ω load.

2.5.3 AF Level Measurement

AF LEV Function

The AF level measurement is selected by pressing softkey 3. The dimension can be selected by subsequently pressing a dimension key; the dimensions mV, W, dBµV and dBm are possible. Measurements in W and dBm are usually based on a load resistance of 600 Ω. This can be changed, however, in the definition menu for special functions. (Section 2.9).

Tolerance markers can be set in the analog display using softkey 3/TOL/number/dimension Or ENTER.

The currently measured value is used to define the full-scale value on the analog display using softkey 3/RANGE/dimension or ENTER. The value corresponding to the number is used to define the full-scale value using softkey 3/RANGE/number /dimension or ENTER.

The current measured value is defined as the reference value using softkey 3/REF/dimension or ENTER, and the subsequent measurements are made in dB referred to this value. A reference value can be defined using softkey 3/REF/number/dimension or ENTER. An integer multiplier, which is then part of the AF-LEV result, can be specified using Softkey 3/number/ENTER.

AF LEV Function: Submenu

The AF LEV function has a submenu which is output in the fields in the display next to softkeys 4 to 7.

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Fig. 2.5-4 AF LEV submenu

Softkey 4: WEIGHT

Softkey 4 can be used to select four different types of weighting.

RMS: Real RMS weighting
√2 * RMS: Real RMS weighting multiplied by 1.41.

This weighting is used if the peak value is to be determined when modulating with sinewave signals, and the integrating effect of the RMS detector is to be used at the same time (e.g. with noisy signals).

+ PK: Positive peak weighting
PK: Negative peak weighting

Softkey 5: AVE LEVEL (averaging factor)

Softkey 5 can be used to select an averaging factor for RMS and $\sqrt{2} * RMS$ weighting. Four averaging possibilities are provided.

1: One measurement determines the result.
2: The result is the average of two measurements.
3: The result is the average of three measurements.
4: The result is the average of four measurements.

Each single measurement corresponds to the average of 5 AD measurements.

In IEC bus operation, the single measurements are repeated with high changes in signal level following a delay time.

Application:

A higher averaging factor results in more reproducible results compared to a single measurement especially in the case of noisy signals. An average measurement takes longer, however. The AF voltmeter is often used in the receiver test to measure the AF noise of the receiver which is not supplied with an RF signal. The reproducibility of these noise measurements is improved by averaging.

Averaging is not carried out for peak weighting.

Softkey 6: COUPL (AC/DC coupling)

Softkey 6 can be used to couple the detectors to the signal source in three different manners:

AC coupling: Only AC voltages ≥ 50 Hz are measured. DC/3Hz: Pure DC measurement. AC components above 3 Hz are
components above 3 Hz are suppressed. DC/WIDE: AC and DC components are RMS
or peak weighted together.

Softkey 7: AF ATT (input divider)

The CMS has a selectable input voltage divider in order to expand the dynamic range of the measurement points at higher values. This is usually switched on or off automatically depending on the measured value.

If the automatic feature does not meet all requirements, it can be switched off (e.g. to save time).

Selection is possible using softkey 7 between:

AUTO: Automatic adaptation to measured value
ON: A dynamic range of 24 dB is lost at small measured values.
OFF: Top limit of measuring range approx. 1.4 V.

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2.5.4 Code, Count

Softkey 4 is assigned two functions: SELCAL (SELCAL outputs) COUNT (AF frequency counting)

The first or second function is selected using the SHIFT key.

SELCAL Function

An already stored selective call can be sent to the radiotelephone via the RF path using softkey 4/ENTER.

A new call number can be entered and sent using softkey 4/number/ENTER. The digits can be 0 to 9 and A to F, and also * and # with dual-tone sequences. A sequence with up to 30 digits can be entered.

A tone sequence can be incorporated in a continuous tone of constant modulation or output as a modulation burst. Section 2.5.9 describes the setting of the two modes.

The SELCAL function has two submenus which are output in the fields in the display next to softkeys 3 to 7.

These submenus are used for the most significant configurations in conjunction with SELCAL transmissions.

Other configurations which are required less often, but then for longer periods, are set up in the "Definition menu for tones" (Section 2.8).

Softkey 3: SELCAL (selection of standard)

One of 12 standards can be selected using softkey 3/number/ENTER. A number is assigned to each standard.

Section 2.4.4 explains the meaning of the numbers in more detail.

Function SELCAL CDCSS (Standard 15)

After activating softkey SELCAL, a 3-digit octal number which has to correspond to one of the 83 CDCSS codes can be entered. Prefix # has to be put in front of the octal number for inverted codes. Acknowledgement using the ENTER key effects a cyclic transmission of the CDCSS code via modulation generator 2 whose deviation can be selected as already known.

Pressing key CLEAR effects the generation of the turn-off code and the subsequent cutting off of the RF power (cf. submenu 2).

For further explanations refer to Section 2.8.

Softkey 4: MSG REPEAT (Message Repeat)

Softkey 4/number/ENTER is used to define how often the message is to be repeated. A value of 1 corresponds to the normal setting.

Larger numbers are entered if the response sensitivity of a radiotelephone to the telegram is to be determined. The RF level is then varied whilst the telegrams are sent until the receiver responds. Uninterrupted repetition of telegrams can be stopped by pressing the OFF key.

Softkey 5: REPEAT TONE

The digit repeat function can be switched on or off using softkey 5.

With the digit repeat switched on, the second digit of a double digit is replaced by the repeat digit (E). With the digit repeat switched off, the second digit is repeated, which usually leads to an extra-long tone. The digit repeat of the decoder is coupled to this function (see Section 2.4.4).

Softkey 6: ACK TEST (acknowledgement test)

The automatic sequence "Acknowledgement call test" is started by pressing softkey 6; it is then started by activating softkey 4 SELCAL in the main menu RX-test. The sequence comprises the following steps:

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1. Transmission of previously selected tone sequence.
2. Following the last tone in the sequence, the CMS is transferred to the transmitter test with all settings belonging to this test. Note in particular that the transmitter test operating frequency must still be set in the transmitter test to the frequency at which the reply from the radiotelephone is expected. In the position + RF OFF the RF-carrier of the CMS is additionally switched off after the last tone of the tone sequence, since some radiotelephones only reply without input signal.
3. The result of the acknowledgement test is the decoded tone sequence and the modulation.

