Introduction
Contents
1. GEN PLL Positive coupling Negative coupling Jogsall KC901S 0 05 3GHz 5 A mos PORT3 DDS raat S11 RF QUT 0 10 S0M 02 PORT2 Q A e a ASN AE SS amp X azma CX LOCAL1 PLI LOCALe sh Z HER 045 2GH 4 gm 45MHZ 44 9MH gt z frequency mixing amp ZS The second IF tl PORTL DA A Torah Detection S21 RF IN cael TF CARD b Application computer Data interface processing Display Phase demodulation Detection Chart 6 1 The Functional Block Diagram of KC901S When S11 is measured CW produced by signal source gets positive signal from positive splitter prior to getting negative signal from the bridge and finally it output from port 3 Phase difference and amplitude difference are got after the positive and negative signals enter two receivers separately via double conversion to phase demodulation and detection circuit Adopting counting method to do digital phase distinguishing KC901S measures amplitude with logarithmic detector All data about S11 is got from phase difference and amplitude difference When S21 is measured signal source still output from port 3 via the bridge but no detection is taken before it passes through DUT Next the signal inputs into port 1 to undergoing a frequency con2. Net weight of host lt 1 2kg Total weight 2 0kg Notes All indexes are measured in low speed mode and zero attenuation of output Some unusual data points may go beyond technical parameter chart 59
3. 3 1 Overview Normalization of KC901S ports has been finished before leaving factory therefore direct use is allowed in most cases The curve may deviate after power on in the field because of various reasons In common engineering applications it is not necessary to calibrate KC901S as long as the measuring result is helpful to analyze and solve problems Cables and a great number of connectors indispensable to measure cause insertion loss With time going by and the temperature changing performance of KC901S may drift All those disadvantages have negative impact on measurement the user can do calibration as occasion requires If conditions including cables and temperature change error may occur during calibration As a result it is better to make measuring conditions 23 the same with calibration conditions In other words calibration conditions should be as close to measuring conditions as possible 3 2 Calibration Modes There are three kinds of calibration modes factory calibration system calibration and user calibration Factory calibration high density calibrations of all frequency ranges have been done before KC901S leaves factory Calibration scaling algorithm operates a higher density interpolation After factory calibration basic errors can be corrected in any frequency so generally no calibration is needed Factory calibration data saved in KC901S can not be reset and directly used by the user Factory reset func
4. If necessary reset the CENT REF of the equipment and reduce span so that the new frequency curve can be partially enlarged Adjust the mark1 2 position more accurately At the meantime connect measuring cable with straight thread connector to go on with S21 through calibration Reconnect the output port of equipment to TX port of duplexer and then link the in port to ANT port finally connect the fictitious load to the RX port Next repeatedly adjust the three screws from middle to TX side to keep the mark minimum reading Normally the reading should exceed 70dB good quality duplexer can reach 90dB At this moment the S reading of Mark2 means the insertion loss of duplexer transmit signals 34 w KC901S f ME BD8AAA 49 62 7 54V 00 03 940 7hPa Stepping Sweep Bandwidth ow E cne 467 70000078 50 000000 a oio Jewe Local oscillation keeping Chart 4 2 Typical curve of LOW side of duplexer uncompensated cable loss Connect the output port of KC901S to ANT port o Then connect the fictitious load to the TX port Slightly adjust the three screws near the RX side to keep the mark2 minimum reading Normally the reading should be less than 70dB Read the S reading of markl which means the insertion loss of duplexer transmit signals Please switch local oscillation mode choosing the lowest way in the curve bottom Adopt different local oscillation modes when measuring both parts of the duplexer Sometimes the two s
5. RF circuit is closed and only CPU and display consume power When four batteries are installed the brightness of screen will be 20 and the temperature will be 15 C Chart 1 shows time of endurance High or low temperature and the low actual battery capacity reduce time of endurance Chart 1 Time of Endurance hours 55 Function capacit 2200mAh 2600mAh 3100mAh 3400mAh y S11 3 4 5 5 5 S21 Insertion 3 4 5 5 5 Loss SPEC FILED 5 6 7 8 RF SOURCE 5 6 7 8 AF SOURCE 6 8 10 12 STOP 12 15 19 21 If only two batteries are installed the discharge rate will be larger Thus time of endurance will less than the half of the time above 6 3 Technical parameters Frequency range Transmission measurement 100 KHz 3GHz Reflection measurement 250KHz 3GHz Output level typical value 3dBm or 2mW 1MHz 2GHz 0dBm 2 3GHz Variable attenuator 0O 30dB Input sensitivity superior to 107dBm or 1uV 300KHz 1GHz 56 superior to 87dBm or 10uV 1 2 2GHz Damaged level all the RF ports DCI5SV 20dBm Measuring range Of S21 typical value 110dB 1MHz 1GHz about 60dB in 1 OOKHz about 110dB in 435MHz 70dB 1 3GHz Resolution Frequency is 1Hz level is 0 1 dB phase is 0 01 Level uncertainty Typical value 25 C battery voltage gt 7 5V 1 5dB spectrum measurement REF 20dBm 3dB spectrum mode and fi
6. the effort Do not overtighten the connectors Standard load is a valuable accessory Careful using properly keeping and regular checking should be done Before calibration please check and clean the connectors to prevent damage from the load or from the 28 connectors of KC9OIS 3 6 Necessary Preparations 3 6 1Check up battery power before brings the apparatus on the go Start up KC901S to observe voltage If voltage gt 8 0V it means that the rest power is more than a half It is strongly advised to set auto power off in case that the battery runs out For long hour s outdoor work either a charger or a vehicle power supply connector should be used In wildness a external battery pack is needed 3 6 2 KC901S should be carried with a waterproof suitcase to prevent from rain and water The specialized suitcase for KC901S is advised 3 6 3 Proper attenuator should be prepared for measuring transmitter and amplifier When the measured signal exceeds the limit attenuator must be connected in series 3 6 4 When testing antenna in places with lots of antennas a terminal wattmeter is used to measure inductive power of the antenna which should not be more than 0 1W Many times several sets of antennas are concentrated on the same tower inducing strong transmit power through space coupling Too strong RF power induced from the antenna under measurement are bound to burn down the equipment 3 6 5 If short wave antennas are erected near hig
