Depending on the antenna wire radius this turns out to be about 5dBi at ~12MHz with a 50mm wire [more like pipe] radius. Intensive 4th grade math to the rescue! 13. But, over the past few years the only antenna I had was the vertical. Product description. Has a length of 34 feet (10. That's not bad for a 1/10 wavelength antenna. The Matching Section is 450 Ohm Open Wire Feedline and is a compromise impedance between the 5/8 Wave antenna elements and the feed point, A 4:1 Current Balun. Features of the K0WA 40 meter verticle. Before going into the design of an antenna we must know about the performance parameters or characteristics of antenna for communication applications. It shall be easy to adjust (i. After looking at articles in the ARRL Antenna Book and on L. In the video I start with a length of 35' (10. This antenna was invented in the early 20 th century by two Japanese engineers named Uda and Yagi. Handles power up to 100W of RF. V/m = Volts per meter. G5RV Antenna 15 22. MonoBeam Yagi MB7 The MB7 10-15-20-40 is a quad band antenna for 7 MHz, 14 MHz, 21 MHz and 28 MHz with loading coil and capacitive hat for 40m only. 84 feet total length. Shortened 40 meter dipole shown with OPTIONAL "BL 10-160-5KW" Balun. The Buddipole™ - HF portable dipole antenna system. After attempting many antenna designs to overcome the physical constraints of my back garden, it was time to try a trapped dipole. 4 GHz 2 dBi Wi-Fi rubber ducky antenna design; left — the assembled antenna, middle and right — the disassembled antenna. A Simple Broad-Banded Folded Dipole. The measurements below are for building a simple Dipole Antenna. Buy Radiowavz Radiowavz Dx40 Off Center Fed (Ocf) Dipole Antenna - 40, 20, 10, And 6 Meters Antenna at Walmart. 95 * 1/4- wavelength from "center") and. The element can. http://astore. I have a 40 meter dipole which I used to compare reception. DXBeam DXD4030 1 Product Reviews EHam Net. The tower on the right in the picture supports the antenna as described above. End insulator to Loading coil 5 feet, 4 inches. The better your antenna, the more success you will have making contacts. The 20 meter dipole was a breeze compared to the 40. My first contact to Australia was on my 20 meter loop, so it has to be working great. Twenty meter screw-up! And the worst of it is: the whole antenna is based sequentially on each segment. $20 (Roseville macomb county ) pic hide this posting restore restore this posting. 12 dbi 433Mhz Antenna half-wave Dipole antenna SMA Male with Magnetic bTPO T ht; unopened, 12 dbi 433Mhz Antenna half-wave Dipole antenna SMA Male with Magnetic bTPO T ht. This dipole antenna consists of a matching balun, two telescoping elements, balun clamp for mounting, and a tape measure to adjust the element lengths. Ifan antenna has a gain ofO dBd, Dip. 5, 4, 6, and 10 meters (8, 13, 20, and 33 ft). For example, amossector = sectorInvertedAmos ('ArmWidth',0. Reisenauer, Jr. Trap dipole antenna for 20 / 40 meters The final antenna ended up being about 53 feet long, which is perfect for a portable, dual-band dipole, and good for some attics. 6 MHz and you arrive at an overall length of 130′. MFJ-2104$ 269. It covers the entire 40 meter band with a SWR of less than 1. With a 1064m2 (1/4 acre) town block with a depth of 60mtr (200') I intended to improve on my previous All Band HF Doublet with an antenna. This means that a a 20 metre antenna will give coverage between 5 and 25 MHz. Or outside on the roof, or between 2 trees or the side of a wall, or whatever you can imagine. There is some cancellation of energy on a line through the `gap' opposite the feedpoint, but it is minor in the `real' world performance. Itaughlorquena. 20-Meter “J” Pole Vertical. -wave antenna. Hence, the half-wavelength dipole antenna's length is 0. A couple of years ago I designed this antenna which had the good property of substantial low elevation gain and the model generated consistent and predictable 4NEC2 results. 2 MHz 2:9 14. The antenna has been tested to withstand. The 20 meter dipole was a breeze compared to the 40. The better your antenna, the more success you will have making contacts. The original sleeved dipole project idea is from Harold Melton KV5R. Flex-Seal, as seen on TV!. Rick, W3LQ. After attempting many antenna designs to overcome the physical constraints of my back garden, it was time to try a trapped dipole. MFJ-2104$ 269. I came up with an antenna that extended only 1. The 7 band OCF Dipole antenna was erected at 25 to 30 feet, on a hill side, using a military style push up mast, with a few customization on it. Did some slight adjustments to the length and we’re now all set to compare the vertical dipole I’m currently using and the horizontal dipole in the attic. 15 dBi10 Actual Antenna Lengths A dipole resonates best when it is approx. What intrigued me is that for NVIS work both he and the military found that inverted vee's with a center height of about fifteen feet and end heights of about 2. 0- mm ( (24- 12 AWG). The antenna’s low cost is made possible by modifying a RadioShack FM broadcast receiving antenna (RS 15-2163). each so you can trim the legs and get your best impedance match. There-fore, I decided to design a shortened loaded vertical dipole by making the bottom section an almost. Rotharachbanis. 80/40 Meter Attic Antena I live in a tightly packed urban neighborhood without much room for antennas. I decided to install an 40 meter dipole in my attic space which is about 25 by 45 feet, and about 25 feet up from the ground. Performance of a 20 Meter Vertical Collinear Antenna. Here are some typical OCF dipoles that are successful designs 160-6 meter Double Off Center Fed antenna layout (using a double tuned stub for better 20/40 meter performance) Here is the 160-6 meter SWR graph using 200 feet of RG213 feed line and an average height above ground of 35 feet: 80-10 meter OCF […]. A standard center fed dipole dipole for 40 Meters needs around 67 Feet of space. (See individual SWR plots, attachment 2 of 9). 