Acterna SPM-32A Operating Manual Download Page 71

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SPM-32A ... SPM-36A

4.2 Operation and features

4-41

1200, 400, 200, 100 Hz bandwidths

These bandwidths are useful for measuring the rms level in a
FM VFT channel to ITU-T specifications.

The level meter should be tuned to the center frequency of
the VFT channel under investigation.

Fig. 4-14

Typical receiver selectivity for
bandwidths 25 and 100 Hz

Nominal 3 dB bandwidth

Used for VFT system

100 Hz
200 Hz
400 Hz
1200 Hz

FM 120
FM 240
FM 480
FM 600 Bd

∆

Summary of Contents for SPM-32A

Page 1: ...SPM 32A SPM 36A Selective Level Meters Operating Manual BN 4033 00 82 ...

Page 2: ......

Page 3: ...s Operating Manual SPM 32A BN 4033 11 50 Hz to 620 kHz Series O SPM 33A BN 4033 01 50 Hz to 2 MHz Series O SPM 34A BN 4033 20 50 Hz to 2 MHz Series O SPM 35A BN 4033 30 50 Hz to 2 MHz Series Z SPM 36A BN 4033 36 50 Hz to 3 5 MHz Series AG ...

Page 4: ...ons Without written permission of the ITU T and or ETSI it is not permit ted to copy ITU T Recommendations or ETSI stand ards or parts thereof and or make them available to third parties Acterna Plymouth Ltd Eurotech House Burrington Way Plymouth PL5 3LZ Order no BN 4033 00 82 Edition 02 02 08 02 O Z AG Note Specifications terms and conditions are subject to change without prior notice Copyright 2...

Page 5: ... 1 3 1 Display contrast 3 1 3 2 Power supplies 3 2 3 2 1 AC line power 3 2 3 2 2 Battery power 3 3 3 2 3 Important note for all instruments 3 9 3 3 Switching on the instrument 3 10 3 4 Default settings reset 3 13 3 5 Electromagnetic compatibility 3 14 3 6 Cleaning the instrument 3 14 4 OPERATION 4 1 4 1 Overview 4 1 4 1 1 Connectors and keys 4 1 ...

Page 6: ...e frequency FREQ 4 26 4 2 3 1 Frequency entry TUNE keypad or steps 4 27 4 2 3 2 Frequency entry STEP keypad adjustable step width 4 29 4 2 3 3 SEARCH 4 31 4 2 3 4 AFC 4 37 4 2 4 Bandwidths 4 39 4 2 4 1 Setting the bandwidth 4 43 4 2 5 Level mode 4 46 4 2 5 1 Absolute level ABS 4 47 4 2 5 2 Level difference ABS REF reference level REF 4 50 4 2 5 3 Levels in dBm0 relative levels REL 4 54 4 2 6 Bargr...

Page 7: ... 4 67 4 2 8 Avoiding errors due to large common mode voltages 4 68 5 SPECIFICATIONS 5 1 5 1 Inputs 5 1 5 2 Frequency 5 2 5 3 Level measurements 5 5 5 3 1 Measured quantities 5 5 5 3 2 Level display 5 5 5 3 3 Display range 5 6 5 4 Error limits of the level display 5 7 5 4 1 Intrinsic error and variation with level 5 7 5 4 2 Variation of level display with frequency 5 9 5 4 3 Total error 5 10 ...

Page 8: ...nic ratio ak2 ak3 5 14 5 7 Demodulator 5 14 5 8 Memory 5 14 5 9 General specifications 5 15 5 9 1 Power supply 5 15 5 9 2 Ambient conditions 5 15 5 9 3 Electromagnetic compatibility 5 16 5 9 4 Safety information 5 16 5 10 Ordering information 5 17 Index ...

Page 9: ... and 600 Baud The SPM 35A Selective Level Meter is suitable for analyzing a mixture of frequencies and for measurements on ARI and RDS systems as well as telecontrol and ITU T FM VFT systems operating at 50 100 and 200 Baud The minimum bandwidth of 5 Hz is useful for measuring discrete signals starting at 50 Hz e g subaudio tones and composite signals such as spectral components of analog ARI and ...

Page 10: ... resolution allowing measurement of very small level differences The fast bargraph is very useful for alignment work A demodulator with an integral loudspeaker can be used to monitor the input signal The current result is also stored when the setup is stored the memory can be used as an electronic notebook up to 100 results The display provides a quick overview of all functions currently in use Ot...

Page 11: ...in yellow press the yellow key with the asterisks beforehand Example MAX HOLD Display of the highest RMS value which occurs during the observation time interval for use with fluctuating signals Graphic conventions The display illustrations have been generated using a computer and all essential features of the display are shown The part of the display referred to in the text is however shown in bol...

Page 12: ...1 2 About this handbook SPM 32A SPM 36A 1 4 Example in this figure BATTERY is written in bold script as this aspect of the instrument is being discussed 74 150 ...

Page 13: ...rposes for which they are intended In this regard please note the information contained in Section 1 Foreword and Section 5 Specifications Safety information for operation in a telephone network This device is designed for use on telephone lines It com plies with safety norm EN 41003 In this context the LNT 2 charger unit is required for a c line operation This assures that electrical circuits con...

Page 14: ...s a c line fuse Safety class The LNT 2 is a safety class II equipment to IEC 1010 1 VDE 0411 and IEC Publ 348 Faults If it is thought that the instrument is no or damage longer safe to operate the LNT 2 should be disabled and secured against unintentional operation Repairs Repairs must be correctly made In par ticular the construction characteristics of the LNT 2 must not be altered in any way whi...

Page 15: ...erature The LNT 2 is intended for use indoors and can be operated at temperatures between 0 and 50 C Ventilation When the LNT 2 is in use it should be placed such as to ensure adequate ventilation Condensation The LNT 2 must not be operated if condensation has formed on it If condensation is unavoidable as when the cold LNT 2 is brought into a warm room it must be allowed to dry out before being s...

Page 16: ...2 Safety information SPM 32A SPM 36A 2 4 Notes ...

