It allows you to test the resonant frequency of the antenna for lowest SWR and zero reactance, and adjust the length to the exact Mar 8, 2024 · What can this calculator be used for? helical antenna The calculator returns values for the axial propagation factor β and characteristic impedance Z c of the n = 0 (T 0) sheath helix waveguide mode for any helix dimensions at any frequency. Input both parameters in the resonant frequency formula: f = 1 / (2π × √(L × C)). RG-58 TRAP, 75 ohm VSWR, 40 METERS. Notify me when this item is in stock. Start by entering the Center Frequency and the Reduction Percentage in the area provided on the left. Use 4% for 37 degrees. 5 m between balun and 20m trap, 5. It is certainly convenient to put up. 5% 5. e. For a frequency of 14 MHz: Jan 11, 2021 · Here we will use the current sheet model for inductance and Knight’s expression for capacitance to come up with a spread sheet “calculator” that can be used to design coils for a particular self-resonant frequency. Diameter of the conductor in inches Antenna Trap Calculator. By providing insights into the necessary trap parameters, it enables the creation of efficient multiband antennas suitable for a wide range of applications, including amateur radio, shortwave communications, and more. A trap consists of an inductance and a capacitance, normally resonated just at or below the lowest frequency of the higher antenna frequency range. Conversely, the 14 MHZ signal perceives the 21 and 28 MHZ traps as a closed switches at 14 MHZ. | Quarter-wave Vertical | Height = feet. With this, three combinations can be made on the antenna trap circuit board. The resource is currently on dxzone. Article published on QST, author andRead More Once you are happy that your trap is tuned up properly; tighten the nut to hold the turns firmly. Write down the inductance L in henries. A half wave is, well, a halfwave, for a given band. 1,2,3 As shown in Fig 2, the in-ner conductor of the coil end is con-nected to the outer conductor at the beginning. ω ω L = . Learn more about dipole antennas and other RF topics at everything RF. The radiating element is a quarter wave (λ/4) and the radials are 12% longer. Specifically, it measures the number of signal units per second that are transmitted, with each unit capable of carrying multiple bits of information. If the ratio (L/W) is close to unity, the radiation pattern will This calculator can be used to design a Slim Jim or a J Pole antenna. 8-MHz traps. Frequency can be entered to find the Q of the inductor at a On-line antenna designer. htm This is the one you've been waiting for - the traps to go with the micro End Fed Halfwave (EFHW) antenna build. The trap can consist of a coil and a separate HV-capacitor. Part Number: SBM-HFAT-101. So far it received 231 votes for a total score of 5. Coax losses Calculator and Charts. Log ( ('amount of elements' - 1) * 0. This link has been on our site since Sunday Oct 28 2007, and it has been clicked on 46487 times. Fig. 8-MHz traps are 1. The resistance should be less than 0. Use 3% for 30 degrees. SOTAbeams HF Antenna Trap Kits. This calculator gives the lengths of the radiating element of a quarter wave (λ/4) ground plane monopole and the radials. Formula The total length (L) of the dipole antenna is calculated as: L = 468 / f where f is the frequency in MHz. values needed for placing the trap at any location along the antenna arms subject to Jun 23, 2020 · This electrically shortens the antenna and may provide sufficient effective shortening to provide a low SWR without any trimming. Subscribe. 45 feet for the 3. The scale is 1 - 10, with 1 being poor and 10 Calculating the inductance of an antenna trap is crucial for tuning your antenna to a specific frequency. The following program will calculate the lengths needed to construct several popular wire antennas. 66 inches apart. EZNEC #12AWG dipole. 99. Phone. Enter the desired frequency and select the wavelength. (David VK3AUU) 3. 141592653589. Oct 31, 2016 · The total length of this dipole antenna, including the two traps, is only 43. Note the left figure for the discrepancy between calculator vs HFSS. This type of antenna is a popular antenna design as the performance is very good across the HF bands and requires little or no tuning. Both metric and English units of measurement are supported. For example a 2-band-dipole needs one trap in each half of the antenna. Design an End-Fed Half-Wave (EFHW) antenna, in either an inverted-L or inverted-Vee form, using a single main support. 