7. the equipment In addition neutron irradiation makes irreversible damage 51 10 The USB socket is fragile Use Soft data cables to avoid lateral force 11 Period of verification of KC901S is one year It is better to send it to manufacturer for calibration and verification 12 The warranty period for the host is one year Any exterior damage which is caused by normal wear and tear or artificial damage is not included in the quality warranty after delivery 12 It is forbidden to dismantle the case arbitrarily during warrant period Damage caused during the tear down is not included in the quality warranty Attempt to disassemble RF components can void the warranty 52 Chapter Six Technical Notes 6 1 Measuring Principle The measuring circuits of KC901S consist of one signal source and three receivers The signal source is divided into two frequency bands the one lower than 50MHz AF signal source lower than 50MHz is directly produced by DDS the other higher than 50MHz is produced by PLL The two frequency bands pass through one gating switch converging into one RF signal Two of the three receivers are relevant applying to S11 measurement while the other applies to measuring S21 and frequency spectrum
8. transmission line when connecting transmission line under test via patch cord The compensation of cable length in FUNC menu should be set as zero In Chart 4 5 electric length 1 432m cable length 1 005m It can be calculated that velocity factor is 0 7018 43 KC901S E BDSAAA 49 62 6 89 01 10 947 2hPa 555 6KHz Phase frequency Ss a OF wi 50 000000 MHZ Curve een BE Re catibrtio to keeping mode Chart 4 5 Measuring Electric Length in Phase Frequency Characteristic In short circuit and open circuit cable loss is about half of return loss When cable is connected with antenna return loss at non working frequency can be used to estimate cable loss 4 4 Spectrum Display KC901S strengthens properties of the input channel to provide the basic spectrum display Warning The input port of KC901S permits a limiting level of 20dBm and a limiting DC voltage 15V The apparatus is bound to get damaged if the standard is disobeyed When measuring transmitter and amplifier an appropriate attenuator must be concatenated to control the limiting values 44 Notes 20dBm is the limiting level not damaging the apparatus which does not mean that KC9OIS is able to measure the signal at 20dBm The proper level is less than 10dBm for the sake of accurate measurement KC901S is a network analyzer so the measuring result of spectrum is only for reference Mirror image interferes with th
9. user detects interference source in FIELD mode FIELD function is used to measure emission field strength around the antennas of radio station IF gain which may be damaged by strong signal because of wrong setting in SPEC function is manual set Connect a filter of narrow band pass in series to detect interference with FDM system of 45MHz frequency difference for fear that the local oscillation reveal interferes with communication system Warning Without permission do not use KC901S to monitor the spatial frequency spectrum of non working frequency It should not be revealed even it is measured by accident 48 Chapter Five Maintenance 5 1 How to Clean Screen Keyboard and Ports Please remove protective films from the screen The glass screen protector is replaceable so there is no necessary of pasting screen protector which could reduce visibility under the sun Please clean the dirty screen and keyboard with wet tissue firstly and with gauze later It is a proper way to sweep away the dust inside with 0 2MPa compressed air after dismantling the control circuit board On occasion the glass and rubber pad should be replaced RF connectors shall be frequently cleaned with dry swap first and with anhydrous alcoholic swap later End faces of core needles and ledges outside connectors are supposed to be wiped luminously Twisted tissue is a good tool to clean up the holes on core needles warning
10. E and audio frequency signal source AF SOURCE MODE is used to select function The equipment shifts between function menu and function selection menu by using MODE a couple of times In most cases MODE equal to HOME turns the screen back to the function menu or function selection menu so it is frequently used The typical application of Reflection Measurement S11 is measuring the standing wave of antenna The right port should be chosen Reflectometer is a kind of vector function with various display modes selected in FORMAT menu In Smith Chart and impedance display the second soft menu from the left provides more display modes Access press MODE and then select 11 _CFORMAT in the soft menu decides the display mode of measuring result The typical application of S21 is measuring amplitude frequency characteristics of filter or amplifier and gains of antenna The right RF port is to output signal and the left one is to input Access MODE and then press S21 Insertion Loss Measurement is a special type of transfer measurement characterized by high respond speed As a result it applies to the fine tuning of filter and measurement gains of antenna In order to keep consistence with the operating habits of ordinary receivers the entry into Insertion Lost Measurement is set in Field mode Access firstly MODE and then press FIELD finally press Insertion to make GEN ON appear The typical application of SPEC is monit
11. Introduction KC901S is a multimeter for radio frequency that supports both vector network analysis of one port and scalar network analysis of two ports With extensional functions of spectrum field strength and signal projector the maximum practicality has been got Main Features The frequency range is as high as 3GHz The Stepped frequency of entire domain is 1Hz Good accuracy and stability Double conversion and high anti interference ability Abundant functions and convenient to carry The fruits of wisdom of the community Main Functions Transmission measurement filter adjustment amplifier measurement and directivity measurement of antennas Reflection measurement adjusting impedance matching network and examining quality of antenna feed system Measurement of Low frequency signal source and radio frequency signal source Spectrum display and field strength detection inspecting radio station emission performances and searching for interference sources Recommended Appl ications KC901S is designed for adjusting RF circuits such as filter amplifier splitter combiner for testing input and output impedance evaluating the quality of antenna feed system and for detecting signal amplitudes of equipment at all levels In some bands field measurement and detection of interference are allowed When combined with community exchange KC901S is a good tool to learn radio frequency knowledge In the area of expertise i