5 on all the bands. The original antenna was designed as a moderately short antenna for the 10 meter band. That said, you will need two 10' sections on 10 meters, two 13' sections on 15 meters, two 18' sections on 20 meters, two 35' sections on 40 meters or two 70' sections on 80 meters to build a half wave dipole antenna for your band or bands of choice. 25, rising gradually to 2. It works and it works quite well. has it's greatest gain as a full size Extetended Double Zepp antenna. 20-Meter Vertical dipole antenna. Top wire for lowest band frequency (80 meters), determines overall antenna length. (Gain relative to a dipole is abbreviated as dBd. This is a low cost high-power circular dipole antenna with Type N RF connector. 5:1 for the 40-meter and 20-meter elements. We all know the horizontal dipole is one of the easiest antennas to build and is very common with new and old hams alike. 20 Meter Dipole at 20 feet. The only Mod I made to it other than personal choices of similar. Taoglas - Taoglas Introduces Flexible PCB Antenna for IoT/GNSS/Cellular Applications from 600 to 6000 MHz - Sep 09, 2021 Analog Devices - Analog Devices Introduces USB Powered 2. A 50 Ω coax connects directly to the coils. Drill the bracket. VK5AH -HF 4 Bander dipole. amossector = sectorInvertedAmos creates an inverted Amos sector antenna with four dipole-like arms. This is the length of a standard dipole but instead of dividing the result in half, use a 36/64% offset to determine the feedpoint. In 2011 I purchased a Cushcraft MA6V vertical that covers 20 to 6 meters. 10 Through 20 Meter Vertical Dipole (With a novel matching method) By KL7JR John F. Design Goals and Objective: Construct a compact, 20 meter rotatable dipole antenna of durable weather worthy components supported at a single point obviating the need for multiple supports and multiple support ropes crossing the yard. Portable End-Fed 40-6 Meters Poly-Stealth Dipole Antenna Portable End-Fed 40-6 Meters Dipole Antenna. All Band Dipole Mk2. Made out of aluminum tubing Uses PVC as an insulator Is 32 feet high Feed at the base to a SO239 connector Radials: 32 (and not all the same length - 35 feet to 20 feet) Some 100 radial pins in the lawn. For non-resonant end fed antennas, the typical feed point impedance is 300 to 600 ohms and a 9:1 impedance transformer (e. Start with the wire about an inch longer to. The lowest frequency at which a dipole is resonant is known as its fundamental resonance. The antenna was required to operate over the frequency range of 220 MHz to 225 MHz specified in the standard. Test time I mounted the antenna about ten feet off the ground in a flat-top configuration. Measurement results for the S11 (or SWR) are…. The origin is located on the X-Y plane. A log-periodic antenna ( LP ), also known as a log-periodic array or log-periodic aerial, is a multi-element, directional antenna designed to operate over a wide band of frequencies. Antenna construction centers around 50 Ohm coax. It operates without a tuner, and its SWR readings are usually at 1. The K7EFX Multiband "3-Half-Wave 6-Meter," "Half-Wave 17-Meter," Rotatable Antenna. A trap design guide is provided below to aid multiband dipole construction. Both antennas perform well given the conditions at the time. An extra bonus is that this antenna will work on 20, 17, 15, and 12 meters, although without the gain obtained on 10 meters (some people miss this part). Calculator. The antenna balun is constructed per the W. http://astore. The detailed construction drawings, sheets and. Approximately 30% shorter than a full size dipole. Notice the difference in the pattern of this antenna and the curve for the dipole in figure 2. 5-1 meter, so that the total loop length is about 1-2 meters. Antenna Round Up — antennas for 6, 10 & 2 meters Antenna Theory 101 — antenna tutorial from KD4SAI Antennas from K5DKZ Antennex — online antenna magazine Attic Antenna — trap dipole design for your attic. 1 : 1 at the middle. Here i present all steps to build this antenna. Same construction as MFJ-17758. A folded dipole is an antenna, with two conductors connected on both sides, and folded to form a cylindrical closed shape, to which feed is given at the center. A dipole design for the 20-meter band is an efficient and inexpensive antenna for the novice and veteran ham enthusiast alike. The tuner balked a bit on 17 meters and it was very touchy on 10 meters. The dimensions for the 20, 17, 15, 12 and 10 meter bands are shown in Table 1. Some gain and increased bi-directivity is achieved with this configuration. 5 for the FULL BAND on 20 meters. It's a dipole fed off center with a 4:1 current balun at the offset feedpoint. When compared to the planar dipole, the folded dipole structure increases the input impedance of the antenna. Obviously not the best antenna situation, though it has been good enough to provide me plenty of fun. Tilted Folded Dipole Antenna 16 25. All details are shown in the picture on the right. Band switching is accomplished automatically through the use of two matched Hy-Gain 40-meter Hy-Q traps. Because it would be fairly difficult to move a core like this up and down the feedline, I decided to place it at the predicted spot (0. The K7EFX Multiband "3-Half-Wave 6-Meter," "Half-Wave 17-Meter," Rotatable Antenna. The size of each wire is approximately a quarter of the wavelength of the desired frequency of operation. Dahlberg N7AGK Editors note: The author of this project arrived at these plans by experimentation so this antenna should be considered an experimental project by the builder. DXBeam DXD4030 1 Product Reviews EHam Net. 20/40 Meter Short Coax Trap Dipole Antenna. This is especially easy for making an 75-80 dipole out of a 40 meter Slinky Dipole when you don't have an antenna tuner handy. 