8} {f} \] where: \ (L\) is the inductance in microhenries (µH), \ (f\) is the frequency in megahertz (MHz). I’ve tried endfed halfwaves, random wires and fan dipoles and for various reasons, none of these antennas will work for my operating situation. Its fairly easy to use an ATU on an end fed antenna to get other bands May 22, 2024 · Powered by @Calculator Ultra The baud rate is a crucial metric in telecommunications and electronics that indicates the speed at which data is transmitted over a channel. I fund that most of web calculator for traps calculate XL in ~200ohms, but I want to understand why, and how to make good trap for e. 12 feet. Antenna Type: ¼ wave (vertical) ½ wave (dipole) ½ wave (inverted "V")* ⅝ wave Full wave (loop) Type of wire: Bare Insulated. HOW THE TRAP ANTENNA WORKS The multi-band trap antenna is not a new concept. September 2014. Use our simple calculator to determine approximate dimensions of materials needed to build a vertical antenna. λ = λ/2 = λ/4 = feet. This is a true unbalanced antenna, with a feed impedance of around 50Ω and therefore a great The trap is situated 1/4 wave length from the boom of a yagi and is similar to that of an open switch. g. The correct lengths for the various models will be displayed in the chart. COAX PHASING calculator. 5 m between 20 m trap and 40 m trap and 11 m between the 40 m trap and the end of the antenna. Article in Dutch with some interesting pictures. This information is useful for designing: HF Antenna Calculator Set Freq = MHz. m. They feature special traps made with of PTFE (Teflon®) insulated coax for high Q and low losses, offer high performance multi-band operations—and are excellent shortened The calculator above is accurate for sufficiently large horns. With the SARK-110 Antenna Analyser is very easy measuring the resonance frequency and the impedance characteristics of traps. net Abstract A coaxial-cable trap dipole antenna installed in the attic provides a surprisingly effective solution to HF operation on the 10, 15, 20, 30, 40, and 80 meter amateur bands at a QTH with restrictive covenants that prohibit outside antennas. I'm looking for some good article about trap designing. A trap effectively consists of a series combination of resistance and inductive reactance in parallel with capacitive reactance Homebew Coax Traps. Two 20 m traps can be added to include a third band if desired. Long / Random / End-fed Antennas. Inner Frequency in MHz (trapped, higher frequency) Outer Frequency in MHz (untrapped, lower frequency) Normal dipole length in meters (determined by outer frequency): This video is about the stuff that goes into the successful design of a trapped antenna. Long yagis are commonly used from the 144MHz amateur band to the 2. We know that many antennas can effectively resonate and work in more than one band, one of which is called a Trap antenna. Enter your location and the broadcast towers in your area for a comprehensive overview of your antenna's potential range. The report May 13, 2020 · Here's a picture of the model: This produces a 50- Ω Ω SWR curve that should be a reasonable starting point for further optimization: The resonant frequencies are: 7. Jun 9, 2021 · Calculator tool; Trap construction; Assembly and tuning; I have 50 feet of room for an antenna at my QTH. Note: Configuration and height above ground will affect the match, especially on 40M. 9. Enter desired frequency MHz. See More Specifications. L = 468 / f L = 468/f. An antenna analyzer makes tuning the antenna easier but it can also be adjusted by checking the SWR at the lower and Mar 7, 2019 · A plain half-wave dipole made of thin wire should have a 2:1 SWR fractional bandwidth in the neighborhood of 6% if losses are low. the 7 MHz or 40 meter (USA) band. 15 MHz)= 1. These lengths include the trap pigtails and a few This calculator was created for use with the short whip antenna calculator to obtain a resonant antenna matching circuit for the RF transmitter PA section, but can also be used to make antenna traps, resonant circuits, low pass filters, etc. Calculator 1: This calculates the Resonant Frequency of the LC tank circuit by entering the inductance and capacitance values. Related Calculators. Three-band Linear Trap Dipole designed by G3TKN. Enter your desired frequency (MHz) of operation (i. Traps can be one way round multiband coverage without the need of an atu. Enter the desired operating frequency in megahertz to get a good starting length for a dipole in both feet and meters. Oct 25, 2023 · The Antenna Trap Calculator plays a pivotal role in designing and fine-tuning antennas equipped with traps. Click on Calculate and the optimum length 1 day ago · To calculate the resonant frequency of a circuit composed of an inductor and a capacitor, follow these steps: Write down the capacitance C in farads. In this guide, we will explore how to use a simple formula to calculate antenna trap inductance. Dipole Antenna Calculator. The Wire Size can range from 16 AWG to 12 AWG. Feb 23, 2023 · W1YW Ham Member QRZ Page. My bands of interest are 40/30/20 and 17m. 1. Input Impedance (Edge): Ohm. Antenna Trap Calculator - Design your own antenna trap online 7 Mhz traps for W3DZZ - Homebrewing traps for the W3DZZ wire dipole Antennas. Toggle navigation. f f — The resonant frequency; A. 55). 