40m Doublet Antenna

Google “EFHW” along with their call signs and you will get there. 134 feet high at top. My Interests Ham Radio. Using a 2x6 antenna switch to share antennas betwen 2 radios (Flex 6500 and 6700) or to let the 2 SCU's in my 6700 do SO2R. Unfortunately, this antenna is widely misunderstood. This antenna worked very well for 40M-10M. 83’ 3/8 lambda 40 METERS = 65. Currently I have a coax fed trapped 75/40M dipole up between two trees. G5RV - 102 ft. These antennas REQUIRE the use of an Antenna Matchbox on all bands. Recently I've been fielding service problems from people using 88-foot long dipoles. #2 - The doublet with parallel feedline. 75 lambda Folded dipole lengths shorter. This is a very valuable tool, particularly on the 160 meter band. However, in several auto ATU manuals one antenna … Continue reading →. I also found a design for a linear loaded vertical antenna for 40m and 80m. That way with winds etc the trees can sway and not destroy the antenna. 229 - Wire Log Periodic Antenna G=12dB for 15m, 20m. I use a 44' doublet and a Elecraft QRP tuner, which covers 40m-6m up to 20W and is about the size of a paperback book. 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. You will need to suspend it but it can also be used as a long wire with your tuner by shorting out the feed end if you only have a single tree to support the end. Loop mainly used for RX on 160, 80 and 40m. If only 80m and 40m were considered, the idea is to make an antenna half way between 20m (¼ of 80m) and 10m (¼ of 40) ie. Dualband Full-wave Loop Antenna for 80m-40m 34 58. I've never bought (or built) an antenna before and was looking for some general advice on what to buy (or build). The open line runs from the shed out to the back yard. Calculate a Dipole. 76 - Half Rhombic Unidirectional Vertical for 20m to 6m. The garden, which measured only 20m by 14m, was too small to accommodate a G5RV; the location of the shack on the opposite side of the house from the garden made an open-wire-fed doublet impractical; and it was not possible to provide. It is just a dipole cut for the lowest frequency desired and then fed with ladder line to a tuner. 235 - Phased Delta Loop Array for 20m. The inverted Vee antenna will be shorter by 2 - 5% depending on the angle from horizontal. On a whim I "auto-tuned" the doublet to 30M. Any of these antenna systems are excellent candidates for "king-of-night-time DX. A dipole is very simple to build. ALL BAND DOUBLET DIAGRAM Shown using 450 ohm Ladder line Shown with standard TV type 300 ohm ribbon line Details and construction The all band doublet antenna is nothing more than a 1/2 wave dipole cut for your lowest operating frequency and fed with twinlead, ladder line, open wire, etc to a tuner that will accept a balanced line connection. Let’s examine the antenna pattern of a 40m dipole at various heights above average ground by first viewing the energy broadside to the antenna. Transceiver Icom IC-775DSP Antennas: Carolina Windom cw160s, 5mhz Doublet, Topband Inverted L, Homebrew,20m loop with 1/4 wave matching stub. Finally, the key to NVIS is the antenna height, like Pelican 1984 says: Optimum height for NVIS antennas is 0. The DXE DV. Like all inverted vees, it requires a single center support, which is often times a tower which is topped with a Yagi or quad for the upper bands. 164 - Horizontal Loop Antennas. These tuners can typically tune an antenna as short as 8 ft from 3. 20 - Multiband Tuned Doublet Antenna. It's a dipole fed off center with a 4:1 current balun at the offset feedpoint. My Top Five Backyard Multi-Band Wire HF Antennas L. The all band doublet antenna is nothing more than a 1/2 wave dipole cut for your lowest operating frequency and fed with twinlead, ladder line, open wire, etc to a tuner that will accept a balanced line connection. 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. These branches would make a suitable support for an 80-10 Meter half-wave doublet or flat-top dipole. A folded dipole has a feed-point impedance of approximately 300-ohms rather than 70 or 72 ohms. Note: The words aerial and antenna are used interchangeably by the layman, although accurately speaking, the top or elevated portion of the antenna is the aerial, and that portion which completes the electrical connection between the elevated aerial portion and the instruments is the lead-in. In fact, a half-wave dipole will often outperform many compromise commercial multiband antennas. 