Softkey 7: FRQ DEVI (frequency deviation)

In order to carry out frequency limit tests on the selective call evaluator, a relative frequency deviation of up to ±10 % can be selected uniformly for all tones in the sequence.

This is entered using softkey 7/number with or without sign/ENTER. The number corresponds to the frequency deviation in %.

Fig. 2.5-6 SELCAL submenu 2

Softkey 3 is assigned two functions. The SHIFT key is used for selecting first or second function.

Softkey 3: NO SPEC

This function is used to select a tone of the selective-call sequence which is to be subjected to extended tone duration. This is normally the first tone of extended duration compared to the other tones. The entry is made using Softkey 3 (NO SPC)/number (tone duration in ms)/ENTER.

Softkey 3: LENGTH

Softkey 3 is assigned two functions. The SHIFT key is used for selecting first or second function. Certain selective call principles can also address receivers with sleep mode. An extended tone in the selective call sequence then bridges the "sleeping pause" of the receiver. The duration of the first tone can be set using softkey 3 LENGTH/number/ENTER and corresponds to the number in ms.

Softkey 4: OTHER LENGTH (duration of other tones)

The duration (in ms) of the following tones can be uniformly set by entering softkey 4/number/ENTER.

Softkey 5: DIGIT PAUSE

Pauses can be defined between the tones (in ms) uniformly for a tone sequence by entering soft-key/5/ number/ENTER.

The tone and pause durations need only be selected if values different from the standard are required. These values are components of the standard and can be assigned to the individual standards in the "Definition menu for tones" (Section 2.8).

Softkey 6: MSG PAUSE (message pause)

The pause (in ms) between two messages is defined by entering softkey 6/number/ENTER.

Softkey 7: RESET STD

The original parameters, modified by softkeys 3 to 6 can be reset using this softkey.

Das Untermenü 2 hat für Standard 15 (ATIA) keine Bedeutung.

Im Fall des Standard 15 hat das Untermenü 2 ein verändertes Aussehen:

CDCSS: Submenu 2

Softkey TRN-OFF-SELCAL can be used to set the length of the turn-off code effecting the turn off of the squelch function of the test object connected.

Softkey TRANSM END serves to set the time between the start of the turn-off code and the cutting off of the transmitter.

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This function is used to determine the frequency of the signal connected to the AF/SCOPE connector 24.

A reference frequency can be entered using softkey 4/REF/number/dimension or ENTER and is always subtracted from the absolute counter result. The currently measured frequency is set as the reference frequency using softkey 4/REF/dimension or ENTER.

COUNT Function: Submenu

The COUNT function has a submenu which is output in the display field next to softkey 5.

Fig. 2.5-9 COUNT submenu

Softkey 5: MODE (operating mode and resolution of counter)

Selection between 2 modes is possible:

Period counting Gate time counting 1 Hz

Period counting has a resolution of 0.1 Hz up to 100 kHz; the resolution is 1 Hz at frequencies exceeding this value. Period counting is fast but requires a signal without noise.

Gate time counting is less sensitive to noisy signals.

2.5.5 Filter Selection

Various AF filters can be switched on or off using softkey 5/0N or OFF. The AF filters and their characteristic frequencies can be selected in two submenus.

The FILTER function has two submenus. The first submenu is output in the display fields next to softkeys 4 and 7, the second submenu in the fields next to softkeys 4 to 5.

Die Bedienung der Softkeys 4 bis 7 ist analog zur Betriebsart Sendertest im Kapitel 2.4.5.

The FILTER submenu 2 is called by pressing the MENU ↓ (DOWN) key.

FILTER Function: Submenu 2

Die Bedienung der Softkeys 4 & 5 ist analog denen der Betriebsart Sendertest und ist bereits in 2.4.5 beschrieben worden. Softkeys 6 & 7 werden jedoch nicht angezeigt.

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2.5.6 SINAD and Distortion Measurements

Softkey 6 is assigned two functions:

SINAD	(S/N measurement)
DIST	(distortion measurement)

The SHIFT key is used to select either the first or second function.

SINAD/DIST Function

Both measurements are performed using the same method. The result is displayed in dB for SINAD and in % for distortion.

Test frequency

The test frequency is defined via softkey 6/ number/dimension Hz or kHz. It is possible to select in the submenu whether the modulation generator is to be set to this frequency or not.

Automatic search routine

The automatic search routine is started using softkey 6/number/dimension % (distortion) or dB (SINAD). The routine is run as follows:

The RF level is modified until the measured value corresponding to the number is reached. The RF level obtained at the end of the search routine corresponds to the receiver sensitivity. The search routine can be aborted by pressing softkey 6.

The full-scale value can also be influenced in the analog display for the SINAD or DIST measurement.

When softkey 6/RANGE/% or dB or ENTER are pressed, the currently measured value is used for defining the full-scale value.

When softkey 6/RANGE/number/% or dB or ENTER are pressed, the entered number is used for defining the full-scale value.

Tolerance markers can be set in the analog display using the same syntax: softkey 6/TOL/ number/% or dB or ENTER.

SINAD/ DIST Function: Submenu

A submenu is available for the SINAD/DIST function, which is output in the display fields next to softkeys 3 to 5 and 7. Softkey 6 remains assigned to the main menu.

Fig. 2.5-10 SINAD/DIST submenu

Softkey 3: AF COUPL (test frequency)

Softkey 3 can be used to define whether the test frequency selected for the distortion is also to define the frequency of the modulation generator 1 or not.

Application:

Coupling usually has advantages. The modulation generator supplies the signal, which is to be measured by the distortion meter or the SINAD meter following the device-under-test. However, if the radio receiver has a scrambler, the coupling is switched off and the modulation generator signal is set independently of the distortion/SINAD test frequency.

Softkey 4: WINDOW (abort window)

Softkey 4 can be used to define a criterion for aborting the automatic search routine. The range around the target value to be measured is determined by entering softkey 4/number/dB or %.The entered number defines the magnitude in % or dB around the target value as the abort window. When a measured value from this range is reached in the search routine for the first time, the search routine is aborted.

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Softkey 5: LEVEL SEARCH

(Stop/continue search routine)

Softkey 5 selects whether the RF level variation is to be stopped when the abort window is reached or not.

Application:

If the receiver sensitivity is to be determined by a measurement, the "stop" position is selected. The "continue" position is selected if the receiver sensitivity is to be set to a maximum during the search routine.

Softkey 7: AVE LEVEL (averaging factors)

Four averaging factors are available to be selected via softkey 7.

