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Efhw antenna counterpoise

efhw antenna counterpoise An important difference is that it . 5:1 in the voice segments. Oct 19, 2009 · A simple, useful tuner for the venerable EFHW. I have to be careful not to touch any metal in the station (like the bug or the antenna tuner roller) when transmitting or I will get an RF burn. As a home-unit resident the size of a full half-wave is pretty impractical, but I decided to try it so I had a base-line to compare future shortened verticals to. 30 Watts QRP, 40-10 Meters, 66 feet. If you find that common mode exists after you install the EFHW end fed half wave HF antenna, a Grounded Counterpoise wire can then be attached to the barrel connector at the antenna‘s feed point, which can be secured with a stainless steel hose clamp. Would both setups be considered as counterpoise for the antenna ? Mar 11, 2007 · 2007-03-11. The coupler was tuned to resonance on the bench first using a resistive load. This would require a good ground as counterpoise, but that was not a problem, as I had provided this already for the EFHW feedpoint by a copper strip of 25mm wide, ground rod and nets. They also have become bathed in misinformation, mystique, and contradiction. 0 (20 meters) 7. No ground plane or counterpoise is needed so portable operation . A half-wave at the lowest band of interest will also work well on all harmonically-related bands which has become particularly attractive to those wanting a quick portable wire antenna. Feeding an End Fed Half Wave Antenna ½ l •May work (somewhat) since the coax shield acts as a counterpoise: •Coax shield provides the return path for the RF field •Performance will vary with X, proximity to ground, etc •SWR losses on the coax can be a problem •Tuner needs to be at the base of the antenna X RF Field Tuner The antenna is designed to work without a ground plane or counterpoise – it uses the outer of the coax as the return path for the minimal antenna currents. Grounding a Counterpoise on End-Fed Half Wave Antenna. Since it's not always practical to "hang around" at . EFHW Counterpoise Current flowing into the antenna's end must be equaled, at that end point, by the same amount of current flowing into a ground or counterpoise of some type. Sota Mountain Goat is an award for accumulating 1000 activator points from mountain summits (see post). 47 wavelengths. I wanted an antenna that small and lightweight! Aug 17, 2021 · 20m End Fed Half Wave (EFHW) Build. The SWR for the 20 meter EFHW antenna was < 1. May 01, 2021 · Multiband End-Fed Half-Wave EFHW Antenna. A very simple antenna to make, deploy and use is an end fed wire antenna. 2:1 Jul 07, 2020 · Grounding per NEC is always recommended but an EFHW does not require any ground and adding ground or counterpoise wires will probably not improve anything. The antenna was deigned for the ham radio bands of the day: 160, 80, 40, 20 and 10 metres. Jul 19, 2016 · More on the EFHW Antenna. by admin on August 17, 2021. If a support is not available I use the 31 ft Jackite fiberglass pole and a drive-on mount or alternatively dropped over a driven T-post. Aug 09, 2021 · Grounding a Counterpoise on End-Fed Half Wave Antenna Posted date: August 09, 2021 in: Antenna Laurence, WA2TLY, is asking some questions about a few aspects of the EFHW 80-10 antenna, Why they are there and what they are for? Aug 08, 2021 · Grounding a Counterpoise on End-Fed Half Wave Antenna. Either use a "counterpoise" at least 0. Sep 14, 2018 · For comparison here is the gain of a 1/4 wave Diamond antenna on the same HT with and without a counterpoise. Like. This gave an SWR of about 3:1. I finally decided to try an End Fed Half Wave Antenna (EFHWA) and was pleasantly surprised! Just before 14:00 on Saturday 14th of July 2012, I heard Barrie ZS6AJY, first present on the CW Net, frequency, 7020 kHz CW. The main one is that the antenna feed impedance is around 2500 ohms and very little RF current flows into the RF earth or counterpoise. The blue dashed plot is the Diamond SRH77CA antenna paired with the FT1D with no additional counterpoise wire. I then raised the end of the antenna and tied it to a convenient bush. Its best to use a good common mode choke balun in the feedline near the antenna, maybe 5 to 20ft down the coax from the matching transformer. For the antenna I cut about 10m of wire for the 20m band and just 1m for the counterpoise. Dec 22, 2020 · I'd like to know, if a DC grounded EFHW antenna mounted on top of a 20 ft. 160M Folded Counterpoise. Antenna system: RHF Single Band HF Mobile Antenna fitted with 3/8th thread (also know as a Hamstick) Chameleon Jaw Mount (Hamstick mount) 105ADT Heavy Duty Stud Mount 3/8 Fit Optional items. Previously that inverted L "stealth" antenna had been worked against a The End Fed Half Wave Antenna - Free download as PDF File (. 