Page 17: ...e instruments have an LCD display The display contrast depends on the light incident on the display the viewing angle Fig 3 1 Normal viewing angle The contrast can be adjusted by means of the contrast control in hole in side of set If you are viewing the instrument at a different angle adjust the contrast accordingly Tabelle 3 0 Bild 3 0 ...

Page 18: ...s two rechargeable batteries NiMH the BAZ 33 battery pack Note the operating instructions for the BAZ 33 battery pack 3 2 1 AC line power The LNT 2 AC Adapter Charger Unit BN 2071 90 021 is designated for powering the instrument from the a c line Plug the charger cable jack into the socket on the right hand side of the instrument If batteries or NiMHs are fitted plugging and unplugging the charger...

Page 19: ...o off circuit which normally operates after 15 minutes when batteries are used is disabled when theinstrument is operated from an a c adapter charger see section 3 3 on page 3 10 3 2 2 Battery power Two 9 V dry batteries or two rechargeable batteries are required The following are suitable Manganese alkaline batteries IEC 6LF22 or 6LR61 these give an operating time of about 8 hours or Rechargeable...

Page 20: ... ensures that the memory contents are retained Fig 3 3 Battery low warning The battery low warning BATTERY is temporarily cleared when you press a function key It will however reappear after about a minute because the battery voltage is measured at one minute intervals The warning will also be displayed when the instrument is powered by the AC adapter and there are no batteries in the set 74 150 ...

Page 21: ...contents are retained when the instrument is switched off Turn the instrument so that the back panel faces upward Use a coin or a screwdriver to turn the screw locking the battery compartment counterclockwise and remove the cover Holding the instrument in one hand shake out the batteries into your other hand taking care not to disconnect them Replace one battery at a time so that you do not lose a...

Page 22: ...must be below the batteries and must not be twisted Fig 3 4 How to replace the batteries in the battery compartment Replace and press down the cover while using a coin or a screwdriver to turn the screw clockwise If the lid does not fit properly do not use force the flat cable under the batteries may be twisted ...

Page 23: ...atteries are trickle charged If the warning BATTERY is displayed it is necessary to charge the batteries Connect the AC adapter Set the instrument to PERM ON mode no auto off Select the charge mode by entering the following keystrokes PERM ON and CHARGE should now appear in the display ON OFF PERM ON ON OFF CHARGE ...

Page 24: ...ere are dry batteries in the instrument and you select charge mode the instrument will confirm that charge mode has been selected but the batteries will not be charged as they do not have a charger contact The charge cycle is terminated if the AC line voltage fails Note If the LNT 2 AC adapter charger is connected a charging current will flow which is sufficient to compensate for the self discharg...

Page 25: ...g in the recycling of such items or to the place where new batteries are purchased Batteries purchased from Acterna can be returned to your nearest Acterna service center Removing the lithium battery before scrapping the instrument The following tells you how to remove the lithium battery from the instrument 1 Unscrew the lower enclosure shell 2 Remove the chassis from the upper enclosure shell 3 ...

Page 26: ...libration involves all subassemblies and lasts about 15 s The following text is displayed when calibration is in progress CAL When the CAL symbol disappears you can make measurements The current setting is the same as the setting when the instrument was last switched off You can also call up the calibration routine during measurements It is a good idea to calibrate the instrument if changes in amb...

Page 27: ... operates when the instrument is powered from the AC line in this case PERM ON is not marked If fitted the NiMH batteries are recharged in the instrument by repeating the key sequence and ON OFF see page 3 7 If these keys are pressed yet again this disables both charg ing mode and PERM ON mode The function is also cleared by switching the instrument off and then on again If the power supply to the...

Page 28: ...nd Setups cleared have been displayed the instrument will be set to its default settings see see section 3 4 on page 3 13 Any stored instrument setups have been cleared If the power supply fails while the instrument is switched on it is possible that the software may crash and the instrument will not switch back on when the power is restored To clear this condition perform a hardware reset by pres...

Page 29: ...settings at any time by pressing simultaneously to perform a hardware reset The message Default setting appears during the self test and the stored instrument settings are retained Default settings Selective level measurement Tuning frequency 8 kHz Bandwidth 3 1 kHz Output impedance 75 Ω unbalanced UNBAL ON OFF CLEAR ...

Page 30: ...his instrument can itself emit electromagnetic interference users must ensure that emissions remain within permitted limits Suitable measures should be taken to ensure that screening is contiguous When used in a balanced system the device under test itself must be adequately balanced Electromagnetic emissions can be further reduced by operating the instrument from dry or rechargeable batteries par...

Page 31: ...which is selected when the key sequence shift X is entered Inputs Coaxial input 75 Ω or high impedance Balanced input 75 Ω 150 Ω 600 Ω or high impedance Different versions of the instrument fitted with 120 124 135 or 140 Ω are available The input is selected automatically when the input impedance Z is selected see Z Ω 1 Tabelle 4 0 Bild 4 0 X X Y 1 30 dBm input distruction limit see section 4 2 2 ...

Page 32: ...e shift key by mistake you can cancel the entry by pressing CLEAR POWER For switching the instrument on or off If no keystroke is entered for 15 min the instrument switches itself off automatically when battery powered PERM ON CHARGE Each time this key sequence is entered the following sequence of functions is selected PERM ON Permanent operation Charge mode on 14 hours Both modes disabled Permane...

Page 33: ...elects or cancels AFC No effect when DEMOD WIDE or MAX HOLD have been selected To start frequency search press SEARCH search starts at tuning frequency Increase frequency by pressing or Decrease frequency by pressing or The search stops when the result REF or when the upper or lower frequency limit has been reached The search can be stopped by pressing TUNE or STEP The search function cannot be se...

Page 34: ...uency can be incremented or decremented by means of the 4 up down keys the stepwidth is F F can be set to any integer frequency value between 0 Hz and 620 kHz1 2 MHz2 or 3 5 MHz3 By entering this key sequence F you can alter the stepwidth Enter F kHz using the number keys and terminate with ENTER The up down keys can also be used to alter F 1 SPM 32A 2 SPM 33A 34A 35A 3 SPM 36A STEP STEP F ...