4GHz band. This tool calculates the physical dimensions of a 2 meter dipole antenna. Adding a broadband transformer to match 35- Ω Ω improves the SWR: Dec 12, 2021 · Enter the frequency in MHZ --> http://vwlowen. Optimum Gain Concial Horn (max gain for a given aperture size) (Reference: King's optimum conical horn) Freq (GHz) A (inch) D (inch) H (inch) Gain (dB) Wavelength to Frequency. Share. 1 and. The Trap in the figure is a 1/4 λ transmission line (50Ω coaxial cable, such as RG-58/U) with a short circuit at one end and a resonant frequency of 14MHz. 3 diagrams the circuitry of a 3-band Homebew Coax Traps. The K5HH Antenna Calculators are for demonstration purposes only and may not reflect actual numbers for your equipment. For n working frequencies of an antenna, you need n-1 traps in each part of the antenna. Antenna traps are used in multi-band antennas to isolate certain frequency bands, and understanding their inductance is essential. It sounds complicated but it really couldn’t be simpler to build, erect and use. 39 * Math. The measurements below are for building a simple Dipole Antenna. I show what kind of effects the Resonant Frequency, Q and Capacitan Parallel-resonant circuits (called traps) are widely used to isolate parts of multiband antennas to make the antenna resonant on different fre-quencies (see Fig 1). This article provides a step-by-step guide, formula, example solve, and FAQs to help you optimize your antenna for better performance. Choose from quarter-wave, half-wave, the powerful 5/8-wave, 3/4-wave, or full-wave, and calculate minimum lengths of required radials, and then shop for your needs on our other pages and select from our inventory of aluminum, fiberglass, wire, coax, connectors, and other parts and Gain calculation and why approximate. HF Antenna Trap Kit, Pair, 100W, Choose 7-25 MHz by Construction, Pack of Parts to Build 2 Traps, Online Instructions, Kit. 0% 3. Traps simply act like a switch electrically cutting off the rest of the antenna at its design frequency, and that comprise the trap, 2 00 0 0. Center Frequency: Reduction Percentage: 3. However, ultimate responsibility for the proper use of your equipment lies with you. 160-10m, 80-10m We would like to show you a description here but the site won’t allow us. Delta Loop Antennas (11) Double Bazooka (10) Half Wave End Fed Antenna (27) HF G5RV Antenna (2) Coax losses Calculator and Charts. 10 under Wine, to produce dimensions for a DL6WU style long Yagi antenna. At 2 meters, the dipole length (L) is 3. 138 and 0. +44 (0) 7753225261. The calculation refers to either a loaded 1/4 wave or a loaded dipole, Loop antenna resonant frequency calculator. 15 =. Trap Antenna Design Calculator. 158 inches thick (3. Cookie Policy. 26 meters--small enough to fit in many urban backyards. Bootstrap coax traps for antennas. We also used the simple wavelength formula: Wavelength = c / f. Coaxial Traps for multiband antennas. Enter a length between 1 and 500 feet. Enter the required frequency in MHz, the velocity factor of the coax Just enter your specific requirements in the area provided. (requires Excel via Microsoft Office). Distance from center of antenna to the center of the coil in feet (Must be less than half the total antenna length given above) Enter a distance between 0 and 250 feet that is less than half the total antenna length. This has not been tested on VHF (50MHz and above) banana-antenna-calculator No macros are embedded with this file. Calculator Enter Frequency or wavelength of operation, Velocity factor % increase of radial length over the main vertical radiating element (0% means the radial length is the same as the monopole) The resonant frequency of an LC Circuit is the frequency at which the inductive reactance and capacitive reactance of the LC circuit are equal. A new perspective on the analysis and design of this popular antenna element. So if your trap dipole has a bandwidth wider than that, it's a fair inference that antenna efficiency isn't great. The antenna shown covers 80, 40, 20 and 10 meters. The antenna wire lengths before trimming are 5. You need this—traps with lower loss, higher Q, increased power-handling capability and four-band coverage! This improved multiband trap dipole introduces