1: One measurement determines the result.
2: The result is the average of two measurements.
3: The result is the average of three measurements.
4: The result is the average of four measurements.

Each single measurement corresponds to the average of 5 AD values.

In IEC bus operation, the single measurements are repeated with large changes in signal level following a delay time.

2.5.7 S/N Measurement

S/N Function

The S/N measurement is very similar to the distortion or SINAD measurement except that the wanted modulation is switched off during the noise measurement and not eliminated by a filter.

Dimension

The S/N ratio is displayed either in % or dB by entering softkey 7/dimension % or dB.

The full-scale value can also be influenced in the analog display for the S/Nmeasurement.

The currently measured value is used to define the full-scale value by entering softkey 7/RANGE/%/ or dB or ENTER.

The number is used to define the full-scale value by entering softkey 7/RANGE/number/%/ or dB or ENTER.

Tolerance markers can be set in the analog display with the same syntax: softkey 7/TOL/ number/% Or dB Or ENTER.

Automatic search routine

An automatic search routine is initated via softkey 7/number/dimension % or dB. The routine is executed as follows:

The RF level is modified until the measured value corresponding to the number is reached. The RF level at the end of the search routine corresponds to the receiver sensitivity.

The search routine can be aborted by pressing softkey 7.

A submenu is available for the S/N function, which is output in the display fileds next to softkeys 3 to 7.

Fig. 2.5-11 S/N submenu

Softkey 3: GEN 2 (modulation generator 2)

The modulation is switched on and off by modulation generator 1. Softkey 3 can be used to select whether the modulation generator 2 is to follow this rythm or not.

Softkey 4: EXT (external modulation)

Softkey 4 can be used in the same manner as described above to select whether the external modulation applied to the MOD EXT connector 26 is to follow this rythm or not.

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Softkey 5: WINDOW (abort window)

Softkey 5 can be used to define a criterion for aborting the automatic search routine. The range around the target value to be measured is determined by entering softkey 5/number/dB or %. The entered number determines the magnitude in % or dB around the target value as the abort window. When a measured value from this range is reached in the search routine for the first time, the search routine is aborted.

Softkey 6: LEVEL SEARCH (stop/continue search routine)

Softkey 6 selects whether the RF level variation is to be stopped when the abort window is reached or not.

Application:

Softkey 7: AVE LEVEL (averaging factors)

Four averaging factors can be selected using softkey 7:

1: The result is the average of one signal measurement and two noise measurements.
2: The result is the average of one signal measurement and three noise measurements.
3: The result is the average of two signal measurements and four noise measurements.
4: The result is the average of two signal measurements and five noise measurements.

Each single measurement corresponds to the average of five AD measurements.

In local and IEC bus mode, the single measurements are repeated following a delay time in case of large changes in signal level. (Different S/N ratios (measurement times) may result.)

2.5.8 Lock

LOCK Function

Softkey 8 is assigned the function of a simple changeover key.

If the LOCK mode is active, TX test can only be reached by operation in the RX test. With the LOCK function deactivated the switchover from RX test to TX test is only possible by applying an RF power to the RF IN/OUT socket 29 . The RX test is automatically actuated again by an RF voltage drop. This return to RX test can, however, be eliminated when switching to the TX test via keys or by calling a submenu in the TX test.

Application:

The LOCK status is used if discontinuous transmitter tests are carried out, e.g. power pulses of limited duration with superimposed modulated data messages. The LOCK function prevents the CMS from returning to the receiver test following each pulse. A typical example is a acknowledgement call. The LOCK function is switched on automatically in this case and with certain other measurements such as e.g. cellular radio.

2.5.9 Modulation Generators

Softkey 9 is assigned all functions of the first modulation generator, softkey 10 those of the second modulation generator. Each softkey is assigned the frequency as first function and the modulation as the second. Switching between the two functions is possible by entering SHIFT/softkey 9 or 10.


AF1/AF2 Function

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The modulation of tone sequences generated naturally by modulation generators are set using the MOD function. If the modulation generator is not switched off using the above-mentioned method, the valid continuous tone is output before and after the tone sequence. The modulation generator can be switched on again using softkey 9 or 10/0N.

Variation function

The variation increment for the VAR spinwheel can be entered using softkey 9 or 10/VAR/number/dimension or ENTER. In contrast to usual operation, VAR/0/ENTER does not set the minimum increment but leads to variation with the fixed frequency series (see VAR function, Section 2.3.2.2.1 and definition menu for tones, Section 2.8).

Reference function

The selected frequency is defined to be the reference by entering REF/number/dimension or ENTER. The set frequencies are to be understood as a difference from the reference frequency (see REF function, Section 2.3.2.2.1).

MOD1/MOD2 Function

The modulation is entered using softkey 9/number/dimension or ENTER. The operating mode of the instrument is determined by the dimension selected for the 1st modulation generator.

Selection of the dimension % sets the CMS to AM mode, selection of the dimension kHz or Hz to FM mode and selection of the dimension rad to $\phiM$ mode.

The modulation mode of the 2nd modulation generator follows that of the 1st (dual-tone modulation).

(An external modulation source is used for dualtone modulation.)

The modulation can be switched off using softkey 9 or 10/0FF, and the previously valid modulation can be switched on again using softkey 9 or 10/0N.

There is a submenu for the MOD1/MOD2 function which is output in the fields in the display next to softkeys 11 to 14. This submenu can be selected by means of softkey 9 or softkey 10.

Fig. 2.5-12 MOD1/MOD2 submenu

Softkey 11: MOD EXT (external modulation)

An external modulation signal can be connected to the MOD EXT connector and can be entered using softkey 11/number/dimension or ENTER. Modulation mode AM (multi-tone) is possible via the external input if the instrument is in AM mode. The dimensions used are %, kHz or Hz.

Further FM modulation (multi-tone) is possible via the external input if the instrument is in FM mode.

Softkey 12: MOD OFF (switching off modulation)

All modulation is switched off by pressing softkey 12; the modulation modes are retained.

Softkey 13: MOD EXT CAL (external calibration)

Softkey 13 should be pressed if the voltage applied to the MOD EXT connector is unknown. The instrument then measures this voltage (output in the display) and takes it into account when setting the modulation. (Subsequent changes in voltage are not taken into account.)