Page 35: ...nt REF Shows the difference between the measured level dB dBm and the stored reference level REF ABS REF by entering this key sequence the measured absolute level is stored as the new reference level Displays the reduced level in dB0 or dBm0 The absolute level is reduced by the relative level dBr dB0 dB dBr dBm0 dBm dBr The relative level can be entered by pressing dBm0 REL dBr allows you to modif...

Page 36: ...d idea to select the 3 1 kHz filter and to tune to the centre of the bandwidth The volume can be adjusted with the up down keys MAX HOLD displays the max level reached by keyed signals carrier telegraphy SCALE EXPAND expands bargraph display 1 dB div 0 1 dB DOT on off Non expanded display 10 dB div 1 dB DOT AVRG result averaging slow on off resolution 0 01 dB Clears any entry which has not been te...

Page 37: ...2 4 Broadband measurement over entire frequency range Selective measurement at 25 Hz bandwidth Selective measurement the bandwidth alternates between 100 Hz and 200 Hz Selective measurement the band width alternates between 400 Hz1 and 1200 Hz Selective measurement at 3 1 kHz bandwidth 1 300 Hz also available as option for SPM 34 WIDE 4 25 6 100 200 6 400 1200 WIDE 3 1 kHz ...

Page 38: ... key sequence toggles between the balanced BAL and the coaxial input UNBAL TEST CONFIG This key sequence calls up the test and service programs see service manual The software version and the options fitted are shown in the display Press CLEAR or to exit this mode takes a few seconds or switch the instrument off and then on again For terminating entries CAL calls up the calibration routine 1 75 2 ...

Page 39: ... frequency The coarse step width depends on bandwidth the fine step width is 1 Hz SEARCH Starts the search function STEP Increases or decreases the tuning frequency by F adjustable step width F is entered by entering the key sequence STEP After the key sequence STEP has been entered F can be increased or decreased in steps of 10 Hz or 1 Hz After the key sequence ABS REF has been entered the stored...

Page 40: ...an then be entered 0 to 99 or altered with the up down keys the entry is terminated with ENTER8 STO MEM stores the current setup and result at an address between 0 and 99 see RCL MEM DISPLAY MEM displays a setup that has been stored The last value that was measured before the setup was stored is also displayed It is not possible to make measurements when the setup is being displayed The display is...

Page 41: ...ans the character in the 2nd row and 15th column Row A shows The measured level when ABS ABS REF dBm0 or MAX HOLD are entered USB or LSB when DEMOD is entered Row B shows The result as a bargraph coarse MAX HOLD when DEMOD max level is selected FREE if there is nothing stored at the address when DISPLAY MEM is entered Row C shows The receive frequency when TUNE SEARCH or STEP are pressed WIDEBAND ...

Page 42: ...s stored as the reference level D13 storing STO or recalling RCL a set up A2 the input level is too high or when wide band measurements are being made too low C2 3 when the key sequence STEP is entered you can change the frequency stepwidth by f S C3 when you press STEP the tuning frequency can be incremented or decremented by f C3 when SEARCH has been pressed search mode has been selected but not...

Page 43: ...e the LSB of the CF signal is demodulated and output via the built in loudspeaker DEM UPPER SB A when DEMOD is pressed the USB of the CF signal is demodulated and output via the built in loudspeaker DSP D14 when and are pressed DSP and an address are displayed alternately The memory contents at this address are shown but the instrument is not set to this setup MAX HOLD B when and DEMOD is pressed ...

Page 44: ... function has been selected the possibilities are marked on the right and left hand edges of the display AFC AVRG Display averaging slow the resolution of the level display is 0 01 dB BW Shows which bandwidth has been selected CHARGE Batteries are charging EXPAND Bargraph is expanded INPUT U Either 75 Ω 150 Ω or 600 Ω has been selected as input impedance INPUT High input impedance1 INPUT BAL The b...

Page 45: ... the built in loudspeaker indicated by monitor in table 4 1 Wideband level measurements Table 4 1 is a summary of the functions in each operating mode Table 4 1 Summary of instrument functions Function selected using keypad Wideband receiver Selective receiver Meas Monitor Wideband meas WIDE Receive frequency TUNE STEP Search SEARCH AFC AFC Level reference ABS ABS REF dBm0 Bandwidths see section 4...

Page 46: ...2 2 on page 4 22 Set the receive frequency Use TUNE STEP or SEARCH frequency search see section 4 2 2 on page 4 22 Absolute voltage level power level level difference or level in dBm0 Use ABS ABS REF or dBm0 see section 4 2 5 on page 4 46 Select one of the bandwidths Use the keys in the group marked BANDW Hz and the shift key 4 5 or 6 see section 4 2 4 on page 4 39 Reading the display in selective...

Page 47: ... REF or dBm0 see section 4 2 5 on page 4 46 You cannot change the frequency shown in row C unless a flashing arrow appears before the entry press TUNE or STEP If a appears to the right of the level the level is out of range To check the total level select the wideband receiver by pressing WIDE Return to the selective mode by pressing TUNE or STEP the bandwidth is automatically set to 3 1 kHz You c...

Page 48: ...eiver by pressing WIDE WIDEBAND appears in the 3rd row of the display Select absolute voltage level power level difference or level in dBm0 Use ABS ABS REF or dBm0 see section 4 2 5 on page 4 46 If necessary select expanded bargraph and the averaging facility Use the keys in the group marked SCALE 7 or 8 see section 4 2 6 on page 4 56 Reading the display in wideband mode Fig 4 2 Wideband mode disp...

Page 49: ...w D Relative level reference level or memory function or blank The mean value is measured The result shown is however the rms value of a sinusoidal signal with the same frequency If no result is displayed press ABS ABS REF or dBm0 see section 4 2 5 on page 4 46 to the left of the result means level out of range ...

Page 50: ...channel Fig 4 3 SSB demodulation The carrier and the USB have been suppressed Setting the instrument Select the input and the input impedance Use the keys in the group marked Z Ω and shift 1 2 or 3 see section 4 2 2 on page 4 22 Change the receive frequency Use TUNE or STEP see section 4 2 3 on page 4 26 The centre of the band is converted to 2 kHz provided the instrument has been tuned to the cen...