85 : 1) though the top (1. To remedy the narrow bandwidth I used a bowtie dipole antenna for 10 meters. Mac, AF4PS, FP -51 (Note: This was installed at a previous QTH) I will be the first (or millionth, remember, I'm from FL!) to affirm that the antenna is the determining factor for success when it comes to one's station set-up. The detailed construction drawings, sheets and. 54 : 1), the SWR is dead flat at 14. Order 7-Band 100 Watt QRP (low power) OCF Dipole Antenna: $312 Special Price: $235 (6 or more = $188 ea. txt) or read online for free. Max Gain(dBi) 12. When compared to the planar dipole, the folded dipole structure increases the input impedance of the antenna. 5-inch dipole and 17 and 10 meter dipole with 3 inches. 99 shipping. The plan was to put up a one wavelength square loop for 20 meters in the diamond configuration, and a delta loop for 40 meters with a common feedpoint. Reisenauer, Jr. It is designed to have extra long. Length L(meters) = 142. This might be a good design for the AMer who lives in the central part of the USA and wants to put a better signal into both coasts with a minimum of effort. If you plan to design, build, or construct a dipole antenna yourself, the following are steps you can take to create an antenna that can function on the High Frequency (HF) bands. Cut two 14 AWG wires 17 feet long for the 20-meter elements, and two more 11 feet long for the 40-meter elements. A more recent version of the antenna cut for 40 meters uses a different ratio: This placement is believed to hit the 100-ohm point on the antenna wire, where a 2:1 balun will reduce the impedance to 50 ohms for coaxial. A 2-Meter Vertical Dipole Array, KG4JJH Page 1 of 6 A 2-Meter Vertical Dipole Array Build this 2 or 4-Element VHF repeater antenna with up to 9. These work okay and can be deployed from my patio. Input Impedance(Ω) 50. The Frequency Devices 20HWDB Half Wave Center Fed Dipole antenna with a 1:1 Current Balun is tuned to about 14. A standard half wavelength horizontal dipole operates at ninety-eight percent efficiency. A trap is as an open circuit on the higher frequency (40m), but it is a load on the lower frequency (80m). The nice thing about this fan dipole is that the middle spacer keeps the 20m section nice and tight. The antenna wire (13 feet for 17 meters and 16. Trap dipole antenna, 3 bands. TAK-tenna 40 to 10 meter Multiband Antenna Boom = 30 in/76cm; sprial radiating element = 30 in/76 cm diameter; weight = 4 Lbs/1,8Kg TAK-tenna 80 to 6 meter Multiband Antenna. This antenna may be built as a 20 meter, 17 meter, 15 meter, 12 meter or 10 meter monoband vertical antenna. The SWR is below 1. Design Goals and Objective: Construct a compact, 20 meter rotatable dipole antenna of durable weather worthy components supported at a single point obviating the need for multiple supports and multiple support ropes crossing the yard. Cut two 14 AWG wires 17 feet long for the 20-meter elements, and two more 11 feet long for the 40-meter elements. lpdipole = lpda creates a printed log-periodic dipole array antenna using default property values. Using a 3 – 12 V lightbulb we can make a symmetrical antenna. The NB6Zep antenna is a simple inexpensive wire antenna, easy to build, that will yield excellent results on all bands. If you do get RF problems in the shack make sure you have a good earth (see earlier). The multi-band antenna is a full-sized 20-meter dipole using 22 gauge stranded insulated wire. Windom W8GZ. The 40 meter length that I used is 33' 3-1/2" (10. With a 1064m2 (1/4 acre) town block with a depth of 60mtr (200') I intended to improve on my previous All Band HF Doublet with an antenna. To remedy the narrow bandwidth I used a bowtie dipole antenna for 10 meters. The G7FEK design will allow operation on 80m / 40m / 30m / 17m / 15m / 12m with the possibility to add the 20m band. Separate the speaker wire into two 18-foot lengths. However, radiation will take place on the 20-meter band if the antenna is made for the 75-meter phone band, but the losses in the stubs will rise. Now connect your transmitter (and SWR meter, if your transceiver doesn’t have one) or antenna analyzer and apply (low) RF power on the desired frequency, in this case 7. The short end was placed at about 40 feet off the ground, tied to a tree limb, using about 10 feet of insulated rope. You are now the proud owner of a Comtek 20 Meter Vertical Antenna. •Have been used to design 4 element 40M Yagi’s at top contest stations (K3LR, W3LPL, KC1XX, K4JA, K9NS, NO8D, etc. a “balanced” antenna. Searching for a half-size half-size 2-element Yagi, I found the design by Gary Hanson (KJ5VW), ref. The fields from the half-wave dipole antenna are given by: The directivity. 85 inches if you don't like the metric system). With a 75Ω match requirement this would give a VSWR of >20. Antenna construction centers around 50 Ohm coax. In fact, if you can mount a vertical on a dock over salt water, you can drop a plate into the water and establish a good, low loss system with no radials. The small mast through the roof on the left supports the top wire to the house. impedance for 20 meter dipole so all. There is some cancellation of energy on a line through the `gap' opposite the feedpoint, but it is minor in the `real' world performance. These include multiple resonant dipole arrays, trapped dipoles, resonant loops and the off-center fed dipole, OCFD. Off-Center Fed. For an 80-10 meter OCF dipole antenna, divide the 1⁄2 wavelength standard of 468 by the lowest operating frequency of 3. 