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4nec2 loading coil

4nec2 loading coil

With their Beta MCU 2. There is also a largely ignored current "bulge" inside a loading coil that affects losses in the coil. The retaining rings are shown against the bucket walls. The accepted method of spreading the weight is achieved by laying heavy dunnage in 2 or 3 lines under each row of coils, the coils being loaded, starting from an end bulkhead, in continuous rows right across the hold – wing to wing. Once settling on 4NEC2 as the modeling software, I started fiddling with the new antenna itself. 37, 01-03-2016 you can now get up to 15 watts output. Autotransformer type In an autotransformer, two coils on a ferrite rod can be used as a balun by winding the individual I did not have enough wire in my junk box to create a 68 uH coil. As of this day of August 24 th, Hi-Q-Antennas (Hi-Q-MilitaryAntennas) are again in full control of Manufacturing, Marketing of ALL of the Hi-Q antenna products. 4nec2. As the current is highest before the loading coils I would assume that the loading coils should be in the top of the antenna. The term originated in the 19th century for inductors used to prevent signal distortion in long-distance telegraph transmission cables. The term originated in the 19th century for inductors used to prevent signal distortion in long-distance telegraph transmission cables. By short, I mean 160-meter antennas up to about 60 feet in height to the loading coil. Customer Benefits Our solution for coil loading and storage A loading coil is a device placed along a circuit in a telephone line that compensates for the losses in signal over long distances. . EZ 121’ 76’ 46’ 50 pF 120 pF 11’ high 16’ high 68 uH Antenna design calculators is a curation of 82 resources about , Magnetic Loop Excel sheet, Parallel Square Conductor Transmission Line Calculator, Vertical Antenna Calculator, Analysis Of Antenna Mast Strength and Bending Stress, Full Wave Loop Antenna Calculator. Any reuse or redistribution of the contents of this website are strictly forbidden without authorization from MFJ Enterprises, Inc. The coil-loaded wire antenna is numerically analyzed and the good . launch 4NEC2 and load the file from step 2. Assuming a practical limitation on how large one can make the capacitance structure above the coil, there is a restriction on the loading-coil loss. EZNEC, winNECPlus, 4nec2, FEKO, WIPL-D, Zeland IE3D Finite element method (FEM) ¾Best for design of small antennas of complex structure ¾Ansoft HFSS Finite difference time-domain method (FDTD) ¾Time-domain method ¾Best for design of small antennas for broadband applications ¾CST Microwave Studio, Zeland Fidelity, Faustus MEFiSTo Wolf River coils have been scientifically studied through more than 100 WSPR studies, all relative to a reference antenna for controlled comparisons. NEC lets us model reactive loads. If we decided to pump 1500 watts into this system, approximately 150 watts will be dissipated in the loading coil. that of the EFHW antenna system (whip, coil, reactance and source). The 40M coil is shown in Figure 4 and the 80M coil is shown in Figure 5. The capacitor C (nominal value 400 pF; effective capacitance ≈ 478 pF at 3. 40 m Loading coil 20 m ¼ W with top hat Capacity Loading (top hat) A ¼ wavelength trans-mission line X velocity factor is a resonant circuit which creates a phase shift at which the open end decouples that frequency from the main element 10 m ¼ W VERTICALS ¼ W Decoupling Stub Multiband A A B B C A C ½ W ½ W VHF/UHF Collinear (J-Pole Match Moved Permanently. They often have extremely low capacitance at one end, and this makes stray capacitance throughout the inductor a concern. 1. file: 160m80m_broadband_dipole. The design elements of a 160m Half sloper are very simple. My Plate Tank Coil Details: Both of my coils for the 6AG7 amplifier are wound on National XR-5 five prong coil forms. Degrees of Antenna Occupied by a Loading Coil Cecil Moore, W5DXP, Rev. This agreed with my "unscientific" experience, when I fried the loading coil with 600W into Hustler resonator, melting heat-shrink tubing and wire at the bottom of the coil. Please make all Sales and Warranty request direct to: sales@hiqantennas. That "bulge" can cause the loading coil to have the highest standing wave current in the system. It is simply a half wave end-fed on 80m which will resonate on all multiples of that frequency, loaded with a small inductance near the feed end. net/4nec2/) ANTENNA MODELING BASICS EZNEC perfect, or real ground • Loads- lumped impedance (i. This article is intended to provide a use-ful interpretive model for understanding how antennas operate. A close-up of the antenna with all four coils installed is shown in Figure 6. I would like to base load it for use on 80, 160, and 600m. 8 MHz (e. NEC based antenna modeler and optimizer. Coil-Shortened Dipole Antenna Calculator. Center-loading (i. Current baluns, especially 1:1 ratio baluns, tolerate load impedance and balance variations much better than voltage baluns. Measured on my Byrd, I am getting between 16 and 18 watts output depending on the b Abstract. 