Page 51: ... 6 see section 4 2 4 on page 4 39 Adjust the volume using the up down keys Volume up with or in 2 or 6 dB steps Volume down with or in 2 or 6 dB steps The loudspeaker volume can only be set if the displayed mode line DEM UPPER SB is marked by an arrow If no arrow is displayed press DEMOD once or twice The frequency can be fine tuned by means of the up down keys TUNE or STEP Fig 4 4 Example showing...

Page 52: ...principle to the other versions With the instrument you have the choice of 2 selectable inputs Coaxial input Input impedances 75 Ω or 6 5 kΩ Balanced input Input impedances 75 Ω 150 Ω 600 Ω or 13 kΩ Only one input should be selected at any one time Selecting the input and the input impedance The input and the input impedance are selected together WARNING 30 dBm The input level a c d c must not exc...

Page 53: ... input type and the input impedance are selected together It is possible to select them separately The coaxial input can thus have an input impedance of 150 Ω or 600 Ω This should not be done at high frequencies as errors greater than those stated in the specifications will be introduced You can select the other input type by entering The input impedance remains the same The balanced input has bee...

Page 54: ...tor leaving only the high impedance of the input amplifier 6 5 kΩ or 13 kΩ resp A small square at the right hand edge of the display shows whether Z or has been selected Fig 4 5 Examples illustrating input selection Left Coaxial input Zin 75 Ω Right Balanced input high impedance 1 1 The simultaneously marked impedance value is needed during dBm display for power computation During dB display it is...

Page 55: ...th an output impedance of 0 Ω and various input impedances are selected Power levels dBm are referred to 1mW When a different input impedance is selected a different level will be displayed by the instrument Table 4 2 Power levels for 0 775 V into Zin Table 4 3 Voltage for 0 dBm into Zin P 1 mW Z Ω 50 75 124 135 140 150 600 Lp dBm 10 8 9 03 6 85 6 48 6 32 6 02 0 Z Ω 50 75 124 135 140 150 600 Vz V ...

Page 56: ...receive frequency to the frequency of the input signal SEARCH Using this facility you can automatically search for signals in a certain frequency range that exceed a certain level threshold STEP For changing the receive frequency using the number keys or in steps using the up down keys step width F The step widths for the TUNE function are fixed but STEP can be used to set a step width F between 0...

Page 57: ...pressing The receive frequency can be set in the following ways Numerical entry using the number keys In steps using the up down keys Fig 4 6 Typical display in TUNE mode Entering a frequency using the number keys Example 1 2345 MHz Note When you enter a number the instrument always takes it to be in kHz TUNE 150 74 1 2 3 4 5 ENTER ...

Page 58: ... to 10 Hz when a bandwidth 25 100 Hz is selected When TUNE mode has been selected the up down keys are a good way of fine tuning the instrument SPM 35A Table 4 4 Changing the frequency in steps Bandwidth Hz Step width Hz 5 1 2 25 100 200 400 1 10 3 1 kHz 1 200 Frequency is incremented by 10 100 or 200 Hz Frequency is increased by 1 Hz Frequency is decreased by 1 Hz Frequency is decreased by 10 100...

Page 59: ... 10 Hz instead of 1 Hz 4 2 3 2 Frequency entry STEP keypad adjustable step width The selective receiver is selected when the following key is pressed The receive frequency can be altered in the following ways Numerical entry using the number keys like TUNE In steps of F using the up down keys The step width F can be adjusted Fig 4 7 Typical STEP mode display STEP 74 150 ...

Page 60: ...Always enter the frequency in kHz Frequency steps By pressing The previously stored value will be used unless altered Changing the step width F Change step width mode is selected by entering 1 2 3 4 5 ENTER the frequency is increased by F the frequency is decreased by F or or By pressing STEP F ...

Page 61: ...kHz Always enter the frequency in kHz When you press STEP the instrument will start to measure the receive frequency can be incremented or decremented by the new frequency step 4 2 3 3 SEARCH When SEARCH mode is selected the instrument searches automatically for signals that are greater than a set threshold value adjustable The receive frequency can be increased or decreased starting from a select...

Page 62: ...d with wideband receiver WIDE is not more than 60 dB above the reference level 40 dB for a bandwidth of 25 Hz 100 Hz it will not be found Fig 4 9 A typical search display Start frequency Equal to the current receive frequency It can be entered as described in 4 2 3 1 TUNE and 4 2 3 2 STEP Threshold The current value can be used or a new value can be entered Default setting 20 dB or dBm Example Set...

Page 63: ... prior to switching over to voltage measurement The input value converted to a voltage is displayed in line A also Caution For dBm the proper impedance value must be selected beforehand Fig 4 10 Voltage mode display of threshold level threshold set in dB and mV Fig 4 11 Voltage mode display of threshold level threshold set in dBm and mV 74 150 74 150 ...

Page 64: ...he direction of the search is indicated by an arrow in front of the current frequency in the display The search direction can be reversed during a search if required Pausing in the search End the search SEARCH Frequency will increase Frequency will decrease or or or dBm0 ABS or STEP TUNE TUNE ...

Page 65: ...n and features 4 35 Further information AFC is activated automatically The uncertainty in the comparison of the signal level and the THRESHOLD value is 1 dB Signal will be found Signal level always perhaps never REF 1 dB REF 1 dB ...

Page 66: ...unction has been acti vated AVRG key Table 4 5 Search speeds as a function of bandwidth Bandwidth AVRG On Off 5 Hz 8 Hz s 50 Hz s 25 Hz 40 Hz s 250 Hz s 100 Hz 150 Hz s 1 4 kHz s 200 Hz 300 Hz s 2 9 kHz s 300 Hz 450 Hz s 4 4 kHz s 400 Hz 600 Hz s 6 0 kHz s 1 2 kHz 1 8 kHz s 36 kHz s 1 74 kHz 2 6 kHz 50 kHz s 3 1 kHz 4 6 kHz s 100 kHz s ...