232 - Doublet Antenna for 160m. Multi-band with antenna tuner. This is a very valuable tool, particularly on the 160 meter band. Stealth antennas for the loft Fig 4. Trimming a dipole antenna refers to the adjustment of antenna length to operating frequency. The garden here at PZT Towers is 50ftx20ft so a full-length flat-top dipole/doublet to get me onto 7MHz was out of the question…. Antenna return loss is indirectly proportional to SWR and is the method used to determine SWR of higher frequencies that make "antenna analyzers" and SWR meters impractical. When someone hears it on the air and then buys one for their station, that antenna has to be something special. In fact, a half-wave dipole will often outperform many compromise commercial multiband antennas. , and are perfect for RVs, vacations, Field Day, or as your go-kit antenna. If I use antenna 2 in 40m, when I get back to 40m coming from any other band, the antenna 2 will be remembered. G5RV – 102 ft. 89: ICOM IC2730A 2m/70cm Mobile $244. Used external Trimble $20 eBay 10MHz oscillator calibrated to WWV. 160 - Marconi Antenna for 136 kHz. Add to Wishlist | Add to Compare; Diamond W-735. A Hawaii-based Amateur Radio Antenna Blog focusing on the theory, design, and use of homemade antennas. Then the idea was for it to be a half wave dipole for 40m. Antennas for Autotuners, KG4JJH 3 of 5 Antenna 3: 102-foot doublet at 35 feet elevation fed with Wireman 552, ladder line (450Ω, 0. 227 - Double Extended Zepp Antenna Gain=7dB for 15m. Wire antennas are a great simple way to work 40M and 80M rather than a noisy vertical antenna that requires horizontal radials. My first thought was to remove the balun from my 40m dipole, feed with ladder line from an external auto-ATU and treat as a doublet. 12 wavelengths. What attracted me to try a Delta the most was the Delta's reputation for working well close to the ground. 89: ICOM IC2730A 2m/70cm Mobile $244. An external antenna tuner is required to provide a low VSWR. Multiband Dipole Antenna 33 56. The 88’ variety works on 20-40-80. Let's examine the antenna pattern of a 40m dipole at various heights above average ground by first viewing the energy broadside to the antenna. Contact one of your local Diamond ® Dealers for current price & availability. It's easy to deploy, tunes easily, and covers all the bands of interest. I was asked several times (even in CW over the air) what kind of antenna I was using and this post shall give an answer. But I've worked with lots of new hams, and a dipole is cheap, quick, and easy to construct. K1POO 4 Band Off Centre Fed Dipole (40-20-15-10m ) 40m 20m 15m 10m The freeware antenna modelling program MMANA-GAL was used to study the K1POO Antenna. These tuners can typically tune an antenna as short as 8 ft from 3. Tap placement is critical on the 80m tapped-coil network (a two inductor L network!). DELTA LOOP 40m loop antenna 40-6M £54 99 DELTA LOOP 80M 80-6M BANDS £71 99 DELTA LOOP quad antenna price for a 20m loop £49 99 DIPOLE 20m dipole 1kw 1-1 balun all other bands available £45 00 DIPOLE 40-6m OFF CENTRE FED DIPOLE WINDOM STYLE £55 99 DIPOLE 80-6m OFF CENTRE FED DIPOLE WINDOM STYLE £65 99 DOUBLET ANTENNA £39 99 END FED 1kw ssb end fed antenna (80) 40-6m £43 99 END FED 3. Used external Trimble $20 eBay 10MHz oscillator calibrated to WWV. 238 - Two-Band Quad Loop Antenna 80m, 40m. 20/15M Moxon up 55’ (also Good on 17, 12 & 10M) K9AY Loops for 160/80M Receive. Later they were fed with two wires (which I generically call openwire) and called a Double-Zepp Aerial (or Antenna) because they could be viewed as being two single-wire Zeppelin antennas, fed with a common balanced feedline. These branches would make a suitable support for an 80-10 Meter half-wave doublet or flat-top dipole. Multiband Z Antenna 33 55. The difference between using Traps and just having a 40m Doublet, is that with traps on each band it's a resonant half-wave dipole, with the classic waveform. The doublet has a long history and its longevity is perhaps down to two factors: ease of construction and its being an effective multi-band radiator. I am sure going to build this 20m vertical dipole. A 40m Doublet will have multiple lobes on the higher bands, with big peaks and nulls in different directions. The random length all band doublet represents some clear advantages in cost and operational flexibility within the limitations of the average Australian suburban block. Half way there is another 80 meter coax trap. Rotating Dipole 40m-6m. Ladder line lengths of 30-31 and 64-65 feet imply five tunable bands. 5' per side. I tuned the doublet to 20m, set my radio on 50W and tried to make contact. The 80 Meter Doublet Antenna — 88 Ft/25Ft 300 Ohm Twin-lead. If we had chosen a 67' doublet, the antenna would be wavelengths on 40 meters, 1 wavelength on 20 meters, and 2 wavelengths on 10 meters. Any reuse or redistribution of the contents of this website are strictly forbidden without authorization from MFJ Enterprises, Inc. An antenna construction workshop conducted at Marshall N1FN's QTH on Sunday, 8/2/98 Mission: Replace an old co-ax fed 40M dipole with a new one, fed with 300 Ohm ladder line and in doing so provide a "workshop" for the necessary techniques, and document the process for "posterity. 