40 meter operation has very high. There are a few ways to build multi-band HF antennas. A dipole has three physical points to consider. Construction Info For 30-Meter Magnetic Loop Antenna. There was no difficulty in tuning the Multi-band Trap Dipole Antenna by trimming the wire lengths starting from highest band. This is a popular antenna design as the performance is very good across the HF bands and requires little or no tuning. A SWR meter or antenna analyzer (AA-170) is required although provided. On the other hand, as a high-performance (and good gain) antenna on the 20-meter band, the antenna is hard to beat. Here are my SWR results: 10 meters: lowest at 28. Using the whip, ≈20 show. (Restricted space antenna) THE “WAVE-MISSLE” by VE1COR. A full-size ( = ½λ) dipole antenna for the 20 mtr band spans about 10 meters (33 ft). 65 – Inverted-V Beam Antenna for 30m. Mount antenna mount on bracket. A "magnetic loop" antenna, so named because it responds primarily to the magnetic rather than electrical component of a radio wave, is a very small (relative to wavelength) single-turn loop tuned to resonance with a series capacitor. Multiband Cubical Quads - EI7BA Multiband Cubical Quads projects, includes two elements quad antennas for 10 12 15 17 20 meters band. Both antennas perform well given the conditions at the time. 12 dbi 433Mhz Antenna half-wave Dipole antenna SMA Male with Magnetic bTPO T ht; unopened, 12 dbi 433Mhz Antenna half-wave Dipole antenna SMA Male with Magnetic bTPO T ht. MonoBeam Yagi MB7 The MB7 10-15-20-40 is a quad band antenna for 7 MHz, 14 MHz, 21 MHz and 28 MHz with loading coil and capacitive hat for 40m only. Professional help was required for this project, I needed well-made traps for this antenna to perform well. I put up another se­parate du­al band an­ten­na for the new bands, now that I had a rig (FT-950) that cov­ered them. An Attic Coaxial-Cable Trap Dipole for 10, 15, 20, 30, 40, and 80 Meters John DeGood, NU3E [email protected] Using a 3 – 12 V lightbulb we can make a symmetrical antenna. Concentrating energy is another way of saying the antenna develops gain. My antenna has +/- 75Khz on 75 meters, +/- 100Khz on 60 meters, and +/- 140Khz on 40 meters. Now connect your transmitter (and SWR meter, if your transceiver doesn’t have one) or antenna analyzer and apply (low) RF power on the desired frequency, in this case 7. Tilted Folded Dipole Antenna 16 25. It was invented by John Dunlavy in 1952. Can be matched to coax for single band operation. STACKED at 20 M at 10 M The Take off angle (A and C see fig) 9 degrees 8 degrees 14 degrees the gain 15,5dBD 13,55 dBD 13,02 dBD the front to back 22 dB 45 dB 45 dB the Front to side 13,7 dB 12,6 dB 12,6 dB Below are the two individual antenna diagrams the first from a 5 elements at 10 meters the second at 20 meters. For example, for the 2. 48m] dipole. The struggle for a good 20-meter antenna. The antenna’s low cost is made possible by modifying a RadioShack FM broadcast receiving antenna (RS 15-2163). As the name suggests, the length of the antenna is about half of the wavelength of the frequency the antenna is cut for. You are now the proud owner of a Comtek 20 Meter Vertical Antenna. An STL can be used on 20 meters and above, and I’ve done that. Both antennas perform well given the conditions at the time. Re-using my previous RG-174, 30-meter antenna, I dismantled it to install a toroid-choke. Max Input power(W) 60. A "magnetic loop" antenna, so named because it responds primarily to the magnetic rather than electrical component of a radio wave, is a very small (relative to wavelength) single-turn loop tuned to resonance with a series capacitor. This antenna consists of two wires (or traces on a PCB board). 25 PVC pipe (Coil Lenght +2″ = 3. The arms must be separated, so the braces will give structure to the antenna. With the antenna located (Will work just ground g take, type Of Sloper a That because it i 3 a. The input impedance of the half-wavelength dipole antenna is given by Zin = 73 + j42. After looking at articles in the ARRL Antenna Book and on L. The antenna is a short, base-loaded dipole. All readings were taken with a Array Solutions AIM-1470b Antenna Analyzer. , for the 20-17-15-12-10 meter band (ref. The Delta Loop is not only a great transmitting antenna but a low noise receiving antenna. Measurement results for the S11 (or SWR) are…. The resonant point of the 3rd harmonic of the 40-meter element has been shifted lower through the installation of capacitance-hats resulting in the SWR being below 2. It has the effect of lowering the overall length of the antenna, allowing me to fit the entire span of the antenna on the side fence. 070 MHz= 16' 7. Now comes the time to connect the antenna wire/counterpoise. 1 at lowest point), for ALMOST the FULL BAND on 40 Meters, and under 1. Consequently, through all this my wife (N8YZI of 27 years) now thinks I have totally lost my mind, but I think I’ll leave my 30 meter inverted vee antenna up for a while. STACKED at 20 M at 10 M The Take off angle (A and C see fig) 9 degrees 8 degrees 14 degrees the gain 15,5dBD 13,55 dBD 13,02 dBD the front to back 22 dB 45 dB 45 dB the Front to side 13,7 dB 12,6 dB 12,6 dB Below are the two individual antenna diagrams the first from a 5 elements at 10 meters the second at 20 meters. 20 Meter Dipole at 20 feet. Note fishing snap swivels for far-end attachment to halyards. Design the 20 meter Trap using the Coax Trap Calculator. Off-Center Fed. Ultimately, I ended up with an antenna. But a dipole at 20 meters is more than 10 meters wide. 668 m) for the 40 meter elements and 5' 4-1/2" (162 cm) for 80 meter elements. It is made to be hung in the rafters or from the ceilings. You'll also find here many innovative new Accessories for hf/vhf portable antennas. antenna with 3db gain over a dipole Formula: L ft = 1170/f MHz Feed with open wire line and a tuner, this antenna will function on 20-6 meters May need 6 meter tuner (easy to build) since some tuners, especially auto-tuners, may have a limited matching range on this band. MFJ-2104$ 269. End insulator to Loading coil 5 feet, 4 inches. STACKED at 20 M at 10 M The Take off angle (A and C see fig) 9 degrees 8 degrees 14 degrees the gain 15,5dBD 13,55 dBD 13,02 dBD the front to back 22 dB 45 dB 45 dB the Front to side 13,7 dB 12,6 dB 12,6 dB Below are the two individual antenna diagrams the first from a 5 elements at 10 meters the second at 20 meters. With a tuner, you are also supposed to be capable of using some of the WARC bands. 