A collection of electronic circuits for the hobbyist or student, links to related sites, commercial kits and projects, newsgroups and educational areas. Connect to download. Get pdf. IEEE Std 1411993 Red Electric Power Distribution for Industrial Plants. Reactance Calculator Program' title='Reactance Calculator Program' />The 8. Meter Inverted Vee OriginalW8. WWV The 8. 0. Meter Inverted Vee OriginalGreg Ordy. This page was my first 8. September 2. 00. 2 before I added the remaining pages. Ive left it as a preface to. The 8. 0 meter inverted vee is a common and classic antenna. Like. all inverted vees, it requires a single center support, which is often times a. Yagi or quad for the upper bands. Until recently. my tower supported a pair of. Reactance calculator R L C inductance inductor capacitance capacitor frequencyr Eberhard Sengpiel sengpielaudio. With my 6 element. I decided to replace the. This new antenna would be a good antenna to. While there are antennas which are more complex than an inverted. This page describes my 8. On this page, I am only considering the half wavelength inverted. Conceptually, the inverted vee starts as a horizontal half wavelength. The dipole has a. While any angle other than 1. An often discussed range is 9. Why might the inverted vee be preferred to the dipole The first. The dipole will require at least two, and if the dipole and feed line. The single center mounting point of the inverted vee can. Since the two legs of the antenna. If the apex angle is 9. Since an. 8. 0 meter dipole is approximately 1. Another often cited reason is that the inverted vee makes a. Ohm feed line.   The resonant half. Ohms. I used the word. Ohms. The impedance. Reactance Calculator Program' title='Reactance Calculator Program' />Programs to design some of the most common types of antennas and a some experimental antenna designs. The Transistor Amplifier is available as a. New items are added on a daily basis as we get a lot of. In other words, the impedance of the resonant. Ohms. In order to have a. Ohms, the dipole cannot be too close to the ground. As the. dipole is brought closer to the ground, the impedance will drop. Even though this dipole is resonant, its SWR in a 5. Ohm system. is not 1. Its SWR is 7. 25. While this SWR usually implies a very. SWR limit. We may be limited by our. SWR less than some value. Lowering the minimum SWR of an antenna is often useful in order to. Of course another common solution is to add an. To create an inverted vee from a dipole, we simply have to lower. As you lower the ends, the feed point resistance. When we reach an angle of approximately 9. Ohms. This is now a perfect match to a 5. Ohm transmission line. The SWR at resonance is 1. Keygen Surfer 12 Software more. So, the typical vee is simpler to support, and provides a. Ohm transmission line. At the same time, the radiation pattern of the vee will no. I modeled both a dipole and. MHz using EZNEC. The antennas were 1. Each. center was 5. The dipole was uniformly 5. The ground model was real, with average quality. Here are some of the characteristics of the two antennas. Resonant Dipole. and Inverted Vee Comparison 3. MHz, 5. 0 ApexAntenna. Dipole. Inverted Vee 9. Maximum Gain. 6. 4. Bi. 3. 3. 5 d. Bi. Take Off Angle max. Feed Point Resistance. Ohms. 47. 3 Ohms. SWR Bandwidth 2 12. KHz 7. 5 Ohms1. KHz 5. OhmsThe inverted vee does give up 3 d. B at high take off angles. Other than the gain difference, at high angles, both antennas have basically. Due to the relatively low height above ground, both antennas. At lower take off angles, however, the inverted vee maintains a. The. next picture is a graphic overlay of the antenna patterns for the azimuth. The dipole response is in black, and the inverted vee is drawn. The inverted vee has the additional characteristic that it is. Giving up some gain with the vee is usually not much of a. NVIS near vertical incidence skywave local contacts. A bit. more bothersome is the fact that the vee has a smaller bandwidth for a. SWR. Here are the SWR graphs for the two modeled antennas. In order to achieve the largest possible bandwidth with the. Ohm transmission line. This is. because the dipole impedance at resonance is close to 7. Ohms, which is much. Ohms, as opposed to 5. Ohms. When the dipole is driven with a 5. SWR bandwidth is almost identical to the vee 1. KHz. Both. graphs are plotted relative to a 5. Ohm feed. So, the dipole offers more. Ohms as opposed. to 5. The ON4. UN book 3rd and 4th editions has a section on the. A number of parameters are considered. He also concludes that a. A 1. 20 degree vee has a wider. If you are looking for a general. Ohm transmission line, the inverted vee may be a good choice. There is no. magic to the antenna, and maximum gain will usually suffer a little compared to. Then again, the more rounded pattern will provide more uniform. In the infinite universe of numbers, a few are burned into the. The first is 4. 92. That is the number of feet in. MHz. This is a free space half wavelength, which. For frequencies other than 1. MHz, you need to divide 4. MHz. Our antennas are not. In the metal, the speed. The classic next number used is 4. A half wavelength. FMHz feet long. If the target frequency was 1. MHz, a. half wavelength dipole would be 4. The dipole. is fed at the center of that span. While the 4. 92 value is close to the truth its closer to. This is why we have to trim our. Another number often quoted is 1. Divide by the frequency in MHz to find the. Now if a half wavelength at 1 MHz is 4. Well, due. to properties of the loop, the approximation often given for the resonant length. Turns out that there is a different number often cited for. The length of a vee needed to resonate at a certain frequency is. One. constant used is 4. Some sources will suggest that the number is 3 to 5. Often. Quoted Antenna Constants. Constant. Description. Length, in feet, of a half. MHz. 46. 8Length, in feet, of a half. MHz. 45. 0Length, in feet, of a half. MHz. 12. 40. Length, in feet, of an. Zepp EDZ in typical wire at 1. MHz. 10. 05. Length, in feet, of a full. MHz but. its wrong2. Length, in feet, of a. MHz. 15. 4My weight class, in pounds. Any of the numbers that apply to real wire antennas are only. Many folks suggest that you should cut the actual wire a little. Verticals constructed of tubing or towers will deviate substantially. For a more. serious look at antenna constants and cutting formulas, see Blunting the Edge of Cutting. Formulas, by L. B. Cebik, W4. RNL. If you submit inverted vee to your favorite Internet. A number of them are calculator. Its a little interesting. Makes you wonder if there is a lot of. I digress. I wanted my inverted vee to be resonant at 3. MHz. This. frequency is right above the phone DX window, and also close to some common. I submitted 3. 8 MHz to a number of these calculators. I decided to. begin with 6. I constructed my vee out of 1. I happened to have several thousand feet of that. Actually, solid wire of. Another popular wire due to its strong steel core and highly conductive. Copperweldtm. I have used this from time. Still, it is very good for a long term. Copperweld is carried by most. One feature which should not be overlooked is the use of a. RF choke at the feed point. This device encourages. RF current to stay off of the outside of the transmission line. This unbalanced. current causes the feed line to radiate, in addition to the antenna. This can. create all sorts of problems. First, your antenna is now a combination of an. Since the. transmission line is now part of the antenna, changes to its length will change. SWR on the feed line. Ideally, the SWR on a transmission line will be. The SWR should stay constant for different length transmisson lines. Actually, real transmission lines, due to loss, will lower the SWR towards 1. If you have an antenna where changing the transmission. SWR, odds are that the feed. Finally, the RF current. Several amateurs have made significant contributions in the area. Two that spring to mind are Walter. Maxwell, W2. DU, and Roy Lewallen, W7. EL. Both amateurs have written extensively on. Internet as well as from sources. ARRL. The W2. DU style balun consists of a number of ferrite beads or.