Page 67: ...s a discrete signal of sufficient amplitude in the passband of the selected filter AFC cannot be used if DEMOD mode has been selected It is a good idea to activate AFC if you want to quickly tune the receiver to the centre of the filter the signal frequency is fluctuating or you want to monitor a signal for a long time AFC operating range Fig 4 12 AFC capture and holding range e g SPM 33A 2 0 Hold...

Page 68: ...a frequency and the receiver is tuned to the signal frequency The square beside AFC flashes if the AFC has not locked because the signal frequency is outside the capture range The AFC will not lock if the signal frequency is fluctuating rapidly or there are large jumps in the signal frequency select a larger bandwidth the signal level is too small Switching off AFC AFC TUNE or WIDE DEMOD or AFC TU...

Page 69: ...type The following section explains the uses and setting of the various bandwidths Band width SPM 32A SPM 33A SPM 34A SPM 35A SPM 36A 5 Hz 25 Hz 100 Hz 1 1 1 200 Hz 300 Hz 2 400 Hz 1200 Hz 1 74 kHz 3 1 kHz 1 100 Hz bandwidth instead of 25 Hz option BN 4033 00 52 2 300 Hz bandwidth instead of 400 Hz option BN 4033 00 24 Table 4 6 Bandwidths ...

Page 70: ...ignals can be measured precisely with the 5 Hz bandwidth This is also useful for measurement of spectral lines in the new digital radio data system RDS Fig 4 13 Typical receiver selectivity at a bandwidth of 5 Hz 25 Hz bandwidth This narrow bandwidth filter is suitable for measuring pilot levels or carrier leaks unkeyed signals in VFT channels the modulation frequency half transmission frequency a...

Page 71: ...he rms level in a FM VFT channel to ITU T specifications The level meter should be tuned to the center frequency of the VFT channel under investigation Fig 4 14 Typical receiver selectivity for bandwidths 25 and 100 Hz Nominal 3 dB bandwidth Used for VFT system 100 Hz 200 Hz 400 Hz 1200 Hz FM 120 FM 240 FM 480 FM 600 Bd F ...

Page 72: ...hat of the weighting filter specified by the ITU T O 41 see figure 4 15 page 4 42 3 1 kHz bandwidth This is the same bandwidth as a telephone channel Using this bandwidth you can measure the power and unweighted noise carried by single telephone channels Warning The 3 1 kHz and 1 74 kHz bandwidths should only be used when the receive frequency is greater than 2 kHz Fig 4 15 Typical receiver select...

Page 73: ...n the 25 Hz filter applies in principle to the 100 Hz filter There is a choice of 3 bandwidths when the selective mode has been selected If you are in wideband mode you can switch to selective mode by selecting one of these bandwidths see section 4 2 1 1 on page 4 16 To select a new bandwidth e g 3 1 kHz enter Fig 4 16 The example shows the 25 Hz is selected 4 6 1 74 k 5 3 1 k 25 3 1 k 6 3 1 Hz BW...

Page 74: ...the SPM 34A Indication of filter selected A number is shown in the lower left hand corner of the display Fig 4 17 The example shows the 3 1 kHz filter is selected Selecting the bandwidth Note Bandwidth selection is explained using the SPM 34A as an example The bandwidth is selected using the 4th row of keys 4 5 6 WIDE 25 100 200 400 1200 3 1 k ...

Page 75: ...certain values the and number keys may need to be pressed twice in succession Example Setting the 1200 Hz filter bandwidth If the current bandwidth setting is 400 Hz or 3 1 kHz or when changing from wideband to selective reception If the current bandwidth is 25 100 or 200 Hz WIDE 3 1 k 6 400 1200 6 400 1200 6 400 1200 400 Hz filter 1200 Hz filter switched on ...

Page 76: ...ce Levels express the ratio of two quantities One quantity may be a reference i e a certain power or a certain voltage dBm dB and these are referred to as absolute levels Relative levels are the difference between two levels The instrument can measure the following absolute voltage and power levels ABS level differences ABS REF level in dBm0 4 25 ABS dBm0 ABS REF ABS REL dBr REF REF ...

Page 77: ... 775 V When this reference voltage is applied across a 600 Ω resistor a power of 1 mW is dissipated Designation Result Constants Units Absolute level ABS dB dBm Level difference1 ABS REF dB Reference level1 2 REF dB dBm dBm0 dB0 dBm0 ABS REL dB0 dBm0 Relative level 1 2 REL dBr dBr 1 No dB dBm selection 1 Constants which are not recalculated when Constant which are not recalculated when dB dBm swit...

Page 78: ...owing can be measured either the absolute power voltage level in dBmdB or the absolute power level in dBm after Selecting voltage level or power level dB dBm You can toggle between voltage level dB and power level dBm by pressing the following keys When you select a new input impedance the power dissipated is altered thus altering the power level reading see section 4 2 2 on page 4 22 The referenc...

Page 79: ... voltage The input voltage display is 4 digit The instrument automat ically selects the correct display units µV mV V for the measurement e g 732 1 µV AC or 24 36 mV AC or 1 256 µV AC Only absolute measurements can be made in this mode which is automatically selected regardless of the previous measurement mode used It is not possible to enter a refer ence voltage level Selective measurement 1 µV t...

Page 80: ...le to store a result and use it as the reference level If the level mode is changed dB dBm or the input impedance is changed the reference level is not adjusted accordingly The level difference can be measured when the following key is pressed The reference level is shown in line D of the display Level difference dB measured absolute level dB dBm stored reference level dB dBm ABS REF Example Measu...

Page 81: ... keys Reference level REF When making level difference measurements the instrument refers the measured absolute level to a reference level ABS REF The reference level can be set in the following ways By entering a numerical value using the number keys or by incrementing decrementing the level by means of the up down keys By storing a result and using it as the reference level Only one reference le...

Page 82: ...ing key sequence The current value of the reference level is shown in row D of the display You can now enter a new reference level e g 26 dB Changing the reference level in steps REF ABS 2 6 ENTER The reference level is increased by 1 dB The reference level is increased by 0 1 dB The reference level is reduced by 0 1 dB The reference level is reduced by 1 dB ...