6 MHz and you arrive at an overall length of 130′. It covers the entire 40 meter band with a SWR of less than 1. 1 Falcon 60 Meter 1/2 Wave Dipole Amateur Ham Radio Antenna. Vertical Dipole Anchors At Base Instead of installing the dipole horizontally, you install it vertically with one end about 2-3 ft off the ground using a rope (ideally with a pulley) to support the. Using 100 watts on 75/40 and 50 watts on 60 meters, this antenna will work very well with very good efficiency because it is a tuned dipole. At the Club’s ( N1FD) recent VE. End-fed HF antenna matchbox that is quick and easy to setup and use. 5' sop make your dipole legs about 8' 10". Sure enough, my antenna tuner was able to load it on all bands from 40 through 10 meters--more or less. Heat gun (or other way to activate the heat shrink). the 10-meter band (28-29. The antenna height (H) above terrain should be 20 feet minimum. For an 80-10 meter OCF dipole antenna, divide the 1⁄2 wavelength standard of 468 by the lowest operating frequency of 3. Home-Made Magnetic Loop Antenna for 30 Meters. Top wire for lowest band frequency (80 meters), determines overall antenna length. Bill's NVIS dipole is constructed much as presented below, and is 10 feet above ground. 2-1 swr on 40m. Roberts design as specified in the ANSI C63. The coil feed wire is 14 inches in length. These bands were somewhat arbitrarily chosen, as any amateur band from 160m through 2m can readily be supported. It looks like the length L of each folded dipole is somewhere between 0. Using 100 watts on 75/40 and 50 watts on 60 meters, this antenna will work very well with very good efficiency because it is a tuned dipole. Now, I’ve come up with a longer, lighter and more compact (when disassembled) antenna that is easier to build, and easier to find parts for. pdf), Text File (. It operates without a tuner, and its SWR readings are usually at 1. The antenna can be ordered for any frequency from 30 MHz to 174 MHz. A standard half wavelength horizontal dipole operates at ninety-eight percent efficiency. Off-Center Fed. The antenna can be seen as a dipole except that the feed point is placed at the end (or beginning) of the wire. A dipole design for the 20-meter band is an efficient and inexpensive antenna for the novice and veteran ham enthusiast alike. Dipole Antenna Calculator. I currently use only wire antennas which work fine on 40 and 80 meters, but on the higher Bands, I need some gain. This antenna consists of two spirals, BALUN and feed line. However, as a 20-meter vertical dipole is about 33 feet high, this would still be outside my design parameters. Top wire for lowest band frequency (80 meters), determines overall antenna length. pdf), Text File (. amossector = sectorInvertedAmos creates an inverted Amos sector antenna with four dipole-like arms. 4% around frequency carrier. And that’s all there is to it! This is a great first antenna! Your next step, after getting some air time, will be to insert some traps in that dipole so you can use it on 20-meters. The struggle for a good 20-meter antenna. 15 dBi (3 dB + 2. 4 GHz 2 dBi Wi-Fi rubber ducky antenna design; left — the assembled antenna, middle and right — the disassembled antenna. Build the 20 meter Coax Trap Step 1. Finally, a mast mount version of the 11 meter "collinear" CB antenna is available. Length L(meters) = 142. Concentrating energy is another way of saying the antenna develops gain. A horizontal 20 meter band dipole at 10m height. The 40 was resonant over a very narrow bandwidth and probably took 20 cycles to get it close. It received well on both bands. On 17 meters the NB6Zep Jr. Weighs approximately 4 ounces. During what turned out to be an extended tower-raising project (Going from 55 feet to 90 feet), I had my beam down and I needed an antenna that could provide the necessary gain and angle of radiation to talk to my friend Skip down at the South Pole. Prototype # 1 was a "Dual Band" (40 -20 Meter) Parallel Dipole Antenna, each Dipole is a "Cage Dipole" SWR was BELOW 2. Note 2: Dipole mounts are secured with 1/2" by 1/2" angle bracket or other means to end of each arm, on top of arm end, as shown. Both soldered dipole halves needs to be driven into the plastic tee fitting. 0 turns show above the contact ring. Aug 24, 2017 - An Attic Coaxial-Cable Trap Dipole for 10, 15, 20, 30, 40, and 80 Meters. Only a dipole would be easier to construct and maintain. On the other hand, as a high-performance (and good gain) antenna on the 20-meter band, the antenna is hard to beat. 070 MHz= 16' 7. 5:1 ERP = 199 W at 85 degrees 30 deg -3 dB = 99 W F/S at 30 deg -5. Government. The length of the antenna (in meters) is 100 divided by the desired lowest frequency in MHz. Folded dipole design. ost commercial 2-meter repeater antennas with gain fall into two categories: collinear arrays and stacked element arrays, with gains ranging from 3 to 9 dB1. Because a good, horizontally-polarized, omnidirectional antenna is rather difficult to construct, we held. I avoided using this antenna on six since at first I had the dipole and later a Moxon followed by a 3-element Yagi. Weather Tight Indoor Outdoor Design. Ground type is assumed to be "moderate" (conductivity and dielectric constant). In one aspect, an apparatus is described that includes a transparent pane having a first surface and a second surface. 