Cigar Box 6 Watt Output Transmitter. Let's Build One! The NVIS antenna described is based on the proven information from the military AS-2259/GR antenna. Building A 2-meter J-Pole Antenna. 40 meters on a 80 meter di-pole!), so you may want to double check that before using a balun. A 2 meter version. The homebrew J-Pole I was using would be okay, but it was limited to the 2 meter band and some of the repeaters in the area are in the 70 centemeter band. 8 out of 5 stars 3. The cost savings was just enough to speed things along. AN ALL-COPPER 2-M J-POLE Rigid copper tubing, fittings and as-sorted hardware can be used to make a really rugged J-pole antenna for 2 m. It’s modeled after the basic delta loop design and is fed with a 1/4 wavelength of 75 ohm coax (RG-59U). Modified Aluminum Dual Band J Pole ('Arrow') Antenna for Fiberglass Body Mini RV By KK6VLV. After searching the internet for a homebrew antenna, I stumbled upon this interesting antenna called "screwdriver antenna". Diamond ® Antennas are sold through authorized dealers. We thought some of you may be interested in it. •Need lots of room, keep them away from metal objects like heaters and ducts •Wire antennas can be run near the peak of the roof inside the attic, bent in odd shapes to match the space available. I used a dual band hand held radio as a signal source and a Kenwood VHF/UHF power and SWR meter as a tuning indicator. 2 meter collinear j- pole Pembuatan Antena ini tidaklah sulit, karena hanya terdiri dari beberapa potong Pipa PVC sebagai penopang dari Element Antena yang terbuat dari pipa Aluminium dia. AMECO AC-1 With a 6V6. 2m Projects - Omnidirectional Antennas Here is a 2 meter (146 Mhz) J-Pole antenna that is inexpensive, and easy to build. This new antenna has a 1:1 toroid balun and a SO. 52 MHz 146 MHz 446 MHz 915 MHz. This makes a great emergency antenna. 2 meter collinear j- pole Pembuatan Antena ini tidaklah sulit, karena hanya terdiri dari beberapa potong Pipa PVC sebagai penopang dari Element Antena yang terbuat dari pipa Aluminium dia. Built a home brew J-Pole antenna. It rolls up and fits into the bag with no problem. ROLL-UP J-POLE ANTENNA, 6-METER: $34. Remember that an antenna is also your first filter/preselector! After several years of contesting the 20m band appears one of our most successful bands, with the 5/8 wave vertical antenna being a crucial part of this success. This one was also waiting for a PVC cover so it could be mounted on a pole. 7 dBi gain and 18° Vertical Beamwidth. Wire versions are usually the answer. The homebrew J-Pole I was using would be okay, but it was limited to the 2 meter band and some of the repeaters in the area are in the 70 centemeter band. A Super J-Pole Antenna for the 70Mhz (4m) Amateur band. Being made of copper pipe they are heavier than commercial aluminum antennas but they work The J-pole antenna, also called the Zepp' antenna (short for Zeppelin), was first invented by the Germans for use in their lighter-than-air balloons. J-pole Antenna. Schematic fig1. This is the hairpin match I made for a 6 meter yagi. The dimensions shown in Figure 2 produce a radiation pattern with low sidelobes and backlobes over the entire 2 meter band. Hams are (were) always trying new "stuff" it is more old school home brew ham rather than new buy it out of the box. Ask Question Asked 5 years, 6 This is a great starter antenna that can be handheld without being too unwieldy, and while it. DX-antentannas. In my design I use 1/2" copper schedule M tubing and 1/4" soft copper tubing. I used a dual band hand held radio as a signal source and a Kenwood VHF/UHF power and SWR meter as a tuning indicator. Only at eHam. Contact one of your local Diamond ® Dealers for current price & availability. For the same gain and EASY install and tuning, I like a mobile adaptor and a maxrad 3 db gain mobile antenna. PSU for Amateur Radio from Computer. On most of the J Pole designs out there, a choke should be used as close to the feedpoint of the antenna as possible to help prevent rf on the feedline and creating difficulty with SWR readings. 6 Meter 52Mhz J Pole rollup antenna with 16ft. J-Pole Antenna for 433 MHz ATU for the 6- meters. Amateur Base Antennas : MFJ-1895 Moxon 6 Meters, 10 Meters, 15 Meters. That should be an interesting project. 