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Softkey 14:

MOD EXT REF (input of modulation voltage)

Softkey 14/number/dimension or ENTER can be used to inform the instrument of the voltage applied to the MOD EXT connector which is to be used as the basis for the external modulation setting. The number corresponds to the peak voltage; input ranges between 50 mV and 2 V with dc coupling and between 5 mV and 2 V with ac coupling can be taken into account, otherwise a message is output in the display.

Softkey 15: AM-COUPL

This softkey is used to select AC or DC coupling with external AM modulation.

DC coupling is selected when the RF signal amplitude is to be varied using an external DC voltage, e.g. for simulation of a fading signal.

2.5.10 Oscilloscope / DC Measurement

Operation and use of the oscilloscope and the DC measurement feature are analogous to that as described in Section 2.4.10 for the transmitter test.

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Fig. 2.6-1 Main menu TX-SSB

Starting with the main SSB mens accessible from the selection menu, the main menu TX-SSB (transmitter test) can be entered by pressing the softkey SSB. In SSB mode the CMS is switched to. Beat mode and AM modulation permanently.

This menu contains all controls required to carry out a single side band transmitter test. Almost every function offers submenus. These provide controls for additional transmitter test functions that are required less often.

Softkey 0 may be used to branch to the receiver test (RX-SSB) main menu.

2.6.1 RF Count Measurement

By simple transmitter tests (only one RF frequency present), the instrument will show the frequency of the suppressed carrier. If the device under test outputs several strong rf frequencies, the receiver frequency should be preset by toggling to SET RF.

COUNT Function

The count function is constantly active if the COUNT field is shown in inverted form.

The normal count function only operates at the connector RF IN/OUT.

The count measurement is executed in BEAT mode only.

The carrier frequency value shown depends on

the measured rf frequency
the value of the chosen AF frequency and
the setting of the ssb mode toggle (LSB, USB, CW).

In case of LSB and USB a suppressed carrier is assumed. Depending on the operating mode the following formulas apply:

LSB (lower side band): F_sc = F_m + F_af

USB (upper side band): F_sc = F_m - F_af

CW (continuous wave): F_c = F_m

with F_sc, F_c being the value of the (suppressed) carrier, Fm the measured rf frequency. Faf represents the setting of either AF1 or AF2 (please refer to description of softkey 9 or 10 for further details). In case AF1 and 2 are active simultaneously, a warning is issued; the value for Faf will correspond to AF1 in that case.

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The local oscillator is set to Fsc in case of LSB and USB. In continuous wave mode, however, the LO frequency is as follows:

F_lo = F_m - ITF

where ITF is the international telegraph standard frequency of 800 Hz.

The counter resolution can be set using the following input sequence: softkey COUNT/number 1 to 10/terminating key Hz or ENTER. Thus 1 Hz (slow) or 10 Hz (fast) is selected as the counter resolution.

Relative counting

There are two possibilities for selecting a reference frequency for relative counting.

Input of softkey COUNT/REF/ENTER declares the frequency just measured as the reference frequency; input of softkey COUNT /REF /number /unit key or ENTER declares the entered frequency; as the reference frequency.

A sign in front of the result indicates that a relative frequency count is being carried out. Absolute frequency counting can be reselected by entering softkey COUNT/REF/OFF.

The dimensions MHz, kHz or Hz can be selected for direct or relative counting, e.g. softkey COUNT/Hz.

COUNT Function: Submenu

The function COUNT has a submenu which is output in the display fields next to softkeys 3, 4 and 5.

Fig. 2.6-2 COUNT submenu

The normal count function comprises a coarse direct broadband count and a subsequent exact AF count.

Softkey 3: FRQ PRESET (IF count)

This setting is of no consequence in SSB mode, since the IF section is not employed with BEAT demodulation.

Softkey 4: DIRECT COUNT

Switch-on: Softkey 4/number 100 or 1000/ dimension Hz or ENTER. Direct counting is carried out with a resolution of 100 or 1000 Hz.

Switch-off: Softkey 4/0FF

Softkey 5: FRQ TRANS (Transfer function)

Actuating this softkey once transfers the measured frequency as CMS receiver frequency.

In the main menu, this action switches from the COUNT function to SET RF.

Application:

Softkey 5 facilitates operation with regard to entry of multi-digit or unknown trans-mitter frequencies as CMS receiver frequency.

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SET RF Function

The receiver frequency setting can be varied using the VAR function and the VAR spinwheel. The receiver frequency setting can also be relative.

The reference frequency can be entered using sofkey SET RF/REF/ENTER if the current frequency is to become the reference frequency, or using the softkey SET RF/REF/number/dimension or ENTER if a reference frequency is to be set to a different value.

SET RF Function: Submenu

This submenu has been described in the TX-Test section of this manual. Please refer to section 2.4.

2.6.2 Power Measurement

POWER Function

A logarithmic relative display based on a reference value may be selected. Tolerance markers can be set on the analog bar for the dimensions mentioned above; Autorange or Range Hold for the full-scale value can be selected on the analog display.

POWER Function: Submenu

This submenu has been described in the TX-Test section of this manual. Please refer to section 2.4.

2.6.3 MODE Function

MODE Function

The DUT's SSB transmission mode is set using softkey 3. Three different settings may be selected:

LSB (Lower Side Band)

USB (Upper Side Band)

CW (Continuous Wave).

In order to correctly measure the frequeny of the suppressed carrier, it is necessary to supply the SSB transmission mode employed.

2.6.4 AF Measurement

Please see 2.4 for information on the decode function.

COUNT Function

The frequency of the demodulated signal or the beat signal is counted by pressing softkey 4.

A relative measurement can be made in two different manners:

The currently measured frequency is selected as the reference frequency by entering softkey 4/REF/ENTER.
An arbitrary frequency value is selected as the reference frequency by entering REF/number/dimension or ENTER.

The relative result is the difference to the reference frequency. Relative measurements are identified by a sign in front of the result.

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FILTER Function: Submenu 2

The COUNT function has a submenu which is output in the field of the display next to softkey 6.

COUNT Function: Submenu

Fig.2.6-3 COUNT submenu

Softkey 6: MODE (Operating mode and resolution of counter)

There are two alternatives:

Period counting
Gate time counting

Period counting has a resolution of 0.1 Hz up to 100 kHz; the resolution is 1 Hz at frequencies above this value. Period counting is fast but requires a signal without noise.

Gate time counting is slower but less sensitive to noisy signals.

2.6.5 Filter Selection

Various AF filters can be switched on or off using softkey 5/0N or 0FF. The AF filters and their characteristic frequencies can be selected in two submenus.