12. SHIFT ENTER Locking the keyboard and knobs Chart 2 2 2 2 Measuring Ports There are three measuring ports in KC901S Two of them are external RF ports and the other is AF port The most right one is the output port of frequency sweep signal source The most left one is the input port of tracking receiver The other RF port inside has been connected to standard load that is replaceable wal He fE i i S11 RF GEN S21 SPEC S21 FIELD Riese Rotate Press Chart 2 4 The Top ports Referring to Chart 2 4 Port 1 Port 2 and Port 3 are from the left to the right The interfaces of N are precision so more attention should be paid to protecting these ports especially S11 in the most right Careful examination and repair are expected done before well made connectors are linked However it is useless to connect switch overs that reduces accuracy The ports are designed to be pulled and plugged for 500 times Replace them with new ones as soon as the life ends in case that vector measurement is affected 2 3 Auxiliary Ports There are three interfaces in the right as following Power input data interface and SD card interface chart 2 5 Micro SD card Micro USB EMR Power input ARRE H Ji i E Chart 2 5 The Right Interfaces 2 4 Function Description Six basic functions of KC901S reflection test S11 transfer test S21 spectral view SPEC filed intensity FILED RF signal source RF SOURC
13. The charger and batteries must be removed prior to dismantling circuit board The user actions of dismantling enclosure and circuit board to install batteries and of cleansing screen do not change the term of maintenance However any fault made during this process is not guaranteed 49 It is not allowed to cleanse screen keyboard and knobs with organic solvent 5 2 Other Matters Needing Attention 1 The equipment should be settled inside in a pack or a suitcase during the long distance transportation A baldric should be used while on the go to avoid falling off collision or putting together with other construction tools The connector must be removed during transportation and carrying unless necessary It is forbidden to use measuring cable as handle 2 Flexible cable should be used to switch while measuring heavy devices or connecting thick feeder 3 While installing the plug ins please point the position plug in carefully shake lightly and screw slowly Screw the thread tightly when feeling the core needle has been already inserted into the core hole Both hands should operate to screw the thread with one hand holding the body part of the plug ins to avoid revolve of the plugs another hand revolving the exterior helicoil Revolve of the whole plug should be avoided otherwise lifespan of the RF connector will be dramatically shortened and also cable will be damaged Pay attention to check before stalling plug ins at constructi
14. ching to the source adjust AMP based on the intensity or adopt the field mode Move in the direction of the strongest interference and keep approaching to the source Generally speaking the amplitude should be over 70dBu 37dBm when approaching to the source 46 h ji 4 he HY Got A N IAK ey Searching for testing po t bgo 043 4 Kae SW Choosing a high Wais s gt TEA M testing point Sse yy i tag2b X if Directional angle 22 B 6 A WI SPS A TP Ae AN hy frea CCN N PX 60 120 is best OM she Potential interferenc egg RARA amp 71849 SPN 4 ip 4 x Line of bearing 1 44 4 Nivo2 4 Chart 4 4 An example of cross location and diagramming method Connect a band pass filter between the equipment and antenna to the reliability of measurement In a helical structure or cavity structure band pass frequency of the filter can be adjusted under the supervision of KC901S before using When measuring weak signal it is practical to connect a low noise amplifier between the filter and the equipment Locating the interference source is a task combined with theory experience and technology no matter what kind of equipment is used Practices increase efficiency Because of diffraction and reflection of signal there are many illusory directions in measurements in cities and mountainous areas 47 For narrow band signal higher response speed is got when the
15. e spectrum mode Connect an appropriate filter to the input port in series to operate monitor function When measuring shortwave spectrum use _ Local Mode to identify image response Cascade KC9504 01 of 120MHz to eliminate interference from intermediate frequency feed through If the concerned span is too narrow set CENT and SPAN according to need Set AMP based on intensity of the signal under measurement AMP lt 40dBm when searching for weak signal Unless conditions permit scan piece by piece in narrow span 4 5 Detecting Interference Source In bands no interfered by mirror image use KC901S with directional antenna to detect interference source by oto method After entering spectrum mode set center at frequencies probably interfered Span is set at small value like 1MHz When interference is weak REF should be set to 60dBm Do not stop Adjusting direction of 45 antenna and polarization mode to detect interference signal until the most obvious bulge emerges in the center of spectra After measuring the directional azimuth angle of antenna by magnetic compass trace out directional line In the same way get another line at another point The intersection point of two lines is likely to be where the source locates Preserve an angle of 60 120 close to 60 between the linking line of two measuring points and one directional line Chart 4 4 Keep the measuring point in height to avoid being blocked by buildings When approa
16. eld mode 0 3 0 05L dB in S21 measurement when calibration is directly connected and insertion loss L lt 60dB 0 05dB zero adjustment drift of insertion loss mode 5 min warm up every hour 1dB 3dB loss SOL calibration 3dB lt RL lt 25dB Absolute directionality typical value inferior to about 90 interval superior to little interval 18dB 3MHz 15MHz 2GHz 3GHz 20dB 15MHz 2GHz 57 Relative directionality When SOL calibration is done and directivity of calibrating device is superior to 48dB 45dB 3MHz 2 5GHz 25dB 1MHz 3MHz 2 5GHz 3GHz 20dB 300KHz 1MHz Phase uncertainty 1min warm up continuous mode 2 3MHz 1GHz 5 1GHz 2 5GHz 1MHz 3MHz 8 2 5GHz 3GHz 300KHz 1MHz Internal bridge directionality typical value 18dB 3MHz 15MHz 1 5GHz 3GHz 30dB 15MHz 1 5GHz Frequency stability 1ppm year 25 C Supply voltage 11 5V 32V external power 7 2 8 4V battery 105V 230V 50 60Hz power adapter input Battery endurance typical value 25 C 7hours spectrum field signal source Shours S21 or S11 includes insertion loss test 20hours in STOP mode Screen brightness is 10 Humiture range 58 40 65 C external power source depends on temperature characteristics of battery when power is on no condensation and no frosting Size 200x114x46mm length width height weight including battery
17. for one cable it should be bridged over the two ports before measurement Chart3 1A As for two cables them should be connected 25 with a connector with good quality and bridged over the two ports Chart 3 1B KC901S Chart 3 1B Connection of Two Cables If many series cables in different locations appear in on system a one time series calibration is suitable When testing power amplifier connect an attenuator with the output port in series to avoid damage If it is a little signal amplifier connecting an attenuator with the input port in series is imperative to avoid strong signal Before that kind of measurement it is suggested that all the attenuators should be connected with cables in series to operate calibration 26 Follow the hints of Re CAL in function menu to start user calibration If frequency is changed after calibration the system calibration parameters are automatically used 3 4 Calibration before 11 Measurement Although there are many display modes in S11 function only one calibration is necessary because the same data is being shared in all modes It is necessary to operate user calibration in these following cases 1 In acceptance measurements for important antennas for example antennas of radio and TV emission stations 2 Failing to be connected to KC901S the port under measurement should be linked with extra cable After calibration please check whether the curve