Page 83: ...ner of the display as an acknowledgment Example Attenuation of a channel filter at 4 kHz The reference frequency is 1 kHz The difference between the levels measured at 1 kHz and 4 kHz is to be determined Tune the receiver to 1 kHz reference frequency Measure the voltage level at 1 kHz Store the measured level as the reference Tune the receiver to 4 kHz ABS REF ABS REF TUNE 1 ENTER ABS ABS REF ABS ...

Page 84: ...0 Absolute level Level in dBr Fig 4 20 Level plan for a transmission system At the 0 TLP 0 dBr point the level in dBm0 is equal to the absolute power level For other points in the transmission system dBm0 dBm dBr It must be ensured that the correct relative level and the correct input impedance are used for other test points ABS REF ...

Page 85: ... is the difference in level between any point in a transmission system and the level at a reference point At the reference point the relative level equals 0 dB see figure 4 20 page 4 54 The relative level is determined by the level plan and so need not be measured It is entered as a constant The current value of the reference level is shown in row D of the display The relative level can be set in ...

Page 86: ...100 setups and hence up to 100 reference levels can be stored using the STO MEM facility Fig 4 21 Selective level measurement in dBm0 Row D shows the relative level in dBr REL It is entered by pressing and dBm0 The receiver can be precisely tuned to the input frequency using the up down keys 4 2 6 Bargraph AVRG MAX HOLD 4 2 6 1 Bargraph The instrument has a bargraph that has certain similarities w...

Page 87: ...le can be selected or cancelled by entering the sequence The expanded scale is a relative scale and should be thought of as folding back onto itself The display increases or decreases by 10 dB at 11 dB or 1 dB hysteresis to prevent display jitter at 0 or 10 dB In other words only the relevant section of an expanded display is shown 120 100 80 60 40 20 0 20 EXPAND 7 ...

Page 88: ...ting signals It can be switched on and off by entering the following sequence The averaging facility has the following effects The time constant of the rectifier is increased The current level shown by the display is calculated using the following formula Display value 7 x old value new value 8 The display resolution increases from 0 1 dB to 0 01 dB 10 9 8 7 6 5 4 3 2 1 0 dB AVRG 8 ...

Page 89: ...his allows you to check idle channels for intermittent inter ference or overvoltages as long as the signal is present for long enough for the autorange function to operate Note Do not use the MAX HOLD function when using the SEARCH function The MAX HOLD function can also be switched on and off during a measurement by pressing Fig 4 22 MAX HOLD function activated MAX HOLD DEMOD 74 150 ...

Page 90: ...s stored setup STO MEM Stores current setup and latest result DISPLAY MEM Displays a setup stored in memory MEM OFF Cancels the current memory function 4 2 7 1 Addresses Addresses 0 to 99 are used to store setups One setup can be stored at each address When STO MEM RCL MEM or DISPLAY MEM are selected an address number is displayed in the lower right hand corner of the display The arrow to the righ...

Page 91: ...display when RCL MEM is selected The address in this case 34 can now be modified Incrementing or decrementing the address number The repeat mode is selected if any of these keys are held down 74 150 Address is increased by 5 Address is increased by 1 Address is decreased by 1 Address is decreased by 5 ...

Page 92: ...ber keys When you press ENTER the setup and the current result are stored at the address displayed Entry is acknowledged by STO which appears in the lower right hand corner of the display If you store a setup at an address where a setup has already been stored the old setup will be overwritten You can determine beforehand whether an address is free or not by using DISPLAY MEM see section 4 2 7 4 o...

Page 93: ... an electronic notebook which tells you the settings you have used as well as the results Example showing storage of three results The initial address is 25 The setup selected is always the same The initial address is entered using the number keys The address number can then be incremented using the key 1st result 2nd result 3rd result Quit memory mode by entering 2 5 ENTER STO MEM ENTER address 2...

Page 94: ...number can be modified using the up down keys or by entering a new address number using the number keys see section 4 2 7 1 on page 4 60 When ENTER is pressed the instrument is set to the recalled setup and the instrument starts measuring An exclamation mark to the left of the address number e g 25 acknowledges the previous procedure Quit memory mode by pressing and then MEM OFF You can also quit ...

Page 95: ... the RCL MEM function each time Example Recall three setups starting at address is 12 The first address is entered using the number keys This can then be modified using increment 1 1st setup 2nd setup 3rd setup Quitting memory mode 2 5 ENTER RCL MEM ENTER the address is increased by 1 to 13 ENTER the address is increased by 1 to 14 MEM OFF ...

Page 96: ...he same address after a measurement has been made The setup itself is unchanged The new results can be viewed later using DISPLAY MEM Example Updating results starting at address 25 Recall setup at address 25 Make measurement and then re store Increment address by 1 and recall setup and so on 2 5 ENTER RCL MEM ENTER STO MEM ENTER or RCL MEM ENTER RCL MEM ...

Page 97: ...articular address FREE is shown in the display Fig 4 24 DISPLAY MEM display address is unoccupied DSP and the address number flash on and off alternately Example How to check what is stored at address 0 1st setup After you have selected DISPLAY MEM by entering and then DSP and 0 the address number flash on and off alternately If you alter the address number using the up down keys you do not need t...

Page 98: ...d interference voltages may result Stray fields are found in the areas surrounding high tension lines for example Spurious signals will be induced in a twin core cable connected to the balanced input of the instrument in such cases resulting in an incorrect measurement due to the finite common mode rejection ratio of the input circuit These errors can be minimised by either Use a CF cable with goo...

Page 99: ...ated 5 1 Inputs Coaxial input Versacon 9 Universal Connector compatible with all common connector systems Input impedance selectable 75 Ω high impedance Return loss SPM 32A 33A 34A 35A 40 dB SPM 36A 50 Hz to 2 MHz 40 dB 50 Hz to 3 5 MHz 35 dB Balanced input 3pole CF socket Input impedance selectable 75 Ω 150 Ω 600 Ω high impedance Return loss at f 10 kHz 40 dB Tabelle 5 0 Bild 5 0 ...