2 meter corner reflector I experimented with. Tiger Tail (walkie talkie boost) 2 meter portable roll-up J-Pole; 6 meter Rubber Duck for SEM 52 military radio. This shortened easy-to-build vertical, with no-radials, is made from surplus military camouflage poles. A Super J-Pole Antenna for the 70Mhz (4m) Amateur band. The inductor on the CB antenna makes the antenna electrically longer than its actual radiator length. The design would theoretically provide an impressive 9db gain (a claim that has generated some debate online) over the discone antenna I was using at the time. Got it in the air and on the air in time for a local 6 meter net. Bruce is right on. Wire versions are usually the answer. 40 meters on a 80 meter di-pole!), so you may want to double check that before using a balun. Alternative Method. I have enough material to make one more UHF antenna. 2 Meter Break-a-Way Slim Jim Antenna 2 Meter J-Pole, I built one of these and it was my first antenna, which still get used. It is totally UV protected and should last easily 10 years on a repeater mountain top. This month I decided to build a 2 meter 5/4 wave antenna. Some TIPS on measuring VSWR and troubleshooting M2 … Antenna Gain: dBi vs. The J-Pole is an older antenna design that’s been around a while, but not widely used or thought of these days. On vhf you can easily design a single feed 2 and 6 meter antenna. Super J-Pole Antenna This antenna was developed by the Independent Repeater Association in Des Moines, Iowa, for use on its many repeaters, nodes, and BBS. 90 - Double-Delta Antenna 80m and 40m. 000 visitors I closed www. I have been itching to get on 6 meters for years for many reasons. Antenna gain is measured in either dBi or dBd. I used a dual band hand held radio as a signal source and a Kenwood VHF/UHF power and SWR meter as a tuning indicator. It is important to note that …. By John Portune W6NBC. "Local" in Crosby, North Dakota, means 50. 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. The JK401 is a simple Hi-Q coil loaded rotatable dipole, with a small footprint as well giving great performance on 40M. SWR on two meters will be high. The detailed construction drawings, sheets and. Stripping off the 10. that the readership would possess a wide range of levels of antenna sophistication, from the novice “newbie” to the professional engineer. I could hear the moderator and lots of attendees but I could not join the net. In the first set of plans, the feed point is approximately 20% up from the shorted end of the matching stub. That assumption proved to be correct as I have received letters from a wide variety of people. 20-Meter "J" Pole Vertical. A 2 meter version. 6 Meter Half Wave Dipole Antenna with W2FMI 1500 Watt Balun. The SlinkTenna is a compact, quick deploy, portable, Helical Dipole ham radio antenna system. 7 Element VHF High Gainer N. The impedance of this antenna is around 300 Ω, so you may want to use a transformer or a λ/4 long piece of 120 Ω coaxial cable to match this impedance to 50 Ω. Handmade Slim Jim Antenna's by N9TAX Let me start by saying that since discovering the slim jim antenna design I have really come to respect these antennas. Building A 2-meter J-Pole Antenna: Design your Own Super J-Pole: Emergency J-Pole Antenna: J pole antenna per 50 Mhz, IK1ZOY: J-pole 144-146 Mhz, I0FPP: J-pole 144Mhz, I5BHN: J-Pole Antenna Design: J-Pole Antenna: J-pole antennas for 2m-40m with Wireman-cable, DK7ZB: J-pole broadcast fm 89mhz: J-pole 145 mhz,VHF antenna: Slim JIM 145mhz, F1RFM. Performance is equal to a J-pole, but it's smaller, less obtrusive and more weatherproof. Pedestrian mobile magnetic loop antenna for 40 to Field Antenna for 40m. The photo to the right is an example of how the antenna may be supported with minimal holes or damage to the wall. The traditional Super-J shows 1. Mount the antenna on a pole about 6 feet long and fasten to a step ladder or some support with some rope or electrical tape. Our UHF Slim Jim Antenna delivers up to 6dbi of gain on the 440 - 470 Mhz UHF bands, which is almost twice the gain of a J-Pole and 5 times the gain of a 1/4 wave ground-plane antenna. Omnidirectional. Home-brew Compact 6dBi Collinear Antenna. A J-pole is a balanced antenna, but a balun is not really necessary. We thought some of you may be interested in it. I built one of these antennas. A 2m colinear Super J-pole made from a 102. Homebrew Hex Wire Beam Antenna I put together