236 - Dual Band V-dipole for 80m, 40m. But I’ve worked with lots of new hams, and a dipole is cheap, quick, and easy to construct. Thanks to all 73 Dick WB4BIN - Fun sprint! 20m was in pretty good shape tonight, and my dipole was working well there. You may be better off with another antenna for 20m-10m, which is what I do. 216 sat 2 meter 16el twist. The all band doublet antenna is nothing more than a 1/2 wave dipole cut for your lowest operating frequency and fed with twinlead, ladder line, open wire, etc to a tuner that will accept a balanced line connection. skinny rig was ATS4A, T1 tuner, 3Ah Bioenno battery, Whiterook cootie, light headphones1. - 160/80/40 meter band - trapped dipole - 2007. Currently I have a coax fed trapped 75/40M dipole up between two trees. Double Bazooka Coaxial Dipole Antenna Info There is a lot of controversy surrounding the Double Bazooka Coaxial Dipole. multi-band antenna. All-Bands Dipole Antenna 32 54. Salve a tutti, in questi giorni ho letto molte discussioni, fatte nel tempo, in merito alle varie antenne verticali e quindi la domanda che pongo agli esperti non è relativa a quale sia la migliore antenna, ma se vale la pena, in termini di rendimento teorico/ pratico, sostituire la mia attuale canna da pesca con una Hy-gayn tipo av640/680 o con antenna tipo Gap eagle o titan. IAC Antennas featured on Ham Nation! IAC Antennas worked with Bob Heil, K9EID, to help him set up an IAC Phased Array at his new QTH. Resources listed under dipole category belongs to Antennas main collection, and get reviewed and rated by amateur radio operators. Since it is a full wave antenna, you get twice the wire of a dipole into and onto the air. 80m doublets appear to be the largest commonly used. Dipole Antenna Calculator. A big difference, obviously. A whip is supplied that connects to the top of the coil. Transceiver Icom IC-775DSP Antennas: Carolina Windom cw160s, 5mhz Doublet, Topband Inverted L, Homebrew,20m loop with 1/4 wave matching stub. 160m Inverted Delta Loop. PackTennas are light weight, compact, portable HF antenna systems ideal for operating on the trail, at the campsite, on Field Day, SOTA activation, air travel, or HOA restricted locations. Contact one of your local Diamond ® Dealers for current price & availability. Most commercially-made G5RV antennas are lossy because they are fed with coax. Multiband Tuned Doublet Antenna. All-Bands Dipole Antenna 32 54. The 40m QCX kit will be my first HF station. The Half Square antenna is a wire antenna with two vertical radiators fed in phase. A 1:1 Current Balun (aka: Choke). 164 - Horizontal Loop Antennas. After moving to a valley in western Montana, I wanted to position an antenna on a high, wooded ridge to the east of the house. If you want to use a dipole for a band of frequencies, you cut it to the center frequency on that band, and hope it has a low enough SWR at each end of the band. Regional Communications Needs • 400 mile radius NVIS 40M antenna. Battery: a 4 Amp LiPo which seemed weak by end of Sprint. Like all inverted vees, it requires a single center support, which is often times a tower which is topped with a Yagi or quad for the upper bands. The Western HF-10 multiband dipole was born out of Fred Western M0BZI's attempts at working 80m from a small garden. Post #1551. The big difference is, the Cobra's unique close-spaced multi-wire element also introduces two added resonant responses below the antenna's fundamental operating frequency. Forgot to add it worked on 10m-40m at full 100 watts. On the bands above 20m it will work, but the performance may be down on what you could expect from a half-wave dipole cut for each particular band. This is an End-Fed Half-Wave (EFHW*) antenna for 40/20/15 and 10m bands. antenna, we can achieve an SWR of less than 2:1 on all frequencies on all HF bands with the exception of the lowest part of 80m. Learn More. height AGL. The DXE DV. 22 - Wideband Dipole Antenna. G8JNJ 'Fat-Max ® ' HF Antenna - 6m to 40m - the poor man's Steppir. 162 - Stub-Directed V Antenna for 80m. EFHW-4010-1K Multi-Band End Fed Half Wave Antenna. R Radio Telescope (Argentine Institute of Radio Astronomy) with 30 Mts dish antenna, will be Radio Direction Finder DF2020T DF2020T Radio Direction Finder kit requires minimum assembly for 10~15 Minutes The Stealth DDF2020T/. Just over 300 people responded. The dipole antenna is said by many to be the perfect antenna for a specific frequency. For the most part, this is true. Since I was not concerned about the pattern above 40m and because I was hanging it as an inverted V I decided that the “Dipole Doublet” would be my antenna. 