18. h voltage lines and sub stations measurement induced voltage not more than 15V with 29 multimeter Alternating Current It is strongly suggested that the shield of coaxial line should be grounded nearby 3 6 6 If RF signal of circuit board is measured by a probe outside protective shield of measuring cable should be connected with ground of the circuit It is dangerous to do suspension measurement that may burn out KC901S and board under measurement 3 6 7 KC9O1S can be used during charging but measuring active devices should be avoided If the measurement is inevitable an equipotential bonding between ground of KC901S and ground of DUT is needed to avoid damage from DUT and the equipment 3 6 8 The standard strap is only suitable for general use Firm safety rope and packing bag should be prepared for working in height to avoid accidental falling Set a warning region below the tower when someone works on it 30 Chapter Four Common Measurement Methods 4 1 Quick Adjustment of Diplexer A duplexer is an important part of a repeater The insertion loss and isolation ratio of a duplexer are directly relative to the overall function of a repeater KC901S can provide an isolation of exceeding 100db operation range under regular VHF UHF frequency band conditions and a duplexer can be adjusted at its optimate state under the supervision of KC9OIS Prepared accessories for usage A fictitious load 50Q 2 RF Cables and necessary RF c
19. he adjustments to keep the 36 reading data stable Notes Port match has influence on the rejection characteristics Measuring results are influenced by the type of apparatus used and the relationship between the equipment changed and ports of the deplexor The antenna impedance changes as repeater is different so practical performance falls behind expectation Draw lessons from practical performance after installing repeater in the first adjustment Connect in tandem an attenuator around 10dB in the input port to improve the match Increase output attenuation SHIFT Po ATT to 10 or 20dB which is helpful to reduce influences on measuring results by non linearity 4 2 ANT Measurement Warning It is possible for the output port of KC901S to a maximal outputs 10dBm 10mW KC901S transmits the output into the air in ANT measurement Po ATT increased can reduce emission but Re CAL should be done 4 2 1 SWR Measurement for ANT When ANT is to be measured the equipment should be adjusted to S11 mode and Format is VSWR Settle down center and span the operator should be away from ANT 37 The SW of AN is easy to be affected by the surround environment So it is better to choose a wide outdoor field such as a rooftop The length of the feeder should be as short as possible disconnect the feeder from the end which connects the ANT Contain the feeder for calibration 4 2 2 Cable Deduction In meas
20. ides reading data of duplexer affect with each other so it is necessary to adjust the three crews repeatedly until the restrain 35 reading data reach or exceed 70dB Do not adjust the restrain curve of the duplexer into a too sharp shape Reduce SPAN to 1MHz observe the bottom of the curve the width should exceed 100 KHz If the curve is too sharp the cusp of the curve may move out the used frequency while the temperature or the match condition of ANT is changing If there is a contradiction between insertion loss and attenuation attenuation on the RX side should be primarily guaranteed Appropriately turn down the transmit power so that to reduce the requirement for attenuation This should be abided by the principle of Adjust TX toward inside and Adjust RX toward outside try to keep balance of insertion loss For the duplexer whose coupling degree can be adjusted by screw adjust the coupling screws If all adjustable screws are not long enough change them to long screws If the entering length of screws is too long the Q data of duplexer will be lowered Dismantle the extended solenoid of the duplexer in case of emergency If the insertion loss can not be turned down S11 measurement can be tried connect the fictitious load to the non tested port rather than to the in port of the apparatus Tentatively adjust and compare the reading with others try to control the SWR under 1 5dB Please screw and fix the screws during t
21. justed to an appropriate length the user should sling over it or wearing it straightly If KC901S is used in movement it is suggested that the user hangs it upside down The strap should be shorten and slung over shoulder when running with it and prevent injury to the body KC901S is designed to be held with left hand and be handling with right hand When standing to operate the user holds the left hand at the upper left thumbs the knob and places the bottom against the stomach At the same time the user connects cables and plays keyboard with the right hand The knob is not necessary because keyboard offers all the functions _ equal to rotating knob and ENTER means pressing the knob The user holds the bottom of liquid crystal with both hands and plays the keyboard with thumbs Fix KC901S in the workbench with screws through mounting points Chapter Two Quick Guide Designers have tried their best to make users understand easily Users who have some basic knowledge can handle it in a short time Therefore this manual does not demonstrate every detail as usual but only explains some points that are special 2 1 Power Switch and Keyboard Chart 2 1 shows keyboard functional layout of KC901S Press POWER at the bottom left for 0 5 second to start up or shut down After the boot the test mode showing and the main setting are consistent with the settings that were used last time The menu displays items related
22. llels and two series The power management circuit has the functions of overcharge protection over discharge protection balance protection and short circuit protection The battery compartments are appropriate for cylindric lithium batteries with a diameter of 18mm and a length of 65mm also known as 18650 cell The batteries must meet the industry demands Although KC901S works on two or four batteries four batteries are preferred The rated charging current of KC901S is 1A If two batteries are put in for a single battery the peak charging current is 1 2A and the peak discharging current is 1 5A If four batteries are put in the current will be a little higher than half of that The batteries must be the same type and simultaneously produced Before 6 they are put in the voltage of every battery should be basically the same and the difference is not higher than 50mV Otherwise the batteries should be equalizing charged or discharged prior to using The usage of batteries should be based on the instruction General speaking low temperature resistant batteries are used in winter When the ambient temperature is over 45 C the battery temperature will be higher than 65 C due to the heat produced by the circuit Therefore it is necessary to choose high temperature resistant batteries 1 2 How to Install Batteries Tools needed a hexagon screwdriver with the diameter of 2mm Step 1 put KC901S flatwise in the workbench and take d