This submenu has been described in the TX-Test section of this manual. Please refer to section 2.4.

Fig. 2.6-4 FILTER submenu 2

Softkey 4: NOTCH (notch filter)

The notch filter is switched on using softkey 4/0N and off using softkey 4/0FF.

Stop frequency of notch filter:

The stop frequency of the notch filter is also selected using softkey 4. The entry is made using softkey 4/number/dimension or ENTER.

Since the frequencies cannot always be set exactly as required, the frequency actually set is output in the display.

Softkey 5: RESON (resonance filter)

The resonance filter is switched on using softkey 5/0N and off using softkey 5/0FF.

Resonance frequency of resonance filter: Softkey 5 is used to select the resonance frequency of the filter. The entry is made using softkey 5/number/dimension or ENTER. The actually set frequency is displayed as with the notch filter.

Filter combinations

For better understanding all filters can be envisaged as a series connection of three filter groups:

Highpass filter lowpass filter
Psophometric filter external filter
Notch filter resonance filter

Highpass and lowpass filters can be combined independently into four different filter configurations.

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Notch filter and resonance filter are also being switched off when quitting or selecting RX-test and TX-test, since in this case SINAD or DIST measurements automatically continue to run.

Fig. 2.6-5 Signal paths

Distortion Measurement

This funciton has been described in the TX-Test section of this manual. Please refer to section 2.4.

Input Switchover

This function has been described in the TX-Test section of this manual. Please refer to section 2.4.

Lock

This function has been described in the TX-Test section of this manual. Please refer to section 2.4.

Modulation Generators

This function has been described in the TX-Test section of this manual. Please refer to section 2.4.

Oscilloscope / DC Measurement

SCOPE MODE Function

This function has been described in the TX-Test section of this manual. Please refer to section 2.4.

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2.7 SSB-Receiver Test (RX-SSB)

Fig. 2.7-1 Main menu RX-SSB

The main menu RX-SSB (receiver test) can be accessed by pressing the softkey RX-SSB in the upper left corner of the SSB transmitter test menu TX-SSB.

It contains all controls required to carry out a single side band receiver test. Almost every function contains submenus. These contain controls which can be used for more seldom receiver test functions.

Softkey 0 may be used to branch to the main menu for the transmitter test (TX-5SB).

Notes on modulation in SSB mode:

In SSB mode, single or two-tone modulation is permissible. The kind of modulation depends on the number of AF generators used. To swith off an AF-Gen, depress the OFF key after selecting the frequency of either AF1 or AF2.

Input of LEV1/OFF or LEV2/OFF has no influence on single/two-tone modulation.

a) Single tone

In case modulation is supplied by a single tone, complete carrier and residual side band suppression is employed.

Fig. 2.7-2

Example:

USB-Mode (Upper Side Band): Complete absence of carrier Fc and residual side band Fc-Fs (lower side band in this example).

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b) Two-tone

In case of two-tone modulation, CMS will not suppress the spurious spectral components. Instead, the carrier as well as the modulation signals will be offset by 10 kHz, respectively. As a result, unwanted spectral components will come to rest in a position further away from the side band under analysis and thus not influence measurement results.

Fig 2.7-3 Spectral components of an unmodified AM-signal

Fig. 2.7-4 Spectral components of the modified AM-signal

Example: Mode USB, modified AM-signal

$F'c = Fc - 10kHz$ $F's = Fs + 10kHz$

By simultaneous modifiation of the carrier's and unwanted side band's frequency, the wanted side band's frequency (USB in above example) remains unaffected while the possibly disturbing components are moved out of harm's way.

Note: Since the frequency offset of both carrier and unwanted side band is achieved through the AF-Gen, the upper frequency limit of AF1 and AF2 is lowered to 20kHz. For the same reason, the frequency output at the MOD GEN socket is 10 kHz higher then displayed.

2.7.1 RF Setting

Please refer to corresponding section 2.5 (RX-Test).

2.7.2 Mode Function

MODE Function

The DUT's SSB transmission mode is set using softkey 3.

Three different settings may be selected:

LSB (Lower Side Band)
USB (Upper Side Band)
CW (Continuous Wave).

With settings LSB and USB carrier and residual side band will either not appear or be shifted into a more distant frequency range depending on type of modulation (single or two-tone).

In CW mode, the carrier that is typically suppressed in SSB will be transmitted; this carrier is defined by the frequency value supplied by the SET RF function and the RF level displayed next to softkey LEV1.

Both AF generators are switched off in CW mode, entry of AF frequency values is not possible.

2.7.3 AF Level Measurement

AF LEV Function

Please refer to corresponding section 2.5 (RX-Test).

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2.7.4 AF Count Measurement

This function has been described in the RX-Test section of this manual. Please refer to section 2.4.

2.7.5 Filter Selection

Please refer to corresponding section 2.4 (RX-Test).

2.7.6 SINAD and Distortion Measurements

SINAD/DIST Funktion

Please refer to corresponding section 2.4 (RX-Test).

2.7.7 Code

An already stored selective call can be sent to the radiotelephone via the RF path using softkey 7/ENTER. On entry into the SSB-RX menu code standard 13 with be pre-selected.

A new call number can be entered and sent using softkey 7/number/ENTER. The digits can be 0 to 9 and A to F, and also * and # with dual-tone sequences. A sequence with up to 30 digits can be entered. Depending on the tone standard selected, tone sequences of differing length may be issned; the keypad may assume different meanings (see RX-Test function CODE and ATIS/CDCSS supplement).

A tone sequence can be incorporated in a continuous tone of constant modulation or output as a modulation burst. Section 2.5.9 describes the setting of the two modes.

Code Function: Submenu 1

Please refer to corresponding section 2.4 (RX-Test).

CODE Function: Submenu 2

This functionhas been described in the RX-Test section of this manual. Please refer to section 2.4.

2.7.8 Lock

	***********************************

🛛 LO	CK Function

		00000000

This function has been described in the RX-Test section of this manual. Please refer to section 2.4.

2.7.9 Modulation Generators

Softkey 9 is assigned all functions of the first modulation generator, softkey 10 those of the second modulation generator. Each softkey is assigned the frequency as first function and RF Level as the second. Switching between the two functions is possible by entering SHIFT/softkey 9 or 10.


AE1/AE2 Eunction
AFI/AFZ FUNCTION

The frequency is entered using softkey 9 or 10/number/dimension or ENTER. The modulation generator is switched off by entering softkey 9 or 10/OFF. The modulation generator can be switched on again using softkey 9 or 10/ON.