a homebrew wire beam based on the "hex" style. CB is 11 meters, so the inductor obviously adds too much electrical length for 6 meters. Now you've probably heard of a beam antenna, and maybe you've heard of a J-Pole. The Wire Size can range from 16 AWG to 12 AWG. The design would theoretically provide an impressive 9db gain (a claim that has generated some debate online) over the discone antenna I was using at the time. Tuning the COM-20VA 20 Meter Vertical Antenna is straightforward and intuitive. To support the antenna, lash it to a piece of PVC pipe with UV-resistant nylon cable ties. I needed something with a wider bandwidth and dual-band. Popular 2-meter band & Antenna videos homebrew 2 meter ground plane antenna How to Make a 2 meter J-Pole Antenna with the Buddipole. Homebrew Ham Projects. Many thanks!. Cigar Box 6 Watt Output Transmitter. MY BIG VERTICAL ANTENNA PROJECT This memorandum describes my Fall antenna project, specifically a DX-Engineering, Model DXE-MBVE-1, 43 foot mono pole vertical antenna. •Many types of antenna can be mounted in the attic IF you don’t have Radiant Barrier (Tech Shield). This is a basic balun for a wire antenna, and it worked great for the flagpole! Amidon 200. This antenna is unique in that it is enclosed entirely in 3/4" PVC which makes the design a little more complicated. The silver I'm refering to is what a/c tech's use to solder. Yagi; Cheap Yagi Antennas for VHF/UHF; Halo antenna for 70Mhz; Halo for 6 meters band; J-Pole. On vhf you can easily design a single feed 2 and 6 meter antenna. 2012 nick: consschenso 10 meter whip homebrew The 10-meter band is a favorite ham hangout, commanding a wide range of homemade. A combination of antenna designs, namely the J-Pole and Zepp along with matching network technologies, are utilized to achieve a resonant antenna design on 6, 10, 15, 20, & 40 Meters and a fairly resonant pattern on the rest of the HF bands, including 80 & 160 Meters. net is a Web site dedicated to ham radio (amateur radio). Known as the Magic Band, the six meter band can be mysterious, unpredictable, and downright fun. This antenna was featured in the Feb. lead-in coax with PL259 male. 40 meter amateur bands using a good tuner without modifications for the Ohio State Parks On The Air contest. PCS Electronics. I have created a new j-pole antenna for use with the ICOM 2200h and have also added it into its go kit. •Many types of antenna can be mounted in the attic IF you don't have Radiant Barrier (Tech Shield). But what's a J BEAM? It's a vertical directional antenna made of 1/2 inch copper pipe and wood or PVC. Restraints Imposed by Location and Other Factors: I have a rather small suburban back yard, 100 feet wide (N-S) and 55 feet deep (E-W). I have not seen it on the internet so here it is for you to try! I personally have not tried this antenna but it should work fine if you follow the very simple directions! It can be built as is for 2 meters, or you can try it on other bands or frequencies with the formulas provided by me below. One for 160 through 6 meters, the other for V/UHF. Antenna Construction The dimensions for the 20, 17, 15, 12 and 10 meter bands are shown in Table 1. Bruce is right on. The ARRL Antenna Book. A 2 meter j-pole will receive most VHF & UHF frequencies fairly well and you can make it with copper tubing. 5 (11244 / 146) = 38. It's modeled after the basic delta loop design and is fed with a 1/4 wavelength of 75 ohm coax (RG-59U). Plus the antenna also have the great low noise floor and wide bandwidth typical of our other antennas. Communication. Unfortunately, no further action was heard and gone outdoors for other activities that day. Before I built any home-brew mobile VHF antennas, the only VHF mobile antenna I had was an MFJ-1724B Magnet Mount Mobile antenna. amateur radio band. I needed something with a wider bandwidth and dual-band. Anybody can throw money down,if they have it, but the whole spirit of amateur radio is experimenting and what is any easier to do that than with antennas. However shorter verticals (e. I would like to add that a J-pole would be an excellent base antenna. •Many types of antenna can be mounted in the attic IF you don’t have Radiant Barrier (Tech Shield). Antenna gain is measured in either dBi or dBd. It is an outstanding performer, especially when you get it up in the air. This is my first