23. ng in S21 mode Referential antenna Measured antenna or the standard antenna forty ct iS Rotatery control cable Antenna supporter KC901S a Bo angle indicator Chart 4 3 Antenna gain measurement in an open area In the measurement press SHIFT 1 to save data to analyze afterwards In order to decrease operation complexity KC901S automatically names files in chronological order The user can make notes of starting time and quantity to avoid confusion If the user wants to measure the antenna gain it is necessary to install the known antenna gain antenna for reference unto the to be measured antenna supporters adjust the orientations of the referential antenna and testing antenna make the referential antenna s given direction aim at the measuring antenna then go on user calibration under S21 mode Then 41 keep the settled reading of the equipment invariant and then change the referential antenna into the to be measured antenna to measure write down the reading of different angle S reading At this time the obtained reading plus the referential antenna gain this is the antenna gain of different angles If many frequencies direction graphs and antenna gains should be measured repeat the above steps by changing the different frequencies During measurement do not change frequency otherwise user calibration loses efficacy and the data lose its relative significance While measuring the
24. of background noise differs in modes the priority is the lower one Local oscillation mode is ineffective below 1OOMHz Notes Factory calibrations of SPEC S21 FIELD are operated under the high local oscillation mode Under the low oscillation mode a small measuring error May Occur 2 8 Filed Strength Mode Setting The actual measurement is the level of input port By inputting the electrical level and calculating antenna factor the field value will be got Antenna factor is mainly relevant with frequency and antenna gain The equipment should get the antenna gain in order to know the accurate reading of field After enter the FIELD mode the user should press ANT GAIN on the 20 right side Firstly Select and then input the antenna gain on numeric keyboard The item in the middle decides the refresh time of reading in levels of FAST MIDDLE and SLOW MIDDLE is recommended The refresh time of Table S not disturbed by the setting is used to observe instantaneous changes of signal intensity Warning KC901S is a network analyzer which does not prevent the reveal of local oscillation When it is used to observe spatial frequency spectrum and field strength local oscillation signal will flow backwards to receiving antenna The strength may arrive 10dBm and the frequency will be 45MHz higher or lower as the receiving frequency Consider consequences are caused by the sending signal and
25. of short wave it is allowable to appropriately decrease the distance between the two antenna supporters If necessary take more times of tests by changing the distance and take the average number to eliminate the impacts cause by ground reflection According to the distance between the two antenna supporters prepare long enough cables try to keep the equipment and tester a distance more than 10 times of wavelength form antenna Besides to be tested antenna prepare another known antenna gain antenna for reference Method Install measuring antenna and to be measured antenna on the supporters Chart 4 3 At first make certain direction of to be measured antenna predict the main flap direction or mark a direction aim at the measuring antenna then set the apparatus S21mode and input measuring frequency Normally choose the smaller span such as 1MHz Furthermore calibrate the apparatus turn the curve sheet into zero Next rotate the to be measured antenna with a certain angle at intervals Write down S reading dB number At last draw dots on the angle antenna 40 gain graph thus to obtain the direction graph of the to be measured antenna The above measurement can also be done by utilizing insertion loss measurement mode At first set FIELD mode select Insertion to start insertion loss measurement then press Auto CAL button to turn the insertion loss reading into zero The insertion loss reading means the same as the S readi
26. on If the core needle protrudes too long curve or lant stalling should be done after repair of the core needle otherwise the interface will be stretched 50 4 The equipment should be avoided of being exposed in the rain or water inflow The equipment should be put inside the suitcase or be prevented from rain in rainy days Turn the power off immediately if clean water flows in fling out the water though the bottom part and blow dry it ina ventilated place Waterproof suitcase is suggested to be equipped if the equipment is often in the open air 5 The equipment should be sealed with plastic bag if the operator enters in a room with central heating from the outside in winter If there is dew formation on the apparatus firstly KC901S should be put near the radiator to be dried and then the equipment can be powered on But it is necessary to pay attention to the temperature 6 It is no good for maintaining good battery life if power shortage warming appears or power off A long term floating is banned When the charger is connected for a long time in work batteries should be removed 7 When KC90I1S lies idle the battery should be 8 0V for storage During that time it is better to annually charge once at least to 8 0V It is suggested to remove batteries before a long term storage 8 Do not keep the equipment close to high powered transmitting antenna Do not kept interphone close to transmission 9 Ionizing radiation may do harm to
27. onnector assembly It is preferred to fix KC901S on the workbench Adjustment tools socket wrench with center hole screwdriver Fix the be adjusted diplexer on the workbench if possible Special setting employ intermediate speed or high speed FUNC 31 Speed in initial adjustment Employ low speed or insertion loss mode in precise adjustment of notch points Here is an introduction of adjustment steps by taking six cavity duplexer as an example that works on the principle of notch filter Adjust the KC901S to S21 mode and adjust the center and span of the apparatus so that frequency band can cover the original frequency and new frequency of duplexer The AMP can be adjusted to OdB or 10dB change the AMP and ordinate span according to the position of curve When the ordinate span reaching 20dB div Then start system calibration Move mark and mark 2 respectively to near the new receiver frequency and transmitter frequency Please use the equipment to measure the insertion loss S21 RF cable first then sway connection cable and connector lightly to look at if the curve dithers while measuring in order to make sure there is no poor contact The insertion loss of cable should be as small as possible The quality of cable should be good enough to provide with excellent screen Hang cables in the air to observe the position of noise floor for a minimum of 90dB at 450MHz Clean the socket of the duplexer then connect the outpu