Page 100: ...l and common mode signal Input level 30 dBm D C input voltage 60 V from Zout 600 Ω 5 2 Frequency Frequency range SPM 32A 50 Hz to 620 kHz SPM 33A 34A 35A 50 Hz to 2 MHz SPM 36A 50 Hz to 3 5 MHz Frequency setting Manually using keypad resolution 1 Hz Automatically using AFC SPM 32A 40 dB SPM 33A 34A 35A 30 dB SPM 36A 25 dB Frequency range Hz 50 100 620 k 1 62 M 2 M 3 M 3 5 M ...

Page 101: ...z 1 Hz at B 400 Hz 10 Hz AFC capture range SPM 32A 33A 36A at B 25 Hz 50 Hz at B 100 Hz 100 Hz at B B 1 74 kHz 1 5 kHz SPM 34A 35A at B 5 Hz 10 Hz at B 25 Hz 50 Hz at B 100 Hz 90 Hz at B 200 Hz 150 Hz at B 300 Hz 200 Hz1 at B 400 Hz 220 Hz at B 3 1 kHz 1 5 kHz SPM 34A at B 1 2 kHz 1 0 kHz SPM 35A at B 5 Hz 10 Hz 1 Option 4033 00 24 SPM 34A ...

Page 102: ...e between max signal level and response threshold SPM 32A 33A 35A 36A at B 100 Hz 40 dB at B 1 74 kHz 60 dB SPM 34A 35A at B 5 Hz1 30 dB bei 25 Hz B 1 2 kHz 40 dB at B 3 1 kHz 60 dB Frequency display 7 digit resolution 1 Hz Error limits Frequency setting error limits including aging for 1 year 3 x 10 6 x f 1 Hz 1 SPM 35A ...

Page 103: ...775 V in dB Level difference in dB referred to reference level REF in dBm dB Reduced level in dBm0 dB0 referred to relative level dBr Voltage in µV mV V 5 3 2 Level display Digital display max resolution 0 01 dB Quasi analog bar graph as trend display Scale selectable SPM 32A 33A 36A 140 dB 10 dB SPM 34A 35A 110 dB 10 dB Resolution expanded display 0 1 dB ...

Page 104: ...10 kHz Wideband Coaxial 75 Ω 120 to 20 dBm 50 to 20 dBm Balanced 75 Ω to 150 Ω 600 Ω 105 to 20 dBm 110 to 10 dBm 50 to 20 dBm 60 to 10 dBm Voltage 8 µV to 3 8 V 1 mV to 3 8 V Input Selective f 10 kHz Wideband Coaxial 75 Ω 901 to 20 dBm 50 to 20 dBm Balanced 75 Ω to 150 Ω 600 Ω 901 to 20 dBm 1002 to 10 dBm 50 to 20 dBm 60 to 10 dBm Voltage 15 µV to 3 8 V 1 mV to 3 8 V 1 for 5 Hz bandwidth 80 dBm 2 ...

Page 105: ...rror limits for voltage measurements in dB can be converted linearly to 0 1 dB is approx 1 2 of the measured value 5 4 1 Intrinsic error and variation with level at 10 kHz and 23 3 C table values in dB SPM 32A 33A 36A Table 5 4 Intrinsic error and variation with level SPM 32A 33A 36A Balanced all bandwidths 0 4 0 9 Coaxial B 100 Hz B 100 Hz 0 3 0 1 0 3 0 4 0 6 B 25 Hz 0 4 Level range dBm 75 135 15...

Page 106: ... 34A SPM 35A 5 Hz bandwidth Table 5 6 Intrinsic error and variation with level SPM 35A Balanced 0 4 0 9 Coaxial 0 3 0 1 0 3 0 4 Level range dBm 75 135 150 Ω 20 0 0 60 70 80 Level range dB dBm 600 Ω 10 70 80 90 Balanced 0 4 0 5 Coaxial 0 3 0 1 0 3 Level range dBm 75 135 150 Ω 20 0 0 60 70 Level range dB dBm 600 Ω 10 70 80 ...

Page 107: ...referred to 10 kHz the input level at 40 dB above the intrinsic noise level Table 5 8 Variation of level display with frequency Balanced 0 4 0 9 Coaxial 0 3 0 1 0 3 0 4 Level range dBm 75 135 150 Ω 20 0 0 60 70 80 Level range dB dBm 600 Ω 10 70 80 90 Coaxial Z 75 Ω 0 6 0 3 0 5 0 6 0 7 0 9 Balanced Z 75 to 150 Ω 0 3 0 5 0 6 0 7 0 9 Z 600 Ω 0 4 0 6 0 7 0 8 1 0 Frequency range Hz 50 100 620 k 1 62 M ...

Page 108: ... to 1 62 MHz 0 9 dB 1 3 dB f 50 Hz to 2 MHz 1 0 dB 1 4 dB f 50 Hz to 3 MHz 1 1 dB 1 5 dB f 50 Hz to 3 5 MHz 1 3 dB 1 7 dB Error limits wideband 2 f 200 Hz to 620 kHz 0 8 dB f 200 Hz to 1 62 MHz 1 0 dB f 200 Hz to 2 MHz 1 1 dB f 200 Hz to 3 MHz 1 2 dB f 200 Hz to 3 5 MHz 1 4 dB Level range dBm 75 135 150 Ω 20 40 80 901 1 RMS measurement Level range dB dBm 600 Ω 10 50 90 1002 2 Average measurement d...

Page 109: ... f 200 Hz to 1 62 MHz 0 9 f 50 Hz to 2 MHz 1 0 Error limits wideband 2 f 200 Hz to 620 kHz 0 8 f 200 Hz to 1 62 MHz 1 0 f 200 Hz to 2 MHz 1 1 Level range dBm1 75 135 150 Ω 2 1 RMS measurement 2 Average measurement display of rms value for sinusoidal signals 20 35 75 60 3 3 Values in brackets apply to 5 Hz bandwidth Level range dB dBm 600 Ω 10 45 85 70 3 ...