home brew “DIY” antenna for use on local 2 meter repeaters and simplex frequencies. Wire length in Collinear J-Pole Phasing Coil. If you use an SWR meter or an analyzer at the base of the antenna you will get the most accurate readings in a timely fashion. I just tapped the half wave and the stub starting at the tip of the crappie pole. Obviously, that particular meter, though fine for HF and okay on 2m, could not read 440 reliably. I needed to replace my old 2 Meter 1/4 wave vertical antenna for the 146 mHz. Let say antenna/ load voltage is Vout = Vr + Vx, where Vr is resistive voltage and Vx is imaginary voltage. The Super J Pole. By John Portune W6NBC. Install 70cm stubs on the 2m antenna to create a good UHF radiation pattern. Ferrite bead balun installed. Remember that an antenna is also your first filter/preselector! After several years of contesting the 20m band appears one of our most successful bands, with the 5/8 wave vertical antenna being a crucial part of this success. With this web site, we like to inform you as much as possible (with the knowledge we have) about antennas. A couple of HF Bugcatchers. PSU for Amateur Radio from Computer. Having recently expanded my amateur radio collection to include 6-meters, I found myself needing something more than the wire dipole antenna I originally installed. Hams are (were) always trying new "stuff" it is more old school home brew ham rather than new buy it out of the box. First, the radiator is made from antenna wire, not the 450-ohm ladder line, as in the 2m J-pole. This one was also waiting for a PVC cover so it could be mounted on a pole. Many RASON members truly enjoyed last month's collinear antenna. The Super J-Pole Antenna(Collinear Design) Below is a Javascript for calculating the lengths of tubing to be used for the construction of a Super J-Pole. All information, images, and documents on this website are the sole property of MFJ Enterprises, Inc. The design would theoretically provide an impressive 9db gain (a claim that has generated some debate online) over the discone antenna I was using at the time. I have a single 2 meter copper J-pole that works great at a remote site. The homebrew J-Pole I was using would be okay, but it was limited to the 2 meter band and some of the repeaters in the area are in the 70 centemeter band. A J-pole is a balanced antenna, but a balun is not really necessary. The solder joints and stub matching point can be a bit of. The antenna I constructed was made of 1/2" tubing. So I am very close to the ~55-56″ of radiator length I will need. So being one who likes to build antennas, here is what I came up with. 7 dBi gain and 18° Vertical Beamwidth. I set to work to scale the antenna from its original size up to a length that would work for at least part of the 6 meter band. 2 meter long alu/copper pipe/tube of +/- 2028mm (square or round). PCS Electronics. 87 - Capacity Tuned Folded Loop Antenna for 20m. A 'J'-pole is a vertical 1/2 wave antenna fed by means of a sort of odd shaped 1/4 wave section. The measurements below are for building a simple Dipole Antenna. •Many types of antenna can be mounted in the attic IF you don’t have Radiant Barrier (Tech Shield). However shorter verticals (e. Rick Morgan. The first one of MFJ-1724B Magnet Mount Mobile antenna burned-out the capacitor in the. ost commercial 2-meter repeater antennas with gain fall into two categories:. End-Fed Half-Wave Antenna & Tuner - by VK2ZAY An End Fed Half Wave Antenna, by the late G3YCC end fed vertical j-pole and horizontal zepp - A reference of End Fed Myths - by W8JI (he'll dispel any believe that an antenna might work ;-) "EFHW" - the end-fed half wave antenna - by WA5BDU. dx-antennas. Yesterday morning around 8:00 local time, I heard during my breakfast signals from the beacon I0JX/B on 6 meters. If you have any questions about this project, contact [email protected] For 20 meters this would be just under 20 feet. Without Radials. How to build a 2 meter J-Pole T-cars virtual Elmer (swr adjustable clamps) 2 Meter J Pole Beam Jagi Tri-County Amateur Radio Club. 9” 5/8ʎon 2 meters is 50” and impedance matching is provided by a low inductance coil The above combination provides a base-loaded vertical antenna that works on 6 meters. In the middle of the night I realized everyone was using horizontally polarized antennas and mine was vertical! Now