a new trap design and a change in trap location. (Image source: PulseLarsen Antennas) The KGI825 can handle up to 60 watts of transmit power and offers convenient magnetic mounting inside a window between 0. Use our TV antenna range calculator to determine the optimal placement of your antenna and find the best TV antenna for your needs. The gain calculation is based on four formulas to calculate the gain for directional yagi type antennas. This article explores a theoretical model for the losses of an 80m / 40m trapped inverted V dipole antenna system using a bootstrap coax trap. This antenna calculator uses all four and then divides the results by four giving the average. Even though most reports suggest it should be used as a vertical antenna it requires no radials or counterpoise wires. Open the dipole length calculator in a separate page. The performance of any antenna depends upon many factors, not the least of which is its design. The only remaining design parameter is where along the dipole arms to insert the trap. Use 5% for 45 degrees (The calculator should already be set for 5, if not change it to your desired angle using ONLY the percentages below. TRAP is like an electronic switch. Trap is a combination of an inductor and a capacitor, usually connected in parallel by an inductor and a capacitor. The three larger holes can be used to thread your An Attic Coaxial-Cable Trap Dipole for 10, 15, 20, 30, 40, and 80 Meters John DeGood, NU3E nu3e@arrl. The Banana Antenna Calculator allows you to input any frequency and achieve accurate measurements to achieve a precise build for all Amateur Radio HF Bands. 56 feet. It’s a dipole fed off center with a 4:1 balun at the offset feed point. multiband EFHW antenna. Test your trap by connecting an Ohm meter between the antenna pads - marked “Ant”. Reference to such a design can be found in a 1940 issue of Electronics. The primary issues are: The impedance varies over a very wide range, depending on the length in wavelengths. TYPICAL TRAP FOR 20–15–10 This calculator is designed to give the vertical length (height) of a particular antenna, for the frequency and wavelength chosen. EFHW antenna designer. Wire Antenna Calculator. 0%. Calculate the required dimensions for a coaxial collinear antenna construction for any given frequency. This article provides a step-by-step guide, the relevant formula (L=468/f), and practical examples. Calculations are based using PI (π) = 3. | Half-wave Dipole + Inverted-V Resonant on odd harmonics. zip & read the HELP ! My technique is to use my Marconi RF signal generator at +10dBm output into the coaxial trap (wired in series) and thence into a RF probe and then into a DMM You need this—traps with lower loss, higher Q, increased power-handling capability and four-band coverage! This improved multiband trap dipole introduces a new trap design and a change in trap location. The unspliced lengths are 17. These lengths include the trap pigtails and a few A trap dipole, in it's simplest form, might be a two band antenna for say, 80/40 Meters, as in Fig. This online resonant frequency calculator is divided in to three calculators. The Lopes design process gives the equations that calculate the . Delta Loop Antennas (11) Double Bazooka (10) Half Wave End Fed Antenna (27) HF G5RV Antenna (2) 3 days ago · Calculation Formula. 7 Mhz traps for W3DZZ. The coax trap will also shorten the length of the wire antenna, making it perfect for the Details. Sep 5, 2023 · Efhw Antenna Formula. 6 dB. The holes in the 3. Use 2% for 22 degrees. v1. 06 dB Jun 16, 2021 · This is a calculator to assist with designing a two band shortened trap dipole. NOTE: This is not an antenna for the beginner antenna builder! If you fall into this category, please read the notes at the end of this article. The antenna is designed to be fed with 50 or 75 Ohm Coax Cable of most any length with a Balun. . 375-MHz with 300-kHz of 2:1 SWR bandwidth. Antenna Trap Design. Place a 1:1 Balun on the Antenna end of the Feedline. This calculator is also simple enough. The article is an analysis of an antenna trap where a coil is formed of a length of coax cable, the outer conductor of one coax end is tied to the inner conductor of the other coax end, and the remaining connections (outer at one end and inner at the other) form the terminals A trap is a parallel circuit of L and C on the frequency you want to close an antenna segment. The result will be the length of the antenna in feet. HF Kits supplies two high voltage capacitors of 100 pF in the kit. In the parallel design, several dipoles are joined together in the center and fed with the same cable. uk/java/trap. Tuesday May 2024. Emphasis will be for short coils where the lumped circuit approximations fare best. Traps are tuned circuits that act somewhat like automatically switched inductors or capacitors, adding or subtracting from the length of the antenna according to the frequency of your signal. An end-fed wire often seems like the simplest type of antenna, but getting it to work well is actually rather complex. 