Page 110: ... Hz1 1 74 kHz 3 1 kHz 1 74 kHz 10 3 1 kHz 15 24 Hz 80 Hz 1450 Hz 2 7 kHz 250 Hz 400 Hz 2 kHz 2 kHz Option replaces 25 Hz Values for 10 to 35 C 3 dB band width nominal Attenuation at frequency offset f 0 5 dB 3 dB 17 dB 50 dB 25 Hz 100 Hz 200 Hz 400 Hz 1200 Hz 3100 Hz1 25 Hz 60 Hz 120 Hz 360 Hz 12 Hz 45 Hz 100 Hz 200 Hz 600 Hz 100 Hz 200 Hz 400 Hz 1200 Hz 100 Hz 350 Hz 700 Hz 1 kHz 2 kHz3 2 kHz3 1 ...

Page 111: ...0 dB 3 dB band width nominal Use withVFT systems Attenuation at frequency offset f 0 5 dB 3 dB 17 dB 50 dB 5 Hz 25 Hz 100 Hz 200 Hz 400 Hz 3100 Hz1 FM 120 FM 240 FM 480 25 Hz 60 Hz 120 Hz 5 Hz2 12 Hz 45 Hz 100 Hz 200 Hz 2 7 kHz2 10 Hz 50 Hz 100 Hz 200 Hz 400 Hz 20 Hz3 100 Hz 350 Hz 700 Hz 1 kHz 2 kHz4 1 Effective noise bandwidth 3 1 kHz 15 2 Bandwidth for attenuation 3 dB 3 Stop band attenuation 5...

Page 112: ...ut levels 10 dBm SPM 32A 33A 36A 60 dB SPM 34A 55 dB SPM 35A at B 25 Hz to 3 1 kHz 55 dB at B 5 Hz 40 dB 5 7 Demodulator Single sideband demodulation selectable upper or lower sideband Built in loudspeaker adjustable volume 5 8 Memory 100 setups can be stored and recalled The setups are cleared by being overwritten ...

Page 113: ...le batteries e g Varta V7 8R Sanyo N 6PT Battery pack BAZ 33 battery pack can be removed from instrument AC line operation only with LNT 21 14 to 15 V approx 100 mA Measurements can be made during battery charging Operating time from Dry batteries approx 8 h Rechargeable batteries approx 2 h BAZ 33 Battery Pack approx 8 h 5 9 2 Ambient conditions Ambient temperature Nominal range of use 0 to 50o C...

Page 114: ...sions w x h x d in mm 110 x 200 x 60 Weight with batteries approx 1 kg 5 9 3 Electromagnetic compatibility EMF emission to CISPR 22 class B EN 55022 and EN 50081 11 Refer also to section 3 5 Immunity to interference to IEC 801 2 3 4 and EN 50082 11 5 9 4 Safety information Safety measures to IEC 1010 11 Safety class of LNT 2 Safety class II Protective measures affecting connection to telephone net...

Page 115: ...BN 4033 36 but with noise measurements in dBrnC WECO connectors 4 1 All instruments are fitted with basic 75 Ω Versacon 9 connector and BNC insert Other inserts should be ordered when ordering the instrument see Versacon 9 data sheet for details The instruments are supplied with 2 dry batteries carry strap 2 A bandwidth of 1 95 kHz instead of 1 74 kHz 3 All instruments are fitted with basic 75 Ω V...

Page 116: ...tery Pack BN 4033 00 10 strap on NiMH unit TR7 NiMH batteries two required BN 820 00 50 with charger contact LNT 2 A C Adapter Charger BN 4071 90 02 Please specify power cord required 4 European plug K 490 U S Japanese plug K 491 U K plug K 492 Australian plug K 493 SDG 40 Balanced Attenuator BN 608 00 01 PLCP 40 Coaxial Attenuator BN 9203 01 1 To be ordered together with the instrument can only b...

Page 117: ...32A SPM 36A 5 10 Ordering information 5 19 Leather case no 10 BN 0926 23 MK 1 Equipment Case1 BN 2090 09 Balanced test adapter for complex impedance BN 4033 00 11 1 See MK 1 or MK 4 data sheets for details ...

Page 118: ...5 10 Ordering information SPM 32A SPM 36A 5 20 ...

Page 119: ...anced input 4 1 BANDW Hz 4 6 Bandwidths 4 39 Bargraph 4 56 BATT POWER 4 13 Battery power 3 3 BATTERY 4 13 BW 4 14 C CAL 3 10 4 8 4 13 Calibration 3 10 Changing the batteries 3 5 CHARGE 4 2 4 14 Charging the batteries 3 7 Coaxial input 4 1 D dBm0 4 5 4 54 Default setting 3 11 DEM LOWER SB 4 13 DEM UPPER SB 4 13 DEMOD 4 6 4 20 DF 4 26 DISPLAY 4 67 Display 4 11 Display averaging 4 58 Display contrast...

Page 120: ...rence 4 50 Level mode 4 46 LINE POWER 4 13 Low batteries 3 4 M MAX HOLD 4 6 4 13 4 59 Measured 5 5 Measured quantities 5 5 MEM OFF 4 10 MEMORY 4 60 MODE 4 5 O ON OFF 3 10 4 2 Operating modes 4 15 Operation 4 1 P PERM ON 3 11 4 2 4 14 POWER 4 2 Power level 4 25 4 48 Power supply 3 2 R RCL 4 64 RCL MEM 4 10 Recall setup 4 64 Receive frequency 4 26 REF 4 5 Reference level 4 50 REL 4 6 Relative levels...

Page 121: ...g the bandwidth 4 43 SPECIFICATIONS 5 1 SPM TEST 3 10 SSB demodulation 4 20 STEP 4 4 4 26 STO 4 14 4 62 STO MEM 4 10 Storing a setup 4 62 Storing results 4 63 Storing setups 4 60 Switching on 3 10 T t 4 12 TEST CONFIG 4 8 Threshold 4 32 TUNE 4 3 4 26 U up down keys 4 9 V Voltage levels 4 25 Voltage measurement 4 49 W WIDEBAND 4 14 Wideband measurements 4 18 Z Z W 4 8 ...

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