63 - Wire-Beam Antenna for 80m. For now, to keep things simple, we'll assume that the ladderline and the tuner have negligible losses. Rig was KX3 @ 5 watts. He says it is also possible to operate on both 80m (3. Use 75 or 50 ohm cable to feed the centre of the dipole. It will be feed with 50 ohm RG-8X having a 12 turn, 12 inch RF Choke and uses a K1FZ KB-5 toroid matching transformer. 165 - Ribbon J-Pole for 2m. A Hawaii-based Amateur Radio Antenna Blog focusing on the theory, design, and use of homemade antennas. 73 - Curtain Zepp Antenna for 160m, 80m, 40m. The doublet has a long history and its longevity is perhaps down to two factors: ease of construction and its being an effective multi-band radiator. 128 – 5-Element Log-Periodic Vertical Antenna for 80m, 40m, 20m. If you've ever priced an analyzer, and have a need for one, that makes measurements above 450 MHz, you may be pleased to learn of this method. My initial aim was actually for a 60 meter dipole antenna. 166 - Dual Band Ribbon J-Pole for 2m, 70cm. Start with cutting the radiating and reflecting elements. I was glad to find that it came with a SIP socket strip to use for the crystal socket. Also have a 4 element yagi on 10m on the roof @ 30'. 40m Coaxial Dipole Antenna aka Double Bazooka. One antenna uses all coax the other uses coax and twin lead for the antenna. Again, the tuner easily tuned the antenna on all the bands tested and QSOs were successfully made on 20m and 40m despite poor band conditions. A big difference, obviously. The Doublet Antenna is a dipole antenna with a resonant symmetric feeder line. It is an antenna that is actually 1. Install the antenna as high as you can go run the ladder line to tuner, enjoy. 88 ft and 44 ft are popular lengths. Each stub-loop antenna 31 of the exemplary antenna doublet system 30 is similarly oriented as its neighboring stub-loop antenna 31 to provide a uniform arraying effect. 160m Elevated Fibreglass Vertical Antenna -G3SZU iss 1. 231 - Sloping Delta Loop Antenna for 40m. 20 - Multiband Tuned Doublet Antenna. 61 - Tri-band Delta Loop Antenna for 80m - 40m - 30m. It is just a dipole cut for the lowest frequency desired and then fed with ladder line to a tuner. I say fantastic only because when you compare the height requirements and maintenance requirements, the phased array has tremendous bang for the buck. The Hertzian dipole or elementary doublet refers to a theoretical construction, rather than a physical antenna design: It is an idealized tiny segment of conductor carrying a RF current with constant amplitude and direction along its entire (short) length; a real antenna can be modeled as the combination of many Hertzian dipoles laid end-to-end. The doublet antenna is a form of dipole that uses a balanced feeder, often open wire feeder and an antenna tuning unit. Loop Antenna for 10m 35 59. My Interests Ham Radio. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. Gain is pretty decent around 6dBi at useful elevations (for NVIS contacts), it is an improvement over my previous dipole antenna, the 66 foot doublet. 8 band vertical. 80m Cobra Doublet. The FT-950 memorizes the antenna input connector used with each band. One of my 2008 antenna projects was a square spiral loop antenna for the 80 meter band. Configuring and Tuning the Buddipole ! TheBuddipoleisdesignedasaninductively 'loadedoff'center'fed!(asymmetric)!dipole. 160 - Marconi Antenna for 136 kHz. I read a nice article by A. 40m V Dipole - It's up and awesome! Well, it sure has taken me a while, but I decided that I needed to remove my doublet. Start with cutting the radiating and reflecting elements. My original antenna was a 40m dipole made from some #14 THHN wire, hanging from some trees in my yard. 05 Is trying to build a trapped dipole for 160/80/40 meter bands. The Endisolators are simply attached with narrow Cable Ties at the bent ends. Again, the tuner easily tuned the antenna on all the bands tested and QSOs were successfully made on 20m and 40m despite poor band conditions. But I’ve worked with lots of new hams, and a dipole is cheap, quick, and easy to construct. date 10m 12m 15m 17m 20m 30m 40m 80m 160m chall cw digi honor mix ssb 25. Even zip cord such as what is used for lamp cords will perform quite well. If it was me I would go this route. By Guy Atkins. On 40m, we are feeding it with 3/4 wavelength of ladder-line. 5 VDC to provide power to the microcomputer located within the housing. There are no mechanical or soldered connections between the