I see a J Pole might not be the best antenna for horizontal polarization on that band. 6 dB over the half-wave regular J-Pole. Six Meter Rigid Dipole 6 METER Half-Wave Dipole Antenna …. Super J-Pole Aaron Schmitz KB0YKI. Contact one of your local Diamond ® Dealers for current price & availability. This antenna is unique in that it is enclosed entirely in 3/4" PVC which makes the design a little more complicated. Most of my meters are now clearly labeled with the bands on which they will provide useful indications. W5DXP's No-Tuner, All-HF-Band, Horizontal, Center-Fed Antenna 6 Meter Antennas Six Meter Antenna Potpurri By Brian D. Most are standard VHF j-pole that resonates at UHF (all antennas do that). Let's Build One! The NVIS antenna described is based on the proven information from the military AS-2259/GR antenna. It rolls up and fits into the bag with no problem. Today I borrowed a swr meter to see what the swr is of my homemade 2 meters J-pole antenna made of 300 Ohm ribbon cable. About SWR; My OSJ 146/440 J-Pole went through 3 hurricanes in 6 weeks, with gusts speeds, on occasion, as high as 153 MPH. A 'J'-pole is a vertical 1/2 wave antenna fed by means of a sort of odd shaped 1/4 wave section. A couple of HF Bugcatchers. around the PVC just below the lower element, NOT underneath the antenna on the mast. The Image below […]. I made one for 4m (70MHz) which is 3 metres long! The quarter wave matching section can be made horizontal, with the half wave radiator section vertical, 90° to it if space is an issue. I had experimented with. In the first set of plans, the feed point is approximately 20% up from the shorted end of the matching stub. The photo to the right is an example of how the antenna may be supported with minimal holes or damage to the wall. The "boundaries" can be clearly seen. It was designed with 4nec2 NEC based antenna modeler and optimizer for 145/220/440MHz bands. The above radiation plots were produced using MMANA Antenna Analyser software by JE3HHT, Makoto (Mako) Mori. An antenna tuner is required for this antenna to properly function. The dimensions shown in Figure 2 produce a radiation pattern with low sidelobes and backlobes over the entire 2 meter band. I used a dual band hand held radio as a signal source and a Kenwood VHF/UHF power and SWR meter as a tuning indicator. J Pole Antenna Design Calculator by K4ABT I'll make a J Pole antenna for 20 meters. Earlier this year the 6 meter J-pole to which that beacon was connected seemed to have failed, exhibiting a high VSWR (around 5:1) and signals were down by 1-2. From the J-Pole formulas we derive the lengths of each wire pair, spacing of. use 6 foot side mount Top of antenna may requÑe: ulated supp ott at high (wind, ice) elevationy 1/2 INCH COPPER A 6 Meter J-Pole Antenna Author: K4ABT. 2 Meter Twin Lead J-pole Antenna. The antenna I constructed was made of 1/2" tubing. This page describes a simple to build, high gain, omni-directional direct-connect antenna for MURS and 2-meters. But what's a J BEAM? It's a vertical directional antenna made of 1/2 inch copper pipe and wood or PVC. I wound this on to the fishing pole which. Yesterday morning around 8:00 local time, I heard during my breakfast signals from the beacon I0JX/B on 6 meters. Portune, W6NBC here made from a threaded table lamp tube, the lower part of the whip becomes the cen -. This makes the 2 Meter Slim Jim antenna a great solution for repeater sites, data and packet stations, APRS, and even every day. It was so much fun to build and it works so well that I thought of sharing the details of my project here. AN ALL-COPPER 2-M J-POLE Rigid copper tubing, fittings and as-sorted hardware can be used to make a really rugged J-pole antenna for 2 m. I set to work to scale the antenna from its original size up to a length that would work for at least part of the 6 meter band. The original design was intended as a portable antenna but the twin-lead J-Pole on any frequency above 50 MHz lends itself well to mounted vertical use, it just needs a housing to keep it in the. A 40 meter magnetic loop. Only at eHam. 220 MHz not only has repeaters but has become a. This form of antenna originated as a practical solution to feeding a wire antenna trailing behind a dirigible. This is a good rainy day antenna project for those of you who would like to home brew a nifty low profile 