99, plus tax, you get a 70. 1 on my SWR meter from 21. 175 MHz (the center of the 20 Meter ham band). 6 MHz and you arrive at an overall length of 130′. Dipoles are. Hence, the half-wavelength dipole antenna's length is 0. Likes Received: 206. Figure 1a – Front and side views of the vertical dipole antenna. 33 ft 9 in long b. It was invented by John Dunlavy in 1952. Ifan antenna has a gain ofO dBd, Dip. On 15 meters and above, multiple lobes are produced as shown in the diagram below. The ends and the supply. End insulator to Loading coil 5 feet, 4 inches. Searching for a half-size half-size 2-element Yagi, I found the design by Gary Hanson (KJ5VW), ref. The only Mod I made to it other than personal choices of similar. Since the element is currently 28' 10" long, I need to add another 34' 6" feet to it. Overall length is 82 feet. Cut two 14 AWG wires 17 feet long for the 20-meter elements, and two more 11 feet long for the 40-meter elements. Portable End-Fed 40-6 Meters Poly-Stealth Dipole Antenna Portable End-Fed 40-6 Meters Dipole Antenna. Thread each 20-meter element through a crimp sleeve (or other strain-relief device), through one of the balun eye bolts, then back through the crimp sleeve. There is some cancellation of energy on a line through the `gap' opposite the feedpoint, but it is minor in the `real' world performance. Shortened 40 meter dipole shown with OPTIONAL "BL 10-160-5KW" Balun. 12 dbi 433Mhz Antenna half-wave Dipole antenna SMA Male with Magnetic bTPO T ht; unopened, 12 dbi 433Mhz Antenna half-wave Dipole antenna SMA Male with Magnetic bTPO T ht. So using iterations, it is possible to use the antenna at lower frequencies without increasing antenna size. 0} number of Elements must be between 3 and 20 elements; tau (shortening factor) sigma (separation factor) length of dipole 1 (largest one in meters) element radius Type (1 means fixed; 2 means fixed radius/length ratio). That does not fit every home or garden. 5 on all the bands. W2VS traps are available for 80 meters and up in two versions. The origin is located on the X-Y plane. To accomplish this feat it uses something familiar to any sailor: a capstan. This antenna may be built as a 20 meter, 17 meter, 15 meter, 12 meter or 10 meter monoband vertical antenna. The ends and the supply. No other omni directional CB antenna can come. MFJ-2104$ 269. Now to make that dipole work efficiently you will need to make sue it has equal distribution of current in each leg, I. It shall be easy to adjust (i. The NB6Zep antenna is a simple inexpensive wire antenna, easy to build, that will yield excellent results on all bands. With the antenna located (Will work just ground g take, type Of Sloper a That because it i 3 a. Ground type is assumed to be "moderate" (conductivity and dielectric constant). 85 inches if you don't like the metric system). The input impedance of the half-wavelength dipole antenna is given by Zin = 73 + j42. V/m = Volts per meter. The 40 was resonant over a very narrow bandwidth and probably took 20 cycles to get it close. I did make some changes from the original design to the lengths of the antenna elements. Re-using my previous RG-174, 30-meter antenna, I dismantled it to install a toroid-choke. 67 – Half-Sloper Antenna for 160m. The narrowing of the lobes concentrates the energy radiated by the antenna. When connected to a tuner, the antenna works on 6, 15, 30, and 80m bands more efficiently than the original G5RV. Consequently, through all this my wife (N8YZI of 27 years) now thinks I have totally lost my mind, but I think I’ll leave my 30 meter inverted vee antenna up for a while. The Infamous Attic Dipole. •20 meters and above or 80 meters and All band dipole type antenna TV antenna 20 mtr 40 mtr 80 mtr. 6 MHz and you arrive at an overall length of 130′. The an tenna is standing in the Z. This dipole antenna consists of a matching balun, two telescoping elements, balun clamp for mounting, and a tape measure to adjust the element lengths. Gain F/B Zin SWR Zin Freq. 2 MHz 2:9 14. DX-CC - “No-Trap” 80-40-20-15-10 meter dipole or inverted-V. 1 Falcon 160-10 Meter Off Center Fed Dipole Amateur Ham Radio Antenna. The measurements below are for building a simple Dipole Antenna. lpdipole = lpda (Name,Value) sets properties using one or more name-value pairs. 48m] dipole. I tuned the antenna at an unused repeater input frequency near 146. The bandwidth of the antenna is about 1:5. I built the dipole and did some testing using my K3’s built-in SWR meter. The 40 meter dipole is fed with coax (not the most efficient feedline but it works)with no balun. the 10-meter band (28-29. 4 GHz ISM band with a wavelength of approximately. For example, amossector = sectorInvertedAmos ('ArmWidth',0. A few of those cycles, I wore a GoPro camera on my combat tactical helment mount where the night vision normally goes. By matching the antenna through a L/C impedance matching L network, the SWR could be lowered to less than 1. Cut two 14 AWG wires 17 feet long for the 20-meter elements, and two more 11 feet long for the 40-meter elements. Both antennas perform well given the conditions at the time. There was no difficulty in tuning the Multi-band Trap Dipole Antenna by trimming the wire lengths starting from highest band. Log Periodic Dipole Arrays, or LPDA is a directional antenna with relatively constant characteristics across it's wide frequency range. Because it would be fairly difficult to move a core like this up and down the feedline, I decided to place it at the predicted spot (0. These bands were somewhat arbitrarily chosen, as any amateur band from 160m through 2m can readily be supported. When stacking dipole antennas in such a fashion, doubling their number will, with proper phasing, produce a 3 db increase in directive gain. Dahlberg N7AGK Editors note: The author of this project arrived at these plans by experimentation so this antenna should be considered an experimental project by the builder. Strip 1/2 inch of insulation from both ends of each wire. 63 – Wire-Beam Antenna for 80m. 56 dBi down from optimum) and near vertical radiation pattern, we have an NVIS cloud burner. Tilted Folded Dipole Antenna 16 25. With the dipole facing North and South, 5x9 reports were received from as far as Argentina, South America. 