feed line and antenna since each side is one continuous piece of wire. The reference antenna length was chosen to resonate at the ½ wavelength height. They require about 1 ampere at 13. About 15ft for 40m, and 31ft for 80m. I have two such antennas: my home antenna is a 102' doublet fed with 300 ohm window line, and my portable antenna is an 88' doublet fed with 450 ohm window line. 25 long center fed dou- blet as shown in Figure 1. HF Antenna Next Steps In order to improve my HF antenna I plan to double its length so that I can use it more successfully on the 40m band. 1 KiB: 2016-Jul-20 22:30: 61-Tri-band. Buxton, W8NX in QST July 1992 Issue. The NorCal Doublet Antenna came about due to my desire for a simple antenna that could be erected very fast, only needed one center support, and did not take up much storage room. The 160 - 10m doublet experiment will last for three months (February - April 2018), and after this period the performance and building quality will be evaluated. If you want to use a dipole for a band of frequencies, you cut it to the center frequency on that band, and hope it has a low enough SWR at each end of the band. - 160/80/40 meter band - trapped dipole - 2007. Okay, as I noted before, my first antenna wasn’t a dipole. Folded dipole antenna: As the name states, this type of antenna has one of the halves folded back onto itself. G5RV Antenna. Usable NVIS service occurs from 6 to 24 feet above ground with energy directed. It can be fed with ladder line from the center insulator to tuner or it can use an impedance. The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole with a radiating structure supporting a line current so energized that the current has only one node at each end. is connected to my shack's QRP 40M extended double zepp (176 ft overall, fed with 300 ohm twinlead). The 10m and 15m bands were not checked for activity. The N6BT DXU-32 … I have had two occasions where I was able to test my fantastic 40M phased vertical array against other antennas. The 80 Meter Doublet Antenna — 88 Ft/25Ft 300 Ohm Twin-lead. Homebrew 40/80 Trap Dipole Design This Antenna design was one that I used about 4 years ago, it worked exceptionally well on 80m and 40m. In either case, I’m very happy with the antenna. (See Shack Talk, Your First Dipole Antenna for information on calculating approximate dipole lengths. Even though it is a "compromise" antenna, it has good overall performance on most hf ham bands when used with an external tuner, and allows coax as an entry feedline to the radio equipment eliminating the need and hassle of ladder line or twinlead. 80m overall length - 134' or 67' per side. As open wire feeder is able to operate with levels of standing waves and effectively becomes part of the antenna, it is able to operate over a wide band of frequencies. This antenna worked very well for 40M-10M. 9 Qs on 40, 6 Qs on 80. HF Antenna Next Steps In order to improve my HF antenna I plan to double its length so that I can use it more successfully on the 40m band. The doublet is positioned such that the wires exist in the Y-plane and radiation is broadside towards the X-axis direction. So I'm no longer using this attic antenna for 80m but it's working great for 40m and above. Perhaps too many new hams embarking on their first HF adventures think only of resonant dipoles fed with coaxial cable and plugged directly into the transceiver's output connector. Table 2 provides the most convenient lengths and the bands included. The red squares indicate 50Ω SWR less than or equal to 10:1 for ladder line lengths of 1 to 125 feet. 89: ICOM IC2730A 2m/70cm Mobile $244. All information, images, and documents on this website are the sole property of Hygain Any reuse or redistribution of the contents of this website are strictly forbidden without authorization from Hygain. The dipole antenna is said by many to be the perfect antenna for a specific frequency. Baluns for Multiband Antennas fed with Open Wire or Ladder line Posted by Bob, KZ5R on 20th Nov 2014 At least once a week we receive a request a for high ratio balun (6:1, 9:1, 12:1) to manage the transition from high impedance ladder line / open wire feedline to coax. It is fed with 30 metres of Westflex 103, and there is a 1 to 1 ballun at the feed point to the aerial. COM web site. Built to the usual TET-EMTRON quality, the.   