2-meter antenna. SWR on two meters will be high. Bazooka Antenna Design — from WE6W Beverage— a short beverage design by K3KY Broomstick Special: — compact, easy-to-build. It uses a standard J-pole antenna as the driven element and center support, with two parasitic elements-----a reflector and a director, to provide directivity and. Enter the X50A. One 6 - meter "Jungle Antenna" ground plane cut for 51. This one was also waiting for a PVC cover so it could be mounted on a pole. Way to go Chris! Posted by K4GTM at. Stripping off the 10. VHF Magnetic loop By ON1DHT; 2m Quagi By W5UN. Building the J-Pole antenna (PVC covered) KA1FSB. The silver I'm refering to is what a/c tech's use to solder. The impedance of this antenna is around 300 Ω, so you may want to use a transformer or a λ/4 long piece of 120 Ω coaxial cable to match this impedance to 50 Ω. 4 GHz 10 el. Got it in the air and on the air in time for a local 6 meter net. Simplified 2 Meter J-Pole (pdf) Michael Martens KB9VBR. The W4MMQ Legacy Balanced Antenna Tuner Shack External Speaker Radio Shack Headphones MFJ 24 Hour LCD Clock Arrow Dual Band J-Pole Arrow 2-Meter Corner. I've heard Tim (HLR) and others talking about it, so this morning just before work I fired up the Flex 1500 (5 watts outpoot) and using a 220 Ft long flat top at 90 Ft, I was able to work 2 Italian stations, the Ukraine, and Germany through modest pileups. For years there have been many home brew projects to construct similar antennas but no high quality versions have been commercially available until now. This how to will show you how to build a 2 meter slim jim antenna from ordinary insulated copper wire commonly used for carrying AC (alternate current) electricity in your. >> > Which antenna is better: 5/8 wavelength vertical or a J pole? >> >> Better for what? For example, a 5/8 whip would usually be better than a J > >Owen, I think the popularity of VHF mobile 5/8 antenna lies in it has >more gain than a 1/4 wl antenna and is easier to match to 50 ohms than >a. Wire versions are usually the answer. Wire length in Collinear J-Pole Phasing Coil. Go to the W3FF Buddipole / Buddistick site for the original homebrew construction details. 2 meter long alu/copper pipe/tube of +/- 2028mm (square or round). Most home made versions will probably work worse than a simple 1/4 wave ground plane made from scrap wire due to mistakes made in dimensions or matching the J pole. 88 - Indoor Loop Antenna for 80m to 30m. net homebrew topics A selection of various homebrew items. There are three possible conditions, they are:. Homebrew Coaxial Dipole for VHF or UHF Here's a base station antenna you can easily build for 146, 220 or 440 MHz. I needed to replace my old 2 Meter 1/4 wave vertical antenna for the 146 mHz. This makes the 2 Meter Slim Jim antenna a great solution for repeater sites, data and packet stations, APRS, and even every day. One way to do that is to replace that little rubber duck antenna with the ever-popular Twinlead J-Pole. 6 Meter J-Pole Antenna. However, it took about 80 inches of wire to make the 22 turn coil. Homebrew or restore one. Quarter Wave Dual Band VHF/UHF Ham Radio Antenna. In the future perhaps. The primary problem is that PVC tubing has a significant velocity factor which causes RF to slow down. Install 70cm stubs on the 2m antenna to create a good UHF radiation pattern. I home built a j pole antenna and with careful tuning I adjusted it to just a bit over 3 db gain as compared with a 1/4 wave ground plane. Authentic N9TAX VHF Slim Jim J-Pole 2 Meter Antenna roll up jpole!! Use with. We thought some of you may be interested in it. 2 meter corner reflector I experimented with. Kinsner, VE4WK J-POLE ANTENNA FOR 2m 3 of 3 1 2 3 4 5 6 7 8 E D C B A E D C B A 1 2 3 4 5 6 7 8 5 June 1992 J-POLE PARTS LIST PROCEDURE P2 M1. nl down and made it a mirror site linking to this page. This antenna has been fully tested to 150 MPH winds using Lowe's 23990 and 3/4 inch pvc pipe. This is called the j integrated match (jim) the antenna itself is very slim hence the name Slim Jim. Homebrew Ham Projects. Steve, Just to let you know HOW good 10 meters is. It is totally UV protected and should last easily 10 years on a repeater mountain top. All information, images, and documents on this website are the sole property of MFJ Enterprises, Inc. Remember that an antenna is also your first filter/preselector! After several years of contesting the 20m band appears one of our most successful bands, with the 5/8 wave vertical antenna being a crucial part of this success. 5 inches and the 1/4 wavelength stub section (Section B) is equal to. The design uses a matching system like a j-pole antenna. For years there have been many home brew projects to construct similar antennas but no high quality versions have been commercially available until now. I could hear the moderator and lots of attendees but I could not join the net. Antenna gain is measured in either dBi or dBd. J-Pole antennas are highly effective, affordable antennas for the VHF and UHF frequency spectrum. It works like any other 1/2 wave length antenna for the most part. Your going to like this super J-pole project, This home made j-pole is easy to build and sturdy, While looking for an jpole antenna project to build I remembered seeing a Marine antenna called the Super J-Pole in the 1988 ARRL Antenna Handbook, which claimed a 6 db gain over a quarter wave ground plane. This is the hairpin match I made for a 6 meter yagi. 3:1 at resonance. Let say antenna/ load voltage is Vout = Vr + Vx, where Vr is resistive voltage and Vx is imaginary voltage. After working three years with a homemade DL6WU type 6-element-antenna, I was intended to build something new as the old antenna decided to fall apart. Place a 1:1 Balun on the Antenna end of the Feedline. MFJ-1622, MFJ-1625 Window/Balcony Antenna 80-6 Meters : MP Antennas:. If 9 dB gain is still not enough for you then increase the number of coax elements from eight to sixteen. 8 out of 5 stars 3. build antenna project for 2 meters. On most of the J Pole designs out there, a choke should be used as close to the feedpoint of the antenna as possible to help prevent rf on the feedline and creating difficulty with SWR readings. Reinstall, then remove the 6 1/4" element. This antenna is unique in that it is enclosed entirely in 3/4" PVC which makes the design a little more complicated. Get Rockwell’s 6 meter beam construction details from here and his BALUN information from here. The idea of s circularly-polarized omnidirectional antenna is a bit hard for some folks to wrap their heads around, but they are quite common: Antennas used on GPS receivers are circularly-polarized and have a more-or-less hemispherical response so that they "see" the sky, but not as much of the ground. The inductor on the CB antenna makes the antenna electrically longer than its actual radiator length. Without Radials. ost commercial 2-meter repeater antennas with gain fall into two categories:. The Super J-Pole Antenna(Collinear Design) Below is a Javascript for calculating the lengths of tubing to be used for the construction of a Super J-Pole. by Al Peter, AC8GY. stub-j-pole-project-completed-many-times, Jeff had the same idea as we did. Our flagship model, The Two Meter J-Pole Antenna comes in two different configurations, either as a one piece antenna for base station use, or as a two piece breakaway model great for portable operations. As a bonus, the antenna will perform acceptably on the 20, 15, 12, and 6 meter bands if an antenna tuner is used. This simple antenna lends itself well to emergency use or as a portable antenna for hotel room operations while traveling. Obviously, that particular meter, though fine for HF and okay on 2m, could not read 440 reliably. Enter the desired operating frequency in megahertz to get a good starting length for a dipole in both feet and 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. Now you've probably heard of a beam antenna, and maybe you've heard of a J-Pole. Amateur Radio Homebrew Projects on the Net This page is dedicated to Amateur Radio Homebrew. Slim Jim (J Integrated Match J-Pole) is probably the most easiest and powerful 2 meter antenna to build provided you have the exact measurement and material to build it. Only at eHam. This new antenna has a 1:1 toroid balun and a SO. You need to go read the articles here before you decide that the J-pole is the antenna for you. · 6 meter Amateur Radio Antenna - KB9VBR J-Pole Antennas - Great for FM communications, the 6 meter J-Pole covers the 50-54MHz six meter amateur radio band efficiently and with a low noise floor. Geometriy is not that critical. 102" whip for rooftop 10 Meter vertical. The Image below […].