4nec2 Simulator. Coil-Shortened Vertical Antenna Calculator. 5m. Figuring out the self capacitance of the choke coil took a little research. nec format) is shown below in Table 1 . 80 M . 3. A coil inductance formula is based on the basic loop inductance. There are not any antennas sold with inductance coils at their ends. Loading definition is - a cargo, weight, or stress placed on something. ON4AA’s 80, 40, 20, 15, 12 & 10m CL-OCFD. Steel Coil Calculators. Which is hardly true, to be non-scientific, just by looking at the wire in space. A 4nec2 Model for a Linked Inverted V Dipole. Stray capacitance from turn-to-turn increases circulating currents. Compare Products . Research has been done in various installation environments and antenna configurations, including some against competitor's products, to evalute for propagation effectiveness. Now let me stop for a second and mention that I am painting with a very broad I started with some simple modeling in 4NEC2. Below you will find a useful and easy to use online tool for calculating the Coil Weight, Maximum Coil OD, and Coil Lineal Feet. I came across the following antenna which covers the 80-10m bands with no traps and just one loading coil. As Figure 3 shows, this condition only exists for the center loading coil, but not for the mid-element coils. Here's the Variometer Coil at the 90 degree position. To me it seems that placing loading coils at the ends is the most efficient place, because more current flows at the at the feedpoint or base of an antenna. A loading coil is an induction device placed on a local loop longer than 18,000 feet that carries analog signals. Current baluns can also be used as isolators or unun's. {This assumes the coils are located The base model I ended up with (in 4nec2 . See more. Note the hole drilled in the coil shaft to allow the Variometer Coil connecting leads to exit the coil bucket through the tuning shaft at the left side. A loading coil is not a transformer as it does not provide coupling to another circuit. The vertical arm is constructed with 3 dipole arms, 1 red coil, and 1 standard whip. The configuration is easy enough to model in NEC with sensible results. Designing extremely short vertical dipole (1/7) > >> I got 4nec2 up and running again on my re-installed computer, and I've got a couple of questions on a short vertical dipole design I was playing with (mostly using information and sample antenna designs from N3OX posted here on eham). A New Antenna Model Think you know how an antenna radiates a signal? This article may give you some new insight. This simple fix can make a huge difference especially if you are having front end overload problems with signals that are too strong. I can use the optimization function to get values that are almost the same as the calculations above. 4. The Loading Coil . 4NEC2 – Free version of NEC 2. It’s a great HF antenna for the ham radio operator with a smaller backyard! The Loading definition, the act of a person or thing that loads. I have given much consideration to the coils used, and to their placement in the loaded antenna. These forms have a diameter of 1 1/2 inches and are 2 1/4 inches long. be sure to shield the RTL-SDR separately from these other components. This configuration was chosen because loading coils are always installed in pairs. 2 Loaded Q measurements of bare coils, via 3dB method . They were invented by Mihajlo Pupin, look him up in Wikipedia. 10/15/2017. Aug 15, 2010 distance or when using buried wires) were overcome with 4NEC2. e. • Loading changes antenna characteristics – Feed Impedance, Gain and Angle of Radiation – • No reduction in the requirements for – height above earth – ground/radial systems • With expedient application of the loading the efficiency of the system can be kept high – Apply ‘end’ loading first – Apply inductive loading in the The Variometer Coil set to the maximum inductance position. Department of Transportation defines steel coils several ways, including as metal rolls, coils, spools or coated electrical wire. exe - seems to be pretty close to reality. But for 40m, since 1/4WL is only 32' I'd usually strive to just make the vertical 32' tall and the heck with matching it. A dummy load can be purchased online or from your local electronics shop for a few dollars. It is best if you read about loading coils and loading in “Principles of Electricity”. . The text below refers to the left (inverted L-formed) version, though the electrical principals are mainly the same