28. oring the occupancy and the interference of band and adjusting circuits producing RF signals except 45 MHz KCSA R100 is connected to find unidentified emission source Access MODE and then press _ SPEC FIELD applies to not only measurement field strength coverage but also searching the amplitude of RF The port of KC90IS is capable of DC isolation so as to externally connect probes to directly search the signal value of receiver and transmitter It is necessary to match impedance and concatenate attenuator when detecting transmitter As long as experiences are got FIELD is used to detect emission the radio station to find fault in time Access MODE and then press FIELD RF SOURCE produces a millwatts signal with an application of transmitting weak signals to the air to determine the sensibility of radio station from a close distance particularly the sensibility of relay station It is handier to use the small signal for experienced users More externally connected attenuators further develop the applications of signal source To some extent RF Source can adjust the signal level with the help of built in attenuator The output attenuator plays the role as an amplitude modulator to carry out ASK If the output attenuator has been applied to adjusting output range the used decrement which has been used is unable to modulate As a result the modulation degree conflicts with the output attenuation When output attenuation increases the mod
29. own the two screws from the tail Chart1 1 Chart 1 1 Step 1 Step 2 Pull the chassis from keyboard to tail for 2cm Chart 1 2 Hold two sides of the upper chassis with fingers and meanwhile pull the RF joints It is a good idea to knock the tail in the lower chassis when difficulty occurs Do not overexert and pull less than 4cm in case of the fracture of interior cables WwW Chart 1 2 Step 2 Step 3 Slightly uplift the cover and then turn the left Step 4 Install batteries The positive poles direct toward RF connector If only two batteries are installed please put them the left most side and the right most side Chart 1 3 Step 5 check the cable plug and any deviation is not allowed Step 6 Close the chassis in reverse order Press POWER to check If nothing unusual occurs twist screws 1 3 How to Mount Shoulder Strap There are mounting points in the tail and in the top so mounting in the both sides are allowed If the user needs to use KC901S when carrying mounting the strap in the tail is preferred Unwind the strap and remove it from the plastic fasteners thread it through the mounting points and lock in the plastic fasteners Us Chart 1 3 Battery Installment Warning The standard strap is appropriate in usual occasions Extra preventing falling measures should be taken when working at heights like towers or ladders 1 4 How to carry and hold After the strap is ad
30. s are in the proper position in the open circuit and loading In VSWR mode the curve should be higher than 10 in open circuits and it should be lower than 1 2 with standard load of 50 Ohms with good quality Notes In the far end calibration of external cable if electric length of the external cable is longer than the half of STEP wavelength scan points should be increased or SPAN should be reduced before calibration For example 3MHz stepping equals to 100m wavelength and the external 27 cable is not longer than 35m electric length the actual cable length speed factor Select Re CAL under S11 mode and follow the steps given 3 5 Reflection Standard Implements S11 adopts SOL calibration so three standard implements are needed Short Open and fictitious load During the calibration these three are considered ideal KC901S looks for distinctions between ideal value and actual value describing all errors with equations Therefore the three standard implements should be as close to ideal conditions as possible KC951011 KC951012 is a commonly used standard implement offered by Kexinshe Users can choose other proper standard implements being aware that the terminal effect should be small because of no compensation provided by KC901S The nominal electric length of KC951011 12 is zero Type the actual electric length in FUNC if you want to use the offset calibrator Connect the standard load to the equipment with all
31. t can be applied in professional Communication Engineering antenna manufacture and daily maintenance of broadcast and TV radiating stations promoting working efficiency ease carrying burden as well as improve quality of works Acceptance and Check When receive the product it is necessary to confirm the integrity of package First step is to read introduction of user manual and check the equipment A standard packing includes KC901S 1 Charger 1 Strap 1 User manual 1 Check up all items and make sure of no damaged appearance Examine whether screws of KC901S loose and unusual sound heard when shaking Without any exceptional cases the charger should be connected before starting up If the battery is installed press POWER for 0 5 second for start up inspection Safety Notes KC901S is not a kind of consumer goods so the users should be professionals or be acquainted with professional knowledge of this field In this user manual Notice indicates inaccurate measuring results or ordinary risks Warning indicates possible personal injuries serious risks equipment damage or other serious consequences Warning When water intake unusual sound or other obvious abnormal is observed do not start it up During thunderstorms it must not be used to measure any outdoor equipment including that with lightning arrestor Pay attention to grounding of DUT to prevent electric shock Eq
32. t port of KC901S to the TX in port of duplexer usually marked high next connect the in port of the apparatus to the ANT antenna port and connect the fictitious load to the RX output port usually marked 32 low chart 13 Fictitious Load _ _ er KC901S TX ANT R X Le Le Le Le Le HIGH LOW cent sean t 3 MARK ANMP 4 Ls Ls bbs kechuang org O Chart 4 1 Example for Connection Method of Duplexer Measurement Adjust the three screws near the TX port to move the trough to mark1 indicated position until they overlap Then take turns to slightly adjust screws under the supervision of S indication until the reading is the minimum the maximum negative Normally the reading should reach or exceed 60dB At this moment mark means the HIGH isolation ratio and mark2 means the HIGH insertion loss 33 Connect the output port of KC901S to ANT port of duplexer still connect the in port to the RX port and connect the fictitious load to the TX port Adjust the three screws near the RX port to move the trough to mark2 indicated position until they overlap smoothly Then repeatedly adjust the three screws from center to RX side until the mark2 indication is the minimum the maximum negative Normally the reading should reach 60dB