05 wavelengths and about 0. In the case of the "EndFedz" EF-10/20/40 and its clones, where we are effectively using the coax as a counterpoise, we can meet this requirement by ensuring the feeder is at least 0. perspex squid pole center support. Nov 17, 2010 · The End Fed Half Wave antenna described is a very good choice for those operators who have limited space and require an effective radiator. Apr 09, 2021 · Place it along the coax about 13-feet from the antenna transformer, this is about 0. Results are encouraging but tuning them up can get a bit fiddley. Any counterpoise should be at least 1 foot above ground running away from or perpendicular to the antenna wire. Antenna winder: TET-Emtron (Perth), Squid Pole: Harverford (Sydney) EFHW antenna 15/20/40 metres and winder. 05 wavelength wire to EFHW antenna. -wave antenna. 1. The antenna tuner needs a 0. Feeding an End Fed Half Wave Antenna ½ l •May work (somewhat) since the coax shield acts as a counterpoise: •Coax shield provides the return path for the RF field •Performance will vary with X, proximity to ground, etc •SWR losses on the coax can be a problem •Tuner needs to be at the base of the antenna X RF Field Tuner Aug 28, 2019 · Adding 0. At least in Colorado, many of the winter activations are harrowing experiences in cold weather, deep snow, and high wind. End-Fed Half-Wave Antenna & Tuner. of twin-lead wire with one of its wires soldered to 33. Dec 25, 2010 · Some commercial EFHW antenna manufacturers sometimes state that a ground/counterpoise is not needed (except for safety/lightning protection; true). Enter the desired frequency. Whether you`re QRPbackpack, vacationing, emcomm station, or an antenna neighbors will never see, MFJs got an EFHW for you: MFJ-1982LP, $59. Observe established safety practices when working with antennas, and avoid proximity to power or utility wires. There are two main benefits in using an end fed half wave antenna over a co-ax fed half wave dipole. UHF Connector Socket Antenna system: RHF Single Band HF Mobile Antenna fitted with 3/8th thread (also know as a Hamstick) Chameleon Jaw Mount (Hamstick mount) 105ADT Heavy Duty Stud Mount 3/8 Fit Optional items. 5 Watts working into the 20. In this configuration, the coax shield will act as your counterpoise. 0 x 3 = 21. The best way to resolve this is to fit a choke, such as 10 turns of RG213 on a four Aug 08, 2021 · Grounding a Counterpoise on End-Fed Half Wave Antenna. No ground plane or counterpoise is needed. Flip. The End Fed Half Wave antenna or the popularly known EFHW antenna has been around almost ever since the inception of HF radio. The described antenna is based on the widely used end-fed half-wave (EFHW) dipole antenna design, improved for a bigger variety of bands, . We model a 67 ft EFHW wire for example, and vary the “counterpoise” from 2 ft down to 0. They are more prone for problems near noise sources or consumer gear, and can easily exceed FCC RF exposure limits with surprising low power levels. the antenna will be worthless and not make contacts, it simply means something else replaces the missing counterpoise area and we also bring RF fields right into the shack. My take on a QRP HF EFHW inverted V antenna designed for use on five amateur radio bands… The 17 foot side is sometimes called a "counterpoise. Can be fed with a broadband high-impedance transformer for multi-band use. A similar process was undertaken for the counterpoise. A "counterpoise" in the . Note, I built mine into an old modified MFJ945e antenna tuner with built in cross needle SWR meter. 