1 Falcon 160-10 Meter Off Center Fed Dipole Amateur Ham Radio Antenna. 000 17 meters: less than 1:5 entire band 20 meters: less than 1. On the other hand, an OCF dipole is an ungrounded dipole antenna fed with twin-conductor line, either coaxial or open wire parallel conductors. 100 MHz trap would be needed. 150) which equals 64′ 5″. 5 standard and consists of a folded balun that converts the 70-ohm (at resonance) to 50-ohm impedance. Trap L1C1 turn off upper antenna. It's the base line. The NB6Zep antenna is a simple inexpensive wire antenna, easy to build, that will yield excellent results on all bands. Overall length is 82 feet. Using the whip, ≈20 show. DX-CC - “No-Trap” 80-40-20-15-10 meter dipole or inverted-V. That sounded fine to me. The exact frequency was unimportant. Hold the lightbulb and touch the folded dipole, move from end point to middle. * La = 145 / freq ( MHz ) Length of coil. It’s a random wire antenna and it isn’t resonant on any band which is why you can use it from 40 to 6m and on all bands. Input Impedance(Ω) 50. Rated for 2KW PEP. The feed point of the dipole coincides with the origin. An electrochromic device is arranged over the second surface that includes a first conductive layer adjacent the second surface, a second conductive layer, and an electrochromic layer between the first and the second conductive layers. Ham Radio, Amateur Radio - Short coax fed 42 foot long dual band 40/20 Meter dipole antenna. 2-meter Yagi—complete with mounting hardware—for $20. 61 – Tri-band Delta Loop Antenna for 80m – 40m – 30m. The narrowing of the lobes concentrates the energy radiated by the antenna. With a 1064m2 (1/4 acre) town block with a depth of 60mtr (200') I intended to improve on my previous All Band HF Doublet with an antenna. Strip 1/2 inch of insulation from both ends of each wire. Assembling the 20 Meter Antenna Matchbox For the popular 20 meter band, a suitable inductor can be made with 26 turns of enamel coated # 22 copper wire wound on a T80-2 toroid as pictured on the lower left. End insulator to Loading coil 5 feet, 4 inches. See full list on hamradiosecrets. The HyEndFed multiband Antenna is an antenna for 5 bands 80, 40, 20, 15 and 10 meters amateur band. Notice the difference in the pattern of this antenna and the curve for the dipole in figure 2. Operation is also enabled on 15 meters, because it is a third harmonic of 40 meters. 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. Description: Band coverage : 40 & 20 meters amateur bands Total constructed Length : 53' feet Power Handling : 1,500W + SWR : < 1. IS NOT TO SCALE!. 20/40 Meter Short Coax Trap Dipole Antenna. Parachute cord is used at the ends of the 17 meter dipole to tie it off to the 20 meter dipole above it. Circular dipole antenna 600W - tunable. On 17 meters the NB6Zep Jr. The origin is located on the X-Y plane. The Moxon Rectangle I started thinking of putting a simple rotat-able dipole at the top of my HF roof tower. The size of each wire is approximately a quarter of the wavelength of the desired frequency of operation. 5-1 meter, so that the total loop length is about 1-2 meters. SWR is below 1. On the other hand, an OCF dipole is an ungrounded dipole antenna fed with twin-conductor line, either coaxial or open wire parallel conductors. 4 GHz Dipole Antenna with Reverse TNC Plug. Top wire for lowest band frequency (80 meters), determines overall antenna length. W2VS traps are available for 80 meters and up in two versions. He is credited with original article in QST magazine. That said, you will need two 10' sections on 10 meters, two 13' sections on 15 meters, two 18' sections on 20 meters, two 35' sections on 40 meters or two 70' sections on 80 meters to build a half wave dipole antenna for your band or bands of choice. End-fed HF antenna matchbox that is quick and easy to setup and use. At the Club’s ( N1FD) recent VE. Magnetic Loops. 2 meter vertical dipole array 1. 54 : 1), the SWR is dead flat at 14. emission pattern from a dipole antenna. Strip 1/2 inch of insulation from both ends of each wire. (Restricted space antenna) THE “WAVE-MISSLE” by VE1COR. All well and good if you want to just oper-ate on one portion of one band, but what if you want to operate with the same antenna on different. In the summer 2008, I homebrewed a double bazooka dipole antenna (a) for 15m band because I was expecting and was hoping that the condition was becoming better. Being an amateur radio operator and an HF shortwave crystal set enthusiast, it accrued to me that it would be fun and doable to design a 20 & 30 or 20 & 39 meter vertical antenna, featuring a coaxial trap to isolate the 20-meter portion. The antenna was designed for military use from 2 to 10 MHz (some references say 2 to 30 MHz). These work okay and can be deployed from my patio. Here are some comments from VE3BF: Build an easy and inexpensive portable antenna for 20 meters and other bands. 00 15-10 Meter W7FG True Ladder Line Open Wire Fed Dipole 22' Dipole 50' Feedline $61. Now you have an automatic bandswitching 5-band dipole!. Simple dual-band (40-20) dipole antenna Testing the result At last, it was time to take some measurements, and hope that my calculations weren’t too far off. Off-Center Fed. End insulator to Loading coil 5 feet, 4 inches. The Infamous Attic Dipole. Same construction as MFJ-17758. 