33. take some measures for protection Always switch unit off or press stop to prevent other systems from RFI when you have finished measurements 2 9 Insertion Loss Mode Insertion loss is the system of single frequency point of S21 It is an essential measurement of S21 whereas only a single point frequency is measured After entering the FIELD test mode Insertion on the right of the menu means starting signal input Get to GEN ON into the display of insertion 21 loss measurement On the left of the screen the user will see that the reading is still an absolute level value While on the right it has been relative value Connecting the RF port with measuring cable the user selects AUTO CAL to adjust the relative level value into zero Next the user links testing cable to the measured device Now the reading on the right side is the value of insertion loss 2 10 Data Storage Plug in SD card to save data In measuring function press SHIFT 1 to save current screen capture Save measuring results and settings in numerical table When the computer is connected with USB cable KC901S will be a virtual USB flash stick Under such a circumstance the computer takes over SD card therefore data could not be saved when the computer is connected Under S11 mode S1P format file as well as all original measuring points should be stored on smith chart mode 22 Chapter Three User Calibration and Preparations before Measurement
34. tion sends the data to system calibration System calibration The same density with factory calibration but it allows self operation by the user Factory reset leads to system calibration data being covered by factory calibration data User calibration calibration can be operated by the user at any time This calibration whose accuracy is higher than that of factory calibration and system calibration corrects every data point without interpolation error User calibration only takes effect on set frequency If setting parameters are changed the calibration data will make no sense The final calibration data will be temporarily saved and the data takes effect back to the final setting parameters 24 Calibration Operation Under any display mode of functions of S11 and S21 CAL Select in the rightmost of the menu is used to switch among system calibration user calibration and closed calibration Re select RE CAL to operate user calibration if necessary Press SHIFT 7 into system calibration in FUNC menu KC901S prompts operational approach in calibration mode 3 3 Calibration before S21 Measurement If DUT is small and light one of the ports can be directly linked to the equipment although it is not a good habit On that occasion one more cable constitutes measuring system If DUT is big or the connectors do not match each other two RF cables are used Chart 3 1A Connection with one cable As
35. ts still exit We are willing to take your suggestions To the full extent of the law Kexinshe is not responsible for the loss beyond the prize of KC901S under any circumstances We take no responsibility for any indirect loss and losses in terms of time business inconvenience profit and abuse Maintenance replacement or returning product and refund are the only remedial measures we can take Kexinshe only take responsibility for the product within the guarantee period Under any circumstances we do not guarantee its applicability reliability and security for purposes of commerce industry and military We do not admit any promise made by dealers Please read technical instruction xx Support communities bbs kechuang org hellocq net ek Informal function The lasted version can be downloaded in measall com Chapter One Installation Guide KC901S does not have installed batteries when it leaves the factory The battery will be installed either by the dealer or by the user Before the battery is installed please supply power with power adapter and begin start up inspection If KC901S functions are all normal shut it down and pull out the power adapter and then install batteries 1 1 How to choose batteries Lithium ion batteries apply to KC901S For a single battery the charging cut off voltage is 4 2V and the discharging cut off voltage is 2 6V With the voltage rating of 3 6 3 7V batteries are connected in two para
36. uipotential touching is necessary before connection to avoid unequal potential damages to the apparatus and DUT Charging must be under surveillance It must be far away from inflammables and explosives when working or charging Do not cover the equipment or charger Take notice of the temperature range of storage and usage Do not place it in the vehicle under sun exposure KC901S must not be used for any illegal purposes People with intrusive electronic equipment should use it with caution It is better to avoid using it in hospitals airports and other sensitive positions KC901S must be carried with when the user takes a plane Make sure that the antenna is taken off field mode is set and power is off Please obey the local laws and any specific rules in the airport The maximum battery capacity of KC901S is 60Wh It is necessary to choose qualified batteries and to be careful of the risk of lithium battery Please place it out of the reach of children When KC901S is lent the user should urge the borrower to read user manual and inform the borrower of safety notes Important Statement KC901S is not a commercialized product that meets the demands for appearance and details of all users The manufacturing technical indexes and the third party certification affirm the designing and manufacturing capability rather than provide any guarantee for users Even though we have done our best to make it practical convenient and useful defec
37. ulation degree that can be used reduces Access Press MODE to select NEXT and then press RF SOURCE in menu AF SOURCE produces a low frequency signal with a typical function of adjusting the voice grade channel of electronic equipment Because AF SOURCE with various modulation modes produces the firm output of 50MHZz it is used to adjust RF circuits under 50MHz In actual AF SOURCE can be set in a high frequency but does not guarantee indices With the help of its harmonic wave it can be used to debug the sensitivity of radio stations Access Press MODE and then select AF SOURCE in menu 2 6 Local Oscillation Mode The Local oscillation in SPEC 21 and FIELD is used to judge mirror effects Low Lo low local oscillation If local oscillating frequency is lower than the measured frequency mirror image jam is caused by the lower frequency High Lo high local oscillation If local oscillating frequency is higher mirror image jam will be caused by the higher one If a signal appears in the same position whatever the local oscillating mode is it is likely to be there already If it disappears in any mode it must be false Appearing on the low Lo while disappearing on the high Lo the signal frequency is determined by subtracting 90MHz from the appearing frequency Appearing on the high Lo while disappearing on the low Lo the signal frequency is determined by adding the appearing frequency and 90MHz up If the height