230 MHz. Various dipoles vs. The reason for that is simple, end-fed half waves have problems that affect consistency of user results. The key to end fed antenna success is the matching network interface between the long wire antenna and the coax feed line and feed line choke at the transceiver. Details for the W3EDP antenna are quite straightforward, and it is basically another version of an end fed wire antenna. A half wave end fed is a high voltage low current antenna, and everything around the antenna will affect its impedance and balance, obviously the counterpoise will have a large effect. Ham Radio. Mar 11, 2007 · 2007-03-11. Nevertheless, the EFHW antenna had in the past, been rather sparingly used by amateur radio operators due to various reasons. Laurence, WA2TLY, is asking some questions about a few aspects of the EFHW 80-10 antenna, Why they are there and what they are for? January 19, 2021 …. 3:24 turns ratio on a FT140-43 toroid with a 150pF capacitor across the input. 2/MHz, m = 15/MHz) or connect the side opposite the antenna to the system ground (return). They rely on the uncontrolled, random capacitance between the coax feedline shield (or your body/radio) and the lossy soil to complete the circuit. Despre antene in jumatate de unda Jul 19, 2012 · An end fed half wave antenna for RaDAR. Laurence, WA2TLY, is asking some questions about a few aspects of the EFHW 80-10 antenna, Why they are there and what they are for? Watch to learn more. 05 wavelength counterpoise for an EFHW (just 1 meter on the 20m band), so most of that run down the garden would be guy rope! RG58 coax for a feedline. Surprisingly bad isn’t it. Apr 05, 2019 · My End-Fed Half-Wave (EFHW) The last few years have seen a resurgence of interest in the end fed half-wave wire EFHW antenna. 5 metres to 6. qrznow. If the end fed antenna (half wave) is not in the clear, then the counterpoise is cut-and-try. This is basically a half wave dipole that is fed on one end rather than in the middle. 0. 0 x 2 = 14. The normal quarter wave ground plane antenna consists of a vertical radiator which is insulated and centered between 4 horizontal surrounding radials which extend out from the base of the antenna. 21. Aug 15, 2016 · Dropping the ability to tune in 160m seems an acceptable trade-off for the advantage of having a shorter multiband end-fed antenna with no counterpoise cables on the ground. Jun 11, 2012 · The only downside to EFHW antennas is the need to cut a different wire for each band. Your unun has integral numbers of turns in its primary (9 turns between the counterpoise and the radio tap) and an integral number of turns in the secondary (27 turns between the counterpoise and the antenna with 9 of the turns common to both primary and secondary). 5 x 8 = 28. This allows simplification of the antenna mounting as with the random wire end fed antenna. It is designed as a highly portable wire antenna, easily set up as an inverted V, horizontal, sloper, or in the case of higher frequencies, a vertical radiator. 6 Watt ERP using my trapped 80/40/20 HWEF. 25MHz, then I removed the resistor and attached the half wave antenna (6. Put. com. 0 (10 meters) So right there, cutting the wire for 80 meters gives you 6 or 7 bands. com EFHW-8010-1K and put it up temporarily to run some tests on it. Electronics-notes. On the receive side, the standard 160 meter antenna is a Beverage of some . You can also use the unun with no counterpoise or ground if your feedline is at least 25+ feet long. Three turn primary from the radio and 24 turn secondary with a capacitor across it. Oct 20, 2018 · According to some sources (ref. What followed was 3 months of confusion, learning and experimentation. g. 05 wavelength wire. This brought the SWR down to about 2:1. Nov 11, 2012 · Multiband half wave end-fed HWEF (2012) Yes it’s cheap, easy to build, doesn’t need radials and it works GREAT! It sounds to good to be true. a multi-band end fed half wave (efhw) aerial for sota As a super simplistic aerial option the End Fed Half Wave (EFHW) aerial just about takes the biscuit. Engineering. This video clearly explains the process of making a "Rat Tail" antenna extension for your HT. We built it in the ARRL Lab, set it up outside, trimmed the wire for the lowest SWR, and got it on the air. I recently acquired an intertest in Slow Scan TV (SSTV) and one of the most popular frequencies for SSTV exchanges is 14. 20-30 feet but NOT resonant. Wire Connector The Wire Connectors are terminal lugs located at one end of the Antenna Wire