Variation function

The variation increment for the VAR spinwheel can be entered using softkey 9 or 10/VAR/number/dimension or ENTER. In contrast to usual operation, VAR/0/ENTER does not set the minimum increment but leads to variation with the fixed frequency series (see VAR function, Section 2.3.2.2.1 and definition menu for tones, Section 2.8).

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Reference function

LEV1/LEV2 Function

Input of rf levels (determined by build-in modgen) may be accomplished through softkeys 9 or 10/number/unit or ENTER. If unit dBm is selected, power refers to 50 Ohms PD. Using softkey 9 or 10 followed by OFF will switch off the rf output attributed to LEV1 or LEV2, respectively. Softkey 9 or 10/ON switches on the level set previously (a method to switch on or off rf level and change between single and two-tone modulation as well is described with function AF1 and AF2).

Variation function

Please refer to corresponding section 2.5 (RX-Test).

Reference function

Please refer to corresponding section 2.5 (RX-Test).

2.7.10 Oscilloscope / DC Measurement

Operation and use of the oscilloscope and the DC measurement feature are analogous to that as described in Section 2.4.10 for the transmitter test.

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2.8 RF Spectrum Analyzer

RX-TEST	S	SPEC	T	CMS -	Local				TX-TEST
RF ATT	EX	T-ATT: O	.00 dB	RF-A1	T: 20.0	)0 dB	REF-LEV	∷ +16.0 dBm	REF LEV
HUIU	45				Â
KESUL. FILTER	16 kHz		į					dB/
TRACK			ļ						QUICK
RF LEV									FREEZE
CABLE									MKR -> CF
INPUT 1 INPUT 2									MKR -> Ref lev
CENTER Start	12	23.00000	MHz	RF-OFFS	1	MHz		2.00000 MHz	SPAN Stop

Fig. 2.8-1 Main Menu Spectrum Analyzer

From the select menu, the main menu of the RF spectrum analyzer can be selected by pressing the SPECT key.

In this menu, the CMS permits to display modulation spectra within one or a few channels as well as observe the complete frequency spectrum in the range from 10 MHz to 1 GHz with a span of 50 MHz.

The softkey RX-Test permits to branch directly into the main menu for the receiver test, softkey TX-Test into the main menu for the transmitter test.

In operating mode RF Spectrum analyzer, all RF functions of the instrument are made use of, even if the duplex synthesizer is installed. Thus no duplex operation is possible. To achieve highest sensitivity for measurements, use Input 2 with 6 kHz resolution filter and a reference level smaller than -35 dBm.

2.8.1.1 Functions of the Main Menu

Function RF Att/Auto

For measurements via the connector RF IN/OUT, the spectrum analyzer is provided with switchable input attenuator pads in the range from 0 to 112.5 dB. This input attenuation can be selected manually, or it is set automatically depending on the power measured by the power meter and on the reference level set. The set value is indicated in the upper display area.

Changing from automatic setting to manual setting and vice versa is effected by pressing softkey 1.

For measuring small voltages via the sensitive input connector RF IN 2, RF level matching is not possible. The functions RF ATT and AUTO are insignificant in this case.

Manual attenuation setting:

In the position RF ATT, the user can set the attenuation himself in the range from 0 to 112.5 dB. Since the total attenuation is obtained by series-connection of single attenuator pads of fixed attenuation, not all values can be implemented. The CMS therefore rounds the entry to the next possible value. Note that a 20-dB power attenuator pad is automatically cut in when a high RF power (approx. >13 dBm) is applied.

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Automatic attenuation setting:

In the AUTO position, the power at the connector RF IN/OUT is measured internally in the CMS prior to each build-up of the display, which permits the optimum setting of the input attenuation to be determined automatically.

Function Resolution Filter

This key is used to select the bandwidth of the resolution filter via which the frequency spectrum is weighted. The CMS provides 7 resolution filters with bandwidths from 150 Hz to 3 MHz. The set filter bandwidth is indicated opposite to the key.

Since, depending on the settings of the frequency span, not all filters allow for a useful display, their selection is restricted

Table 2.8-1	Settable	resolution	filters	depending
	on the fr	equency sp	an set

5030	Settable resolution filters
Shan
2.4 kHz 30 kHz	150 Hz	6 kHz	16 kHz	50 kHz	1 Mhz
30 kHz 1,2 MHz	6 kHz	16 kHz	50 kHz	30 kHz	3 Mhz
1,2 MHz 3.2 MHz	16 kHz	50 kHz	300 kHz	1 MHz
3,2 MHz 10 MHz	50 kHz	300 kHz	1 MHz	3 MHz
10 MHz 50 MHz	300 kHz	1 MHz	3 MHz

Function INPUT 1 / INPUT 2

This key permits to select the RF input via the connectors RF IN/OUT or RF IN 2. An external attenuation in the range from 0 to 100 dB can be entered for the two inputs. The numerical value is indicated in the upper display area with EXT ATT: - dB.

Funktion CENTER / START / SPAN / STOP

These keys permit to define the RF frequency range, in which the RF input signal is analyzed.

The user may select between display with center and span frequency or with start and stop frequency. Switchover is possible by actuating one of the two keys CENTER / START or SPAN / STOP.

If entries are made for one of these functions, the CMS automatically selects a resolution filter depending on the set span so as to guarantee useful recording.

Table 2.8-2 Selection of the optimum resolution filter depending on the frequency span entered

Span		Resolutionfilter
1.2 kHz	30 kHz	150 Hz
30 kHz	1.2 MHz	6 kHz
800 kHz	3.2 MHz	16 kHz
2.5 MHz	10 MH Z	50 kHz
8 MHz	50 MHz	300 kHz

In order to avoid unintentional, frequent variation of the resolution filters, Table 1.2 features hysteresis. A resolution filter setting is maintained as long as the frequency span is within the range of a row.

2.8.2 Settling the Reference Level

Eunction REELEV


The	reference	level	indicates	the	level	of	the
upp	er edge of	the di	splay, Thu	is. th	e leve	l of	the

recorded signal can easily be determined at any point. The limit values for the numerical entries of the

reference level are dependent on the selection of the RF input.

If signals are recorded via the connector RF IN/OUT, the reference level can be set at will in the range from -47 dBm to + 50 dBm.

For RF input 2, the reference level can be set in the range from -67 dBm to -27 dBm.