5, 4, 6, and 10 meters (8, 13, 20, and 33 ft). Octopus antenna hub turns your ham-sticks into four fully balanced dipoles in minutes! Mix and match any four HF/VHF/UHF bands. 1 piece antenna. Sometimes on 80 meters but there the 80 meters 2 * 20 meter dipole fed with open wire gave me more qso’s. That does not fit every home or garden. Bill's NVIS dipole is constructed much as presented below, and is 10 feet above ground. pdf), Text File (. For example, amossector = sectorInvertedAmos ('ArmWidth',0. On 20 meters the antenna is a double zepp wire or a 1 wave dipole. Prototype # 1 was a "Dual Band" (40 -20 Meter) Parallel Dipole Antenna, each Dipole is a "Cage Dipole" SWR was BELOW 2. Now, I’ve come up with a longer, lighter and more compact (when disassembled) antenna that is easier to build, and easier to find parts for. The direction of fire is broadside to the antenna. A dipole works best at and above its fundamental-resonant frequency. TAK-tenna 40 to 10 meter Multiband Antenna Boom = 30 in/76cm; sprial radiating element = 30 in/76 cm diameter; weight = 4 Lbs/1,8Kg TAK-tenna 80 to 6 meter Multiband Antenna. Antenna may be made practically from any wire (strand, solid) having a reasonable diameter- 0. 20m Vertical Dipole. Rather than attempt to design a coaxial dipole from first principles I decided it would be easier to build one and îreverse engineer it. W2AU Balun in place. Top wire for lowest band frequency (80 meters), determines overall antenna length. 5 for the FULL BAND on 20 meters. 250 MHz) to get 32. However many apartment dwellers have operated using whips installed on their balconies. 0-1 swr, on 40m it won’t but if the center of the antenna is raised to 30″ the swr will be less then 1. 6 MHz of the 80/40/20 m RC-Dipole at 7 m height over poor ground. However, as a 20-meter vertical dipole is about 33 feet high, this would still be outside my design parameters. THE DRAWING. In my opinion, it's a work of art! All I did was make spacers out of 1/2" PVC tubing the wire is spaced 6" off center. The an tenna is standing in the Z. On the other hand, as a high-performance (and good gain) antenna on the 20-meter band, the antenna is hard to beat. It's an 1/8 wave vertical on 160 meters also. Has a length of 34 feet (10. SWR is below 1. Improved All Band HF Doublet was constructed and refined from the experience from my previous All Band HF Doublet for use with a Z-Match Antenna Matching Unit. The most common form of log-periodic antenna is the log-periodic dipole array or LPDA, The LPDA consists of a number. Below are SWR plots for the five bands this parallel dipole is resonant. The fields from the half-wave dipole antenna are given by: The directivity. 25 MHz, halfway between the 144. The lowest frequency at which a dipole is resonant is known as its fundamental resonance. 250 MHz) to get 32. The antenna offers a gain of about 10 dB, is lightweight, mechanically strong and rivals the performance of similar commercial antennas. 1500 to 2400 Watts Maximum Legal Limits. My antenna has +/- 75Khz on 75 meters, +/- 100Khz on 60 meters, and +/- 140Khz on 40 meters. 000 17 meters: less than 1:5 entire band 20 meters: less than 1. e tuned feeders (high SWR). 6 MHz of the 80/40/20 m RC-Dipole at 7 m height over poor ground. 95 * 1/4- wavelength from "center") and. DIY 5$ Portable VHF Yagi Antenna for the 2 Meter Band (144-146 MHz) by F4HWK: In this publication i explain how to build a very light weight, cheap, easy to build and deployable in 30 seconds portable VHF antenna for the 2 meter band. 1 at lowest point), for ALMOST the FULL BAND on 40 Meters, and under 1. 10 Through 20 Meter Vertical Dipole (With a novel matching method) By KL7JR John F. The exact frequency was unimportant. However the antenna is work and may be used in tight conditions. The length of the dipole is half of the wavelength. Design Parameters. 6 Meter 5/8 Wave Vertical Antenna By Mike, G3JVL- link How to Build a Six Meter Ham Radio Dipole Antenna by K7AGE- Youtube 6 meter, 2 element yagi- A simple, compact and effective antenna for 50 Mhz. 4 , 9 MHz, 12. The purpose of this build was to replace my 12/6-Meter inverted-vee with a rotatable antenna. 25″ coil form off the 1. For example, for the 2. This horizontal “slot” antenna, cut into the reflector of a TV dish, is both the master of disguise and high in performance. Log Periodic Dipole Arrays, or LPDA is a directional antenna with relatively constant characteristics across it's wide frequency range. Pic: 17 3D total gain pattern at 3. On 20 meters, the 88 foot length dipole produces about 3 db gain over a similar height 1/2 wave dipole. The SWR is below 1. The DOUBLE BAZOOKA antenna design was first conceived as a radar antenna in the early 1940's for use by the U. Drill the bracket. Refer to Figure 3 for the dimensional key. On the 80 meter band, the same antenna has just a small amount less gain than a full size 1/2 wave length dipole at the same height. The reason why this antenna type is so popular are probably the following: The length is "only" about 5,50 meters This antenna does not require any radials Easy to erect! To construct this antenna most use black markings on the aluminum to judge the length and give the user a satisfying S. When connected to a tuner, the antenna works on 6, 15, 30, and 80m bands more efficiently than the original G5RV. A windom antenna is a single-wire-fed antenna which is worked against ground. 17/30 Meter Dipole. The overall length of the antenna is 76' (22' for each doublet leg plus 54' of feedline) so this antenna should be easy to tune on 10, 15, 20, and 40m. The antenna can be seen as a dipole except that the feed point is placed at the end (or beginning) of the wire.