for both versions. In these cases, you can consider using a dedicated coil car that can be staged with a coil and always ready when the coil changeover occurs (see Figures 2 and 3). In some instances, one car may be able to service two adjacent press 3-element Coil-loaded Yagi for 40 Meters Loading coils must be high Q to keep loss low in a yagi, which means large, and large means increased wind and ice Indoor Counterpoise For Random Wire Antenna (too old to reply) tuner contains a loading coil to assist in tuning or the free 4NEC2, and proceed The federal government and many states have passed laws governing the hauling of steel coils by trucks and the various safety precautions that must be undertaken when transporting steel coils. Another way is to stack elements and feed them in phase so that their patterns reinforce. 40 M. , at the feedpoint) requires the smallest amount of inductance. 088 Henry. This loading inductor is near the bottom of a 43-foot tall vertical. 2 Analysis of Coil-Loaded Thin-Wire. quotes] coil [like a bug catcher or a screwdriver]. There was an exchange of arguments on the subject of current in the loading coils, with W8JI insisting on constant current across the coil. antenna in 4NEC2 program in terms of input impedance and gain? May 11, 2012 The design uses loading coils at the ends and large capacity hats (six . The reduced length is of course to support reduced space availability. Yes I know that efficiency will be lousy on 160 and 600m, but I am a big kid, I still get a kick of working a station even just a suburb away. Mar 19, 2018 The design has been modeled in 4NEC2. On the other hand, your info on the unexpected large amount of pruning likely to be needed on multi-element insulated wire antennas is a useful coil system easily installs between the antenna’s end cap and the current antenna wire system. velocity factor of 5 percent by the fact that this corresponds to a change in wire capacitance of 10 percent. 1:1 Balun RG316 Ferrite Core. 4Nec2 tells me that I need 4. by Arie Voors 4nec2 is a completely free Nec2, Nec4 and windows based tool for creating, viewing, optimizing and checking 2D and 3D style antenna geometry structures and generate, display and/or compare near/far-field radiation patterns for both the starting and experienced antenna modeler. While many amateurs are likely to have good practical knowledge of antennas, how to construct them, how to All information, images, and documents on this website are the sole property of MFJ Enterprises, Inc. Attempts  Sep 6, 2015 This is due to capacitive end loading ('End Effect') which makes an antenna Yesterday I made two additional CoCos from same coil of coax, one with . After many tests and research they came to the conclusion that the selfinduction is going through a maximum when the cross section has a rectangular form (Thickness is same as width) like in fig. I used the MFJ 259 b meter to check inductances and found a coil in my junk box that had 55 uH inductance (shown in later slides). 3, 11/18/2010. Loading definition, the act of a person or thing that loads. There may be a few parameters you have to set Settings->CharImp set to 25 ohms Because, when this antenna resonates is close to 25ohms, this implies that you have a 2:1 balun like the budipole TRSB and it is set to 2:1. Loading coils cause distortion at the higher frequencies used to carry digital information and so are not used on these local loops. coil. loading coils, traps, etc  Feb 4, 2019 4nec2 pretty much relies on whatever the underlying NEC can provide. And based on the tap point, the inductance required works out to be right around 10 uH! So all the modeling - both of the dipole using 4nec2, and of the coil using solnoid3. A silver wire winding on good isolation materal may produce a coil with Q ~= 250, an air based large diameter loading coil could have Q ~= 800. A loading coil may be used, on its own or in conjunction with a capacity hat, to tune the antenna to resonance at a lower frequency. Top Loading Guidelines • Make the vertical as tall as you can for best efficiency • Do what you can with left-over wire length at the top, either T or L • Add loading coil at base if needed to make it easier to tune • For an Inverted L, making the total wire length = λ/4 = 130 ft will get you close I've been playing with 4nec2 and it doesn't like placing loading coils at the ends of wires. 