38. uring antenna occasionally calibration can not be done on the port of antenna so the influence from feeders can not be automatically dispelled On this occasion reflection parameters of antenna send the condition of cable to KC901S the equipment deduces cables In FUNC menu there are two set items cable electric length and cable attenuation Cable electric length Cable length velocity factor Cable attenuation is estimated based on the attenuation at unit length presented in technical manual and cable length The two items above are both single pass parameters Cable deduction is employed in low frequency under 30MHz If conditions permit operate user calibration on cable s far side because the equipment can eliminate the influence of cable 4 2 3 Antenna Impedance Measurement KC901S works out the impedance of antenna by measuring amplitude difference and phase difference of incidence signal and reflection signal Because both amplitude difference and phase difference are related to feeder Operate user calibration in the feeder s far side unless antenna 38 is directly connected with the equipment The impedance is greatly affected by installation of antenna During measurement make the installation condition get as close to operating environment as possible For antennas installed in interphones and routers shells should be contained during measurement Antenna of router should be measured together with the mainframe Firstl
39. user keeps away from the antenna if it is necessary to rotate to be measured antenna manually After rotation the user should walk away from the antenna and then read the reading data Use two KC901Ss setting one signal mode another one FIELD mode this helps to build a single frequency point scalar net measurement system used in the setting of 2 far distant antennas Of course the one KC901S for transmit can be replaced by a transmitter of good stability If broader measurement range is needed in other S21 measurements two KC901Ss can be controlled by one computer 4 3 Measuring Electric Length of Transmission Line KC901S precisely measures the electric length of transmission line terminal in short circuit or open circuit In S11 mode take a smooth and periodic part of curve to measure frequency difference A of a circle of 42 phase shifting in PHASE display The electric length AA 2 Certainly the electric length AA phase shifting of 180 4 Additionally the electric length can be got from the frequency difference of double 360 phase shifting Besides deal with the derivatives based on the stored data on computer to get group delay In this way electric length will be calculated Take narrower SPAN or more scan points to avoid phase aliasing Take SPAN as narrow as possible to make the curve experience one or two periods in order to get a higher range resolution It is necessary to operate user calibration on the edge of
40. version and an IF amplification The absolute value of level is got via amplitude wave detector The result of transmission measurement is got after a comparison between testing data and calibration data transmission data recorded by KC901S In AF SOURCE function DDS is directly used to output AF signal KC901S adopts digital synthesizer with clock frequency of 400MHz so AF SOURCE function is able to generate signal over 50MHz and supports FM with guaranteeing index 54 6 2 Charging Time and Time of Endurance The rated charging current of the batteries is 1A The battery capacity determines charging time A commercial battery with the maximum capacity of 3 4Ah the charging time will be 4 2x3 4 7h if all four batteries are installed If two batteries are with a capacity of 2 2Ahm the charging time will be 2 5h KC901S automatically stops charging once the signal voltage is 4 2V and the total voltage is 8 4V When the temperature is either too high or too low the charging rate will lower down KC901S time of endurance is determined by battery capacity and function operating For different functions the electricity consumption varies itself Under S11 or S21 mode signal source and many receivers should be started so the electricity consumption reaches its highest peak Under SPEC FILED and SOURCE modes only signal source and one receiver should be started so the electricity consumption is lower When KC901S is in STOP the whole
41. with the current mode SPAN MODE FUNC SAVE READ 1 Po AlTT BEEP 3 SHIFT Chart 2 1 The Keyboard Keyboard s Functions at Level One Chart 2 1 Keys Functions CENT Setting scan central frequency SPAN Setting scan width frequency span MODE Entering function selection menu Repeated pressing means shift between function selection menu and function menu FUNC Entering system setup and exiting system setup STOP RUN Stopping scanning and starting scanning A Equal of rotating knobs with larger stepper MARK Entering the cursor function menu AMP Adjusting reference level trajectory position and range at signal source function POWER Power shift SHIFT Starting functions at level two Chart 2 1 Keyboard s Functions at Level Two Chart 2 2 Keystroke Functions Combinations SHIFT CENT Setting starting frequency SHIFT SPAN Setting stopping frequency SHIFT LOCAL Disconnecting from the computer and forcibly switching to the local operating system SHIFT FUNC Resetting to defaults SHIFT STOP R Switching to single scan Under this circumstance each UN pressing on STOP RUN means scanning once SHIFT 1 Saving data into the memory card SHIFT 2 Reading curves and settings from the memory card SHIFT 4 Adjusting screen brightness SHIFT 5 Adjusting RF output amplitude SHIFT 6 Key notification tone on off
42. y the original cable is cut from inside of router Secondly add a measuring cable for the antenna Thirdly the side close to antenna passes through magnetic ring For example measuring in calibration these parts of cables should be contained At low frequency if cable is not included in calibration set cable s electric length to deduce its influence At high frequency for example 2400MHzZz it is not a reliable solution 4 2 4 Measurement for Antenna Gain and Antenna Pattern Utilizing the function of S21 or insertion loss of KC901S together with another set of antenna to obtain the horizontal antenna pattern or back ration If there is another set of known antenna gain antenna then the antenna gain can be measured Measuring environment black rooms or standard measuring locations A level open area the size should be larger than 20 times of the wavelength For the antenna of over UHF frequency range smooth and level rooftop can also be the measuring environment 39 Equipments 2 antenna supports one has a rotary table if the condition is limited rotate the antenna support manually The height of the antenna supporters should suit to the designed usage conditions of antenna By principle the height should be longer than the 2 times of working wavelength It is better if the distance between the two antenna supports is larger than 10 times of the working wavelength For example the very long working wavelength of antennas
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