It is worth testing out for a bit longer though. Electrically it is very different to a conventional dipole; it incorporates a balun and is almost like having two quarter-wave dipoles connected side by side. It'll also be the first non-HT that I'll own. There for if you can have only one HF antenna the random length all band doublet would be a pretty good choice. If only 80m and 40m were considered, the idea is to make an antenna half way between 20m (¼ of 80m) and 10m (¼ of 40) ie. Experimental measurements and calculations show that with this number, the loss resistance decreases the antenna efficiency. The random length all band doublet represents some clear advantages in cost and operational flexibility within the limitations of the average Australian suburban block. 40M and 80M were a bit noisy but not unusable. 1 - 40m dipole broadside gain patterns vs. The ULTIMAX-8040 broadband dual band double bazooka for 40 & 80 meters is a fantastic antenna using a newly designed “HY-Q” coax coils that gives outstanding broadband performance on both bands requiring only 103' feet of space. Tuner At The Antenna – The method favored by the military and marine antenna designers is to place an auto-tuner at the antenna as shown in Figure 17. I have previously made other trapped dipoles using the standard coax-trap design. There for if you can have only one HF antenna the random length all band doublet would be a pretty good choice. These are going to be the two halves of your dipole antenna. Like all inverted vees, it requires a single center support, which is often times a tower which is topped with a Yagi or quad for the upper bands. The NorCal Doublet Antenna came about due to my desire for a simple antenna that could be erected very fast, only needed one center support, and did not take up much storage room. , and are perfect for RVs, vacations, Field Day, or as your go-kit antenna. I say fantastic only because when you compare the height requirements and maintenance requirements, the phased array has tremendous bang for the buck. Dualband Full-wave Loop Antenna for 80m-40m 34 58. Bob is the host of the popular Ham Radio broadcast, Ham Nation as seen on Twit TV and has featured and demonstrated this phased array system on two separate episodes. HF Antenna: All Band Doublet Another thing that I did over the Dec/Jan holidays was finally get an HF antenna back on the air, hanging from the south outrigger on my combination TV / Ham tower. Currently I have a coax fed trapped 75/40M dipole up between two trees. Although twin lead, (a 300-ohm transmission line used on TV and FM antennas in the 50s to the 70s), is not available at most stores, you still find it around and it's a cheap and efficient way to make an efficient antenna. 27 - Reduced Size Dipole Antenna. The Hertzian dipole or elementary doublet refers to a theoretical construction, rather than a physical antenna design: It is an idealized tiny segment of conductor carrying a RF current with constant amplitude and direction along its entire (short) length; a real antenna can be modeled as the combination of many Hertzian dipoles laid end-to-end. Rig was KX3 @ 5 watts. Diamond ® Antennas are sold through authorized dealers. I was glad to find that it came with a SIP socket strip to use for the crystal socket. All readings were taken with a Array Solutions AIM-1470b Antenna Analyzer. All information, images, and documents on this website are the sole property of MFJ Enterprises, Inc. 21 - G5RV Antenna. Over the last few decades, the G5RV antenna has become one of the most popular and widely used "all around" multi-band antennas in the world. MFJ-2982 Feather Lite HF Vertical Wire Antennas are 31 ft. G3RWF Doublet –40m antenna wire only 18m apex & slopes to 15m – base line of dipole impedances. Individually pretuned matched traps for each band, 50 Ohm feed; coaxial cable not included. 2(a): You can see that when erected in a straight line the dipole is quite directional. 80m Cobra Doublet This aerial is called, to use a technical term, an 80m Linear-Loaded Doublet - known in the USA as a "Cobra" due to the snaking of the wires. Resources listed under dipole category belongs to Antennas main collection, and get reviewed and rated by amateur radio operators. 236 - Dual Band V-dipole for 80m, 40m. 40m Dipole on 15m. G-Whip antenna products. Usable NVIS service occurs from 6 to 24 feet above ground with energy directed. 40M Antenna Directions, Pattern and Gain. !The basic!elements!fromwhich!the. Basically, the Extended Double Zepp Antenna is a pair of 5/8 wave elements. A 40m Doublet will have multiple lobes on the higher bands, with big peaks and nulls in different directions. Using a tuner, they are usable to 30 MHz and come complete with the wire elements, ladder feedline, center T support, and end mount brackets. works well with my IC-756PRO. 80m overall length - 134' or 67' per side. This should give you basically the same basic antenna pattern on all bands, 10-40M. How to fit and fold an attic fan dipole? 80M, 40M, 20M, 10M. 