55 feet for the 7-MHz traps and 28. Therefore the Use this online calculator to determine the length of a quarter-wave antenna from the frequency. It requires some sort of ground connection to work. For more than 20 years these circuits have been imple-mented as coils wound from coaxial cables. Feeding it at the end is a high voltage point, which requires a matching unit--usually a toroidal /ferrite system nowadays at the end-feed--and incurs losses. The Slim Jim, designed by the late Fred Judd, G2BCX, can be a great portable 'roll up' antenna, if made out of 300Ω or 450Ω ladder line / twin feeder. It is used to make up a dual-band 80m/40m dipole where previously only a 40m dipole May 26, 2022 · Figure 8: The KGI825 is a quarter-wavelength dipole antenna with 2 dB gain and a center frequency of 851 MHz. 5% 4. When the frequency of the electric wave Jun 5, 2021 · The Antenna CalculatorforHalf-Wave Dipoles. Find answers to frequently asked questions and conclude with a full HTML code for your convenience. Enter The Frequency For The Dipole/Vee Antenna Calculation. 3. The length of each element of the dipole (l) is half of that at 1. 5 to 4 millimeters). Information. Article in Dutch Coaxial Traps for multiband antennas - A new perspective on the analysis and design of this popular antenna MHz. 80 m 75 ohm VSWR. This article is a well-organized tutorial that explains the theory, design, and construction of a 20/40 meter trap dipole antenna, including a list of materials and how to build the traps. Here's how to make them. 75-MHz with 250-kHz of 2:1 SWR bandwidth. Main category is Antenna Calculators that is about Antenna design calculators. All you need to do is enter the desired resonant (center) frequency in the form below, then click "Calculate". The results will still be "in the ball park". So between the two Traps, the Dipole works at 14MHz; but for 7MHz, the Trap is inductive. 44 inches center to center, measured parallel to the trap center line. To fully understand the results obtained by this calculator, please take a few minutes to read the Simple and practical three-band TRAP DIPOLE. co. Width (W): mm mil. Inductance L (µH) 7 MHz RG-58 TRAP . 0% 4. The antenna connections are marked on the trap. HF. 06 dB 7 MHz RG-58 TRAP . HF Trap Calculator. Description. VSWR BW Coax trap 40 meter 2:1 VSWR ~ 80 kHz. where: L — the length of the total dipole antenna in feet (ft); l — the length of the arm of the dipole antenna in feet (ft); and. where: f. 11. Loading coils should reduce that bandwidth. In the program, choose: Tools –> Resonant Circuit. The 20 meter signal and uses the whole length of the element. f — the desired frequency. X LC. Kevlar. Inverted-V Antenna Calculator. Antenna Loading Coil Calculation. It can be compared to a regular dipole in that it is one half wavelength long. This article does not examine the pattern of the antenna, essentially as it is a low Inverted V dipole, it will have a nearly omni-directional pattern and with a relatively high main lobe. Mouse-over any image to see it larger! Let’s work through the design of a simple-to-construct low-cost antenna ‘trap’ - like the one pictured above - for the 40 metre band, i. Namely 50 pF, 100 pF and 200 pF. This type of antenna is designed for one principal amateur HF band, usually 80 meters or 40 meters, but typically displays VSWR minima on several higher bands, and can therefore be a good multi-band Inductive loading will electrically lengthen the antenna, and capacitive loading will electrically shorten the antenna. I have, in good faith, given my best efforts to provide a calculator that will save ham operators time in setting up their antennas. Example Calculation. The formula for calculating the approximate length of a dipole is: Dipole length in feet: 468 / frequency in MHz. There are usually four radials, three being a minimum, but you could use up to six. By the way, a good starting-point calculator for coax traps for multiband wire antennas is the Coaxial Trap Design software by Tony Field VE6YP - { download: coaxtrap. Item is on Order. The following formula is used to calculate the length of an End-Fed Half-Wave (EFHW) antenna. 1. 