38 / DSP 1. nec format) is shown below in Table 1. Many factors affects a coil's Q. The purpose of this article is to provide a procedure for determining the number of degrees of antenna occupied by a loading coil. The advantage of the method I described is that one does not need to do a lot of iterative modeling to arrive at the two impedances needed to make the antenna dual band. High Q loading coil will reduce the power loss in the loading coil, but also All information, images, and documents on this website are the sole property of MFJ Enterprises, Inc. After reading Tony’s write-up on his portable linked inverted V dipole ( April 2017 Nerg News) I was motivated to see if I could do a workable model for the antenna in a general purpose antenna modelling package, for me the best choice for this is 4nec2, it is free, and has many features even the paid for packages don’t offer. In addition, a finite   After the 4nec2 program is started, by default, the last loaded Nec2/4 file input-file is the nec input-file (First FR card) is used to get to coil reactance. OFF Center Fed/Loaded HF Antennas VE3KL •Searching for the elusive 40,30,20 m Short Antenna •Small, no bulky traps, minimum of components •Leads to a general design approach for a broad class I was curious if there was a website out there maybe with a calculator that is a good resource for learning how to load an antenna? Ive built a a few for wifi and ADS-B but the coil dimensions are always given I cant seem to find out how to make one from scratch for a particular frequency, also would adding a ground plain to loaded antenna give better reception? 2008 Antenna Modeling for Radio Amateurs 2010 Facts About SWR, Reflected Power, and Power Transfer on Real Transmission Lines with Loss 2011 Conjugate Match Myths 2012 Transmission Line Filters Beyond Stubs and Traps 2013 Bode, Chu, Fano, Wheeler –Antenna Q and Match Bandwidth 2014 A Transmission Line Power Paradox and Its Resolution I played around with the taps on the loading coil until I could hear the signals/noise peak around 7 MHz. • Loading changes antenna characteristics – Feed Impedance, Gain and Angle of Radiation – • No reduction in the requirements for – height above earth – ground/radial systems • With expedient application of the loading the efficiency of the system can be kept high – Apply ‘end’ loading first – Apply inductive loading in the Loading Coils for 136 kHz. The antenna impedance loading technique, that offers a multiplicity of degrees of the circuit 'E' corresponds to a coil of 10 turns, of length 10 cm and diameter been borrowed, after some changes, from the 4NEC2 example catalog. It is called the EFHW-8010. If you increase the length beyond 5/8w though, high angle lobes begin to appear and the low angle lobes become less intense. How to use loading in a sentence. Here is a photograph of a loading coil: In this photograph there are actually two coils in one physical package. You have no items to compare. the output from MATLAB we turn to the simulation software of choice, 4Nec2. This page starts by showing how to make loading coils for LF, and goes on to describe two of the loading coil assemblies used to resonate the experimental vertical antenna used at GW4ALG. 3 Summary of . However with a bit more top loading the optimal place suddenly moved to the top. For 40/80m, a relay can switch in a coil for the lower band and short it out for the higher band. The coil was mounted on nylon screws and coils were made rigid with epoxy. DB are you telling me your model with a coil is using the load feature in 4Nec2, or that you physically added the coil to the model? We recently discussed adding a physical matcher to a antenna models. The resultant integral of the current and length [in degrees] [ampere*degrees] of the resulting antenna is higher with the short fat coil than with a long thin coil. Paul McMahon VK3DIP. com. (Insurance) an Coil Inductance. 8 and so on). In general, an HF loading coil can be treated somewhat like a transmission current "bulge" inside a loading coil that affects losses in the coil. Modeling My HF2V Butternut. tive reactance with loading coils some- where in the antenna structure. 2. Coil loading and unloading can be as difficult and unsafe as tool loading, then using our 20 years experience in quick die change , we have developed specific solutions to handle coils. This is a VERY brief summary of the common loading coil, 88 mH (milli-Henrys), which is 0. It is neither an amplifier nor a repeater. Build an effective dipole antenna that needs much less space by adding two loading coils. This online calculator tells you the amount of inductance your loading coil we need to   Purpose: To specify the impedance loading on one segment or a number of segments. EZNEC (or 4NEC2) lets you fool around with the placement of the coil, which is kind of slick. The loading coil has an rf resistance which varies according to the total inductance of the coil and the working frequency, but although it is possible to have the 4nec2 optimiser adjust the coil inductance for resonance, the It didn’t take too long to whip up the whole model and run it, optimizing the inductance of the loading coil for minimum SWR in the middle of the 20m band. This is a little more than 10 percent of the total resistance. We hope CARA members have found this article useful and will take advantage of the and often have lower loss. Detail Of. High Q: 20 m monoband antenna  The base model I ended up with (in 4nec2 . Series and parallel RLC circuits can be generated. [EDITORS Note – If you want to get a copy of this to load into 4nec2 please email me and I will send you a copy] NERG NEWS August 2017 Page 2 of 10 The Variometer Coil set to the maximum inductance position. 5. The wire was  EZNEC and 4nec2 are based upon the Numerical Electromagnetics Code, or NEC, which is a •Loading coils/tuned traps etc can also be added to any wire. At the right you see a smaller version, C- and L-values are adapted to a total antenna length of 2. 19 is the same, and when the average diameter is the same is 3x the thicknes of the winding. What others are saying _____ Durante l’estate, in seguito al recupero di una canna da pesca a cui si era rotta la sezione di maggior diametro, ho effettuato un montaggio semiprovvisorio sul tetto. Good news from Elecraft. edu is a platform for academics to share research papers. Oct 22, 2017 Going to run the 4NEC2 model on the Square Wave Beverage and see where that The Hi-Z verticals do not use any loading wires or coils. We also achieved some late afternoon 40m contacts with the coil out of circuit Once 80-10m are working, 160m will be tried with a top hat loading wire and a counterpoise radial. The device compensates for wire capacitance and boosts the frequencies carrying the voice information. You can shorten a vertical antenna by using a loading coil. because some antenna simulations using 4nec2 seemed to indicate  Oct 10, 2016 use the horizontal FD-4 with added coil and 30 feet of wire which is then also or balun losses I got the following load dissipation figures with 100W applied: . • Loading changes antenna characteristics – Feed Impedance, Gain and Angle of Radiation – • No reduction in the requirements for – height above earth – ground/radial systems • With expedient application of the loading the efficiency of the system can be kept high – Apply ‘end’ loading first – Apply inductive loading in the In general, an HF loading coil can be treated somewhat like a transmission line with a characteristic impedance and electrical length. The NEC2 Detail view of loading coil looking back to feed point. However, the antenna did act like a small loop antenna with coils rather . Many magnetic field coupling circuits, such as chokes and transformers, take advantage of a coil’s magnetic storage properties. This online calculator tells you how the amout of inductance your loading coil will need to have. This is my model (so far) for the shortened 20m vertical I’ve been designing, as visualized by 4Nec2. The Hi-Q website will reflect all of the changes after my return from vacation end Of September. a broad class of HF Antennas. 88. In this work, we have measured the radon gas concentration in the environmental ground water sample of some regions in Anbar governorate by nuclear track detector (CR-39). See loading coil. May 30, 1991 lines, perfect and imperfect conductors, lumped element loading, and behaves like one-turn coil, and the impedance becomes more  based on a new design with the help of 4NEC2 software and using Before the three elements wire beam, I used a 5/8λ top loaded vertical on 18m Design 2: the “coil one”, with coils and relays at the top of the parasitic elements to switch. The loading coil is a passive device and does not receive any external power. You have no items in your shopping cart. Introduction. The antenna is resonate on both bands and does not require an antenna tuner. Inductance is the ability to store energy in a magnetic field, and coils are a common way to create inductance. Mobile loading coils or loading coils for short antennas often have very high reactance. The coil wire itself was some 18 gauge hook up wire that turned out to be too large for my protoboard, so I am glad it found a good home in the matching coil. inductive. Using more than 1 dipole arm helps make the antenna longer and more effective. Required loading-coil inductance as function of coil placement. The reduced half sloper reduced half sloper adds a loading coil and shortens the wire accordingly. com Define loadings. 4nec2 [4] is a free NEC2-based modelling and analysis program which, via a  The computer simulation will be done using 4NEC2 [1], an electromagnetic modeling . ( Remember: In the load card “LD” in the true NEC file there was only one  Build an effective, shortened vertical antenna by adding a loading coil. Vertical. Hence, the calculations you make for mid-element loading coils will be slightly less precise relative to building the coil. One coil placed in the centre or at the base of a single-band vertical antenna is sufficient, but a single-band dipole will require two coils - one in each element of the dipole. The document has moved here. The loading coil represents 3 Ohms of the total radiation and loss resistance of 28 Ohms. you mentioned that you used 4nec2 for modeling the antenna. The. If you wish to perform loading coil in a vertical HF quarter wave antenna in order to be able to shorten the monopole to a manageable size. as 4nec2 (http://www. The top of the coil goes to the antenna. 2-uH loading coil in the middle, and a 2-ft-long capacity hat at the top. The loading coil's Q is defined by the reactance of the inductor divided by the resisteance. loadings synonyms, loadings pronunciation, loadings translation, English dictionary definition of loadings. A loading coil or load coil is an inductor that is inserted into an electronic circuit to increase its inductance. It's just a coil. They require a 5 pin coil socket. 647 MHz) renders the dipole resonant on the 80 (actually 75) meter band, while resistor R has as sole function bleeding off static charges, hence protecting capacitor C. Two wires are coiled into the shape of a flat doughnut, often referred to as a torrid form. A honeycomb coil is not more then a one layer cilinder coil. 3:1. normal mode has a “built in” loading coil, and thereby has a lower resonant . Academia. However I just simulated a 10m L antenna in MMANA and it gave me that the optimal place for the coil is close to the bottom. Fig a) above is an attempt to portray a colinear vertical over infinite ground with a source at "S". The U. 4NEC2 Antenna Modelr and Optimizer. S. passing through the helix, but rather as a top loaded monopole. I could be wrong, but I'm not too sure that adding a physical matching device to our models will produce good results. So why not always use center-loading? This is primarily driven by coil losses, hence, efficiency of the antenna. comportco. 5. 4NEC2. a loading coil to make it look like a 3/4 w antenna and it has a resonant low impedance again. Coils. This 40 and 80 meter inverted V antenna is made with loading coils. Loading it as A Half Wave on 80M Coil Coil 70 ft 72ΩTwinlead Choke ANT TUNER Building Wire Antennas • Use Insulated House Wire (THHN) – #10 or #12 for heavy loads, long spans – #14 for lighter antennas – #18 or even #22 for stealth! • Use thimbles where wire bends to minimize stresses – • – โปรแกรม 4nec2 ใช้พื้นฐานมาจาก nec-2 แบบเดียวกับ eznec น่าใช้งานมาก การแสดงผลดูดีกว่า สวยงามกว่า แต่วิธีการใช้งานยุ่งยากกว่าในหลายๆ This Tooling U-SME Metal Stamping Training covers how to handle and load coil onto uncoiler, thread the straightener and feed coil stock into the die area. Apr 21, 2016 Now for some question we might hope 4NEC2 can answer. Can somebody tell me how to build a tapped loading coil (yes I know it will be large) that I can switch in to cover those bands. This gives the crane or forklift operator a significant amount of time to retrieve and prepare a load-side coil. I used band switching in my amplifier because I only had two coil forms and I wanted to avoid having to switch coils so often. qsl. Design spreadsheet for a tapped LF antenna loading coil ©Jim Moritz, M0BMU 26/7/2006 The tapped loading coil of Figure 1 is physically the simplest way of matching an LF transmitter to a vertical antenna. This online calculator tells you how. 2 uH of inductance in the coil to reach a minimum SWR of about 1. This loading coil is a good example of why high-reactance loading inductors should be longer and narrower than inductors used in low-impedance systems. The loaded counterpoise is built with a single dipole arm, a black coil and a standard whip. Matching. 17 . They have increased the KX3 power output on 80-20. It is a full size antenna on 40 meters and a shortened 80 meter antenna. Second, us-ing the coil’s reactance is good only for a single frequency. loading, resistive losses, or traps. Many variations are made of this type of coil. 4Nec2 allows me to do a frequency sweep calculation so I can see the SWR across the I've been playing with 4nec2 and it doesn't like placing loading coils at the ends of wires. The loads can have a resistive as well as a re-. 80/40 M. This effect sees the largish 80M loading coil acting more like a choke at the  So I decided to model it using 4nec2 and re-design it optimised for portable use. The radiating element is 12 feet tall with a 4. The hamstick has a higher current taper than the screwdriver or bugcatcher. Loading Coil Powdered Iron. Lets run it. The common explanation for operation of a) is that the U shaped section is a quarter wave s/c stub, that it is responsible for delivering direct The left picture shows the multi-resonant HF mobile antenna that I developed for my VW T3 Syncro 16". 4nec2 loading coil

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