Possible units for the reference level are W, V and dBUV.

Function SCALE

This function permits to vary the scale in the ydirection. Settings of 2, 5 and 10 dB/graticule are possible. The set value is indicated to the left of the key.

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2.8.3 Freeze Mode

Function FREEZE

By pressing softkey 12 the Freeze-Mode will be switched on and off.

The Freeze function permits to stop the continuous build-up of the display. After pressing the key, the current build-up is finished and the curve then "freezed". A marker shaped as a cross appears at the maximum point of the curve. The frequency and level of the marker are indicated in the display.

The marker can then be moved at will on the curve using the rotary knob VAR.

During Freeze mode, FM-modulated signals can be demodulated at the frequency defined by the marker.

The settings for AM, FM, p M demodulation, IF filter (WIDE/NARROW), the demodulator status (ON/OFF/SQUELCH), and the setting of the loudspeaker (AMP softkey) are taken from the TX test.

A reference marker can be set at the position of the marker positioned before using keys SHIFT REF ENTER. The active cursor must be on the FREEZE key.

The reference marker is displayed in the form of a vertical line. If the reference marker is activated, the marker frequency and the marker level are displayed as a deviation from the reference position.

The reference marker function can be deactivated by keys SHIFT REF CLEAR. It is also cancelled with every new build-up of the display. The marker frequency displayed can be defined as centre frequency by way of softkey 13 (MKR → CF). Softkey 14 (MKR → REFLEV) serves to turn the indicated marker level into the reference level.

Thus the user is allowed to position a part of the recorded curve that is important to him into the middle of the picture with only a few keystrokes.

Both keys can only be operated if FREEZE has been activated. Pressing of these keys initiates a new build-up of the display.

Both actions lead again to a sweep in order to indicate the modified display.

2.8.4 Spectrum Analyzer in IEC-bus Mode

All functions of the RF spectrum analyzer an also be executed by a controller via IEC-bus commands.

The spectrum analyzer menu can be entered using the command:

DISPLAY:MENU 6.0".

In IEC-bus mode, the CMS is able to receive commands as well as to send back settings and measurement results to the controller.

The command SPECTRUM:MARKER permits to read in the entire curve point for point into the controller, however, FREEZE has to be activated before (SPECTRUM:FREEZE ON).

Example:

The controller sends the command:

"SPECTRUM:MARKER? 120MHZ".

Then the marker is set to position 120 MHz and the CMS sends the string:

"SPECTRUM:MARKER <marker level (W)>,<marker frequency (Hz)>".

The unit of the result returned by the CMS can be selected using the command

"UNIT <unit>".

The following table shows an overview of all IECbus commands in spectrum analyzer operation with the settings that can be sent back pointed out.

Page 98

2.9

Definition Menu for Tones

									the second s
0	RX-TEST	TONES		CMS -	Loca	al				TX-TEST	8
	STD	Std.01 ZVEI1	0;	Fix. Frq.	6	VDEW	12	unused	COUPLED	DECODE	9
1	RESET		1	ZVEI 1	7	EURO	13	SELCAL	INDEPENDENT	-> CODE	Ŭ
~	NO SPEC	1	2:	ZVEI 2	8	CCITT	14:	unused	10000 ms	DECODE	10
2	LENGTH	70 ms	3	CCIR	3	NATEL	15	CDCSS	10000 113	TIME	1.0
~	OTHER	70 m s	4:	EEA	10	DTMF	16	ATIS		1stTONE	11
3	PAUSE	0 ms	5	EIA	11:	VDEWd	17)	unused		2ndTONE	ļ · ·
	TONE O	2400.0 Hz		0.0	Hz	2	000.	0 Hz	0.0 Hz	TONE 8	12
4	TONE 1	1060.0 Hz		0.0	Hz	2	200.	0 Hz	0.0 Hz	TONE 9	\|
~	TONE 2	1160.0 Hz		0.0	Hz	2	799.	9 Hz	0.0 Hz	TONE A	13
5	TONE 3	1270.0 Hz		0.0	Hz		810.	0 Hz	0.0 Hz	TONE B
c	TONE 4	1400.0 Hz		0.0	Hz		970.	0 Hz	0.0 Hz	TONE C	14
0	TONE 5	1530.0 Hz		0.0	Ηz		886.	0 Hz	0.0 Hz	TONE D	Į
7	TONE 6	1670.0 Hz		0.0	Hz	2	599.	9 Hz	0.0 Hz	TONE E	15
1	TONE 7	1830.0 Hz		0.0	Hz		0.	0 Hz	U.O Hz	TUNE

Fig. 2.9-1 Main menu TONES

Starting with the main menus of the selection menu the main menu TONES (definition menu for tones) is reached by pressing the softkey TONES.

It contains all controls required to define parameters such as frequency, tone duration, pause duration and further parameters for output of the tone sequence and evaluation. The parameters are used in the transmitter and receiver test menus.

Softkey 0 allows for direct branching to the main menu for the receiver test and softkey 8 for branching to the transmitter test.

2.9.1 Selection of Standard


STD/RESET Function

The standards are named and called by numbers. These can be used according to the original standard or be modfied as required.

Number (= Std.No.)	unmodified	modified
0	Std.0 Fixed Frequencies	Std.0
1	Std.1 ZVEI 1	Std.1
2	Std.2 ZVEI 2	Std.2
З	Std.3 CCIR	Std.3
4	Std.4 EEA	Std.4
5	Std.5 EIA	Std.5
6	Std.6 VDEW	Std.6
7	Std.7 EURO	Std.7
8	Std.8 CCITT	Std.8
9	Std.9 NATEL	Std.9
10	Std.10 DTMF	Std.10
11	VDEWd
12	unused
13	SECAL

Standards 1 to 9 represent the usual single-tone sequences. For differentiation of unmodified and modified tone sequences the CMS displays standard number and name for unmodified tone sequences, but only the standard number for modified tone sequences.

The assignment of frequencies to numbers is displayed in the main menu for tones and can be modified. Standard 0 reacts like a completely normal tone sequence standard. In this case the frequencies are the fixed frequencies for the AF generators. Standard 10 is the dual-tone standard; it cannot be modified for evaluation purposes.

Softkey 1 allows for calling any standard in order to modify it (STD) or to reset the original parameters for the selected standard (RESET).. The SHIFT key is used to select between these two possibilities.

Page 99

The standard is called by entering softkey 1(STD)/number/ENTER. A standard is reset to the original state by entering softkey 1(RESET)/number/ENTER.

Note: Std. 11 (VDEW d) consists of the data records of Std. 1 (ZVEI 1) and STD. 10 (DTMF) and therefore can not be selected in this menu, but only from the CODE submenu 1 or DECODE submenu 2.

2.9.2 Tone Duration

NO SPC/LENGTH Function

Softkey 2 is assigned two functions. The SHIFT key is used to select the first or second function.

Softkey 2: NO SPEC

This function is used to define, which tone of the selective-call sequence is to be subjected to special tone duration.

Normally this is the first tone of extended tone duration compared to the other tones. The entry is made using softkey 2 (No SPC)/number (tone duration in ms)/ENTER.

Softkey 2: LENGTH

Each individual standard is assigned a tone duration, which can, however, also be influenced using softkey 2 (LENGTH). The duration can be selected independent of the other tones. It is entered using softkey 2 (LENGTH)/number (tone duration in ms)/ENTER.

2.9.3 Pause

Softkey 3 is assigned two functions. The SHIFT key is used for selecting the first or second function.

Softkey 3: OTHER

This softkey is used for determining the tone duration of the other tones by entering softkey 3 (OTHER)/number (tone duration in ms)/ENTER.

Softkey 3: PAUSE

The pause duration between the tones defined by entering softkey 3 (PAUSE)/number (tone duration in ms)/ENTER.

2.9.4 Frequency Definition

	ð.
TONE Function

The complete lower half of the screen is available for definition of frequencies. 8 softkeys with dual function (4 to 7, 12 to 15) are provided for the entry of 16 different frequencies or frequency pairs. The tone numbers correspond to the numbers (incl. A to F) of the "dialling number". The digits * and# are used for standard 10 (DTMF) instead of E and F. Again, SHIFT/softkey.. is used for switching between first and second function of a softkey.

A frequency or frequency pair can be entered for each digit, i.e. standards can consist of single or dual tones or even be mixed of single and dual tones. Single tones are produced by selecting 0 in the right softkey column. The selection of right or left column is made by pressing softkey 11. Again, SHIFT/softkey 11 is used to select the first function (left softkey column) or the second function (right softkey column) or vice versa.

The frequencies are entered by softkey../ number/ENTER. The frequencies are displayed in Hz.

The range for standard 0 is 100 Hz to 20 kHz and for standards 1 to 10 it is 300 Hz to 4 kHz.

The frequencies thus defined are valid for standards 0 to 10 (modified or unmodified) for output of tone sequences. For evaluation the frequencies of the first softkey column apply (modified or unmodified), however, only for standards 0 to 9. The lower tone number (digit) is decoded in case of frequency repeats. With standard 10 selected, the double tones of the unmodified standard are decoded.

Page 100

2.9.5 Coupling of Standards

DECODE → CODE Function

Softkey 9 is used to determine, whether coder and decoder work with the same standard or not. In the first case a change of standard for the coder automatically leads to a change of standard with the decoder and vice versa (normal operation). In the other case coder and decoder can be set individually.

2.9.6 Decoding Time

DECODE TIME Function

This function is especially of interest in automatic operation (IEC/IEEE bus and autorun control). The decoding time set here causes abortion of decoding after this time elapsed, independent of tones following or not.

The decoding time is entered using softkey 10/number (decoding time in ms)/ ENTER.

Application:

With acknowledgement call operation the CMS sends out a call, then evaluates the reply. Or the transceiver first sends a call; starting with this call the CMS first waits until the decoding time set via softkey 10 has passed, then continues the program by a reply selective call or any other action. This function is required for the signalling operation within the Swiss mobile telephone system NATEL B.

Rohde & Schwarz CMS 33 User manual

RADIOCOMMUNICATION SERVICE MONITOR CMS 33 840.0009.34

Contents

Basic Instrument and Options

Page

Page

3

Performance Test

Radiocommunication Service Monitor CMS 33

400 kHz to 1000 MHz

CMS 33 ID 0840.0009.34

CMS 33

Measurements

General Tests and Measurements

Signal sources

Measuring facilities

Filters

Other facilities

CMS 33

ID 0840.0009.34

CMS33 Specific Measurement - Added Value in the Avionic Fields

Impedance Matching

Auto-ILS /Autopilot CMS-B38 (optional)

SELCAL

SSB

Spectrum Monitor

VSWR

Instrument Configuration

Automatic Test Procedures

Preparations for Measurements

Exemplary Run of an Automatic Measurement

Exemplary Test Reports for COM testing

CMS 33

Test Routines, Programming and Software Management

Low Cost of Ownership

Instrument data

Timebase

Receiver measurements

Modulation modes

Transmitter measurements

VSWR meter

CMS 33

RF frequency counter

Frequency deviation meter

Phase deviation meter

AM depth meter

RF spectrum monitor

Transmitter measurements at 2nd RF input

Transmitter and receiver measurements

Modulation generator I and II

Distortion meter / Modulation distortion 100 Hz to 5 kHz (in 10-Hz steps)

SINAD meter

Frontnanel: 20 Hz to 20 kHz MIC: 100 Hz to 10 kHz 0.1 Hz same as timebase + 1/2 resolution Frontpanel: 10 µV to 5 V EME MIC: 100 µV to 350 mV 20 mA peak 10 μV. V <1 mV 1%, V ≥1 mV ±5%, V >1 mV Frontpanel <5 Q

CMS 33

ID 0840.0009.34

VOR/ILS generator 5)

General

CMS 33

AUTORUN Program

General data

Options

Antenna base CMS-Z35 ID.1066.7300.02

Remote Control Box CMS-Z34 ID.1065.4213.02

Carrying Bag CMS-Z44 ID.1066.7400.02

Ordering information

2 Operation

2.1 Explanation of Front and Rear Views

2.1.1 Front Panel

Display

Softkeys

-

Numeric keypad 0 to 9

Dimension key with ENTER function

5

Dimension key with ENTER function

7

Dimension key with ENTER function

Minus sign

9

Decimal point

Frontnanel: 20 Hz to 20 kHz MIC: 100 Hz to 10 kHz 0.1 Hz same as timebase + 1/2 resolution Frontpanel: 10 µV to 5 V EME MIC: 100 µV to 350 mV 20 mA _peak 10 μV. V <1 mV 1%, V ≥1 mV ±5%, V >1 mV Frontpanel <5 Q

VOR/ILS generator ⁵⁾