0 Dec 17, 2021 · T2LT or TTLT is an abbreviation of Tuned Transmission Line Trap. The parallel dipole uses a different approach. The larger the wire, the wider the bandwidth. X. com in 2 categories. The substrate parameters (ε r and h) are required. $23. Traps simply act like a switch electrically cutting off the rest of the antenna at its design frequency, and Use this online calculator to find the optimal length of a dipole antenna for any frequency. 05 dB . The formula for calculating an antenna trap in terms of its inductance (\ (L\)) for a given frequency (\ (f\)) in MHz is: \ [ L = \frac {31. 5 feet/13. This will then be used as a base for the other calculations. Learn how to use an Antenna Trap Calculator to determine the inductance of your antenna trap in just a few easy steps. Total trap loss = 0. ωω ω = == Finally, 0 2 00. Total coaxial trap loss at resonance on 40m= 1. 7-MHz traps are spaced I . XL and C LC. The total length of the 40 Meter section of the antenna is calculated by the usual formula, listed on the left and right. Learn how to use the EFHW Antenna Calculator to determine the ideal length for your antenna based on the desired frequency. Add a loop of string to the top, and hang it on a tree branch, use it with your handheld transceiver, then roll it up and May 21, 2021 · The Coaxial Trap, great for more than one band on a single antenna. (To better understand the variables This calculator can be used to design a Quarter Wave Ground Plane antenna, with radials. The limiting factor in a trap is the resistive loss of the coil, since the losses in capacitors at HF are very small. Find Kelemen Trap Dipole Antennas and get Free Shipping on Most Orders Over $99 at DX Engineering! Kelemen Trap Dipole Antennas are high-quality, heavy-duty pre-assembled wire antennas intended for permanent installations. l = L / 2. 5 Ohms. 3 days ago · The antenna length formulas used in our dipole length calculator are as follows: L = 468 / f. Each one gives its own results. 15 for the 40 meter band). 7. The microstrip patch antenna calculator determines the length (L) and width (W) of a rectangular microstrip patch antenna for a given resonant frequency or vice versa. First we will determine the value of the coil and capacitor. This electrically shortened dipole is similar in appearance to a trap dipole except the "traps" consist of coils only, causing the antenna to operate not unlike two mobile inductively loaded whips, mounted horizontally base-to-base. This application note describes basic measurement procedures using as example a homebrew coaxial This calculator is useful when making antenna matching units, low pass filters, crystal sets, antenna traps, resonant circuits or anywhere where an air cored single layer inductor is required. Dipoles antennas are easy to build and can be very effective when placed half a wavelenth or more above ground. The formula can also be used to adjust the overall length to cover more or fewer bands and the resulting overall length. Design your own antenna trap online. These traps will wor Low Cost Antenna Traps. However, many Hams are not completely familiar with the design principle of such antennas and so a brief description of this principle may be of interest. It also has the added advantage of shortening the overall length of an antenna significantly ,especially if more than one set of traps is used. Variables: L is the length of the antenna (feet) f is the frequency (MHz) To calculate the length of an EFHW antenna, divide 468 by the frequency in MHz. This does NOT take into consideration the type or size of horizontal reflectors, of even if there is a need for them. Estimated Antenna Length: Calculate. 49/10. Total coaxial trap loss 100kHz off-resonance (at 7. Wind the traps with a single length of coax core. The DL6WU yagi is highly regarded as being easy to build with repeatable results, broad bandwidth and a useful pattern. Diameter and length of inductor are entered in millimetres along with the number of turns. The antenna features double-coaxial-cable-wound traps having lower reactance and a higher quality factor (Q) than earlier coax-cable traps. If you have no particular preference within a given ham radio band, then simply enter its center frequency (i. Yagi Calculator is a Windows program that also runs well on Linux, Ubuntu 8. Prefilled values are for a 10/20m trapped dipole, with loading removing 20% of antenna length. The same electric circuit is present on 10 meters. Coax trap 80m 2:1 VSWR ~210 kHz. Homebrewing traps for the W3DZZ wire dipole Antennas. For 20 m traps use 9 turns of wire on a 42 mm PVC pipe and 500 mm of RG58 coax to begin with. Introduction. 2) + 9. The easy calculator yields a reasonable approximation of dimensions, to within 5% over the amateur bands, using typical wire gauges ranging from 12-18 AWG. mx bf xb dp km by ub vk ca fz