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. I read a nice article by A. Dual-Band Sloper Antenna 39 de 45 ANTENNAS 63. They were asked to choose their ";favourite portable antenna" from: Ground-plane W3EDP Endfed Halfwave Single Band Dipole Random Length Endfed Doublet Linked Dipole Magnetic Loop Multiband Loaded Dipole Other The order the antennas were listed in was. The best antenna I have built was a 40m elevated ground plane. I also used many different full wave loops on 40m. But, you say, dipoles are only single-band. M0CVO HFC-3015V Vertical Short Antenna for 40m - 10m Recently I had a new mast fitted for my 2m and 70cm antenna's and in the process lost the centre support for my HF doublet and needed something to replace it that wasn't too intrusive. Stayed on 40M all sprint. Homebrew 40/80 Trap Dipole Design This Antenna design was one that I used about 4 years ago, it worked exceptionally well on 80m and 40m. 5 dB/D in conjunction with element 1B. It's just a different way of installing the quarter-wave vertical. 21 - G5RV Antenna 5-Element Log-Periodic Vertical Antenna for 80m, 40m, 20m. Tri-band Delta Loop Antenna for 80m - 40m - 30m 36 60. That W5GI antenna I mentioned is really easy to build with cheap stuff. 5' per side. There for if you can have only one HF antenna the random length all band doublet would be a pretty good choice. In addition, a doublet must always be used with an antenna tuning unit (ATU) due to the impedance mismatches. An automatic tuner should tune this antenna with no problem. , extreme low or high impedances) at the tuner end, on all bands. Antenna Height When Mounted On TM2 SuperPod Large Tripod. One vertical element (1/4-wave) is fed at the top where it is attached to a SO-239. 8:1, followed by the 40 m wires then the 80 m wires. That was a little over a week ago and I've had some time to play with this new antenna. 05 Is trying to build a trapped dipole for 160/80/40 meter bands. -V configuration. The antenna is constructed much like an ordinary Dipole antenna but with 5/8 Wavelength Elements matched with an added Impedance Matching Section of balanced feed line. 29 - Delta. ) When the dipole is properly trimmed for an operating. The MMANA-GAL model results shown that the resistance alternates between low and high values, and the reactance similarly changes between inductive and capacitive values as the antenna increases in terms of wavelength. 167 - Square Vertical Loop. The reason a G5RV has a cut to length ladder line is the line is used as a match device as the antenna is also match to use with a transmitter. Let’s examine the antenna pattern of a 40m dipole at various heights above average ground by first viewing the energy broadside to the antenna. The DXE DV. 5 m between 20 m trap and 40 m trap and 11 m between the 40 m trap and the end of the antenna. I plan to re-jig things a bit and try to go direct into a balanced line antenna tuner to avoid. Extended Double Zepp - Longer than a dipole. Antenna gain pattern shapes with respect to antenna height. Wire antennas are a great simple way to work 40M and 80M rather than a noisy vertical antenna that requires horizontal radials. The fact-checkers, whose work is more and more important for those who prefer facts over lies, police the line between fact and falsehood on a day-to-day basis, and do a great job. Today, my small contribution is to pass along a very good overview that reflects on one of Trump’s favorite overarching falsehoods. Namely: Trump describes an America in which everything was going down the tubes under  Obama, which is why we needed Trump to make America great again. And he claims that this project has come to fruition, with America setting records for prosperity under his leadership and guidance. “Obama bad; Trump good” is pretty much his analysis in all areas and measurement of U.S. activity, especially economically. Even if this were true, it would reflect poorly on Trump’s character, but it has the added problem of being false, a big lie made up of many small ones. Personally, I don’t assume that all economic measurements directly reflect the leadership of whoever occupies the Oval Office, nor am I smart enough to figure out what causes what in the economy. But the idea that presidents get the credit or the blame for the economy during their tenure is a political fact of life. Trump, in his adorable, immodest mendacity, not only claims credit for everything good that happens in the economy, but tells people, literally and specifically, that they have to vote for him even if they hate him, because without his guidance, their 401(k) accounts “will go down the tubes.” That would be offensive even if it were true, but it is utterly false. The stock market has been on a 10-year run of steady gains that began in 2009, the year Barack Obama was inaugurated. But why would anyone care about that? It’s only an unarguable, stubborn fact. Still, speaking of facts, there are so many measurements and indicators of how the economy is doing, that those not committed to an honest investigation can find evidence for whatever they want to believe. Trump and his most committed followers want to believe that everything was terrible under Barack Obama and great under Trump. That’s baloney. Anyone who believes that believes something false. And a series of charts and graphs published Monday in the Washington Post and explained by Economics Correspondent Heather Long provides the data that tells the tale. The details are complicated. Click through to the link above and you’ll learn much. But the overview is pretty simply this: The U.S. economy had a major meltdown in the last year of the George W. Bush presidency. Again, I’m not smart enough to know how much of this was Bush’s “fault.” But he had been in office for six years when the trouble started. So, if it’s ever reasonable to hold a president accountable for the performance of the economy, the timeline is bad for Bush. GDP growth went negative. Job growth fell sharply and then went negative. Median household income shrank. The Dow Jones Industrial Average dropped by more than 5,000 points! U.S. manufacturing output plunged, as did average home values, as did average hourly wages, as did measures of consumer confidence and most other indicators of economic health. (Backup for that is contained in the Post piece I linked to above.) Barack Obama inherited that mess of falling numbers, which continued during his first year in office, 2009, as he put in place policies designed to turn it around. By 2010, Obama’s second year, pretty much all of the negative numbers had turned positive. By the time Obama was up for reelection in 2012, all of them were headed in the right direction, which is certainly among the reasons voters gave him a second term by a solid (not landslide) margin. Basically, all of those good numbers continued throughout the second Obama term. The U.S. GDP, probably the single best measure of how the economy is doing, grew by 2.9 percent in 2015, which was Obama’s seventh year in office and was the best GDP growth number since before the crash of the late Bush years. GDP growth slowed to 1.6 percent in 2016, which may have been among the indicators that supported Trump’s campaign-year argument that everything was going to hell and only he could fix it. During the first year of Trump, GDP growth grew to 2.4 percent, which is decent but not great and anyway, a reasonable person would acknowledge that — to the degree that economic performance is to the credit or blame of the president — the performance in the first year of a new president is a mixture of the old and new policies. In Trump’s second year, 2018, the GDP grew 2.9 percent, equaling Obama’s best year, and so far in 2019, the growth rate has fallen to 2.1 percent, a mediocre number and a decline for which Trump presumably accepts no responsibility and blames either Nancy Pelosi, Ilhan Omar or, if he can swing it, Barack Obama. I suppose it’s natural for a president to want to take credit for everything good that happens on his (or someday her) watch, but not the blame for anything bad. Trump is more blatant about this than most. If we judge by his bad but remarkably steady approval ratings (today, according to the average maintained by 538.com, it’s 41.9 approval/ 53.7 disapproval) the pretty-good economy is not winning him new supporters, nor is his constant exaggeration of his accomplishments costing him many old ones). I already offered it above, but the full Washington Post workup of these numbers, and commentary/explanation by economics correspondent Heather Long, are here. On a related matter, if you care about what used to be called fiscal conservatism, which is the belief that federal debt and deficit matter, here’s a New York Times analysis, based on Congressional Budget Office data, suggesting that the annual budget deficit (that’s the amount the government borrows every year reflecting that amount by which federal spending exceeds revenues) which fell steadily during the Obama years, from a peak of $1.4 trillion at the beginning of the Obama administration, to $585 billion in 2016 (Obama’s last year in office), will be back up to $960 billion this fiscal year, and back over $1 trillion in 2020. (Here’s the New York Times piece detailing those numbers.) Trump is currently floating various tax cuts for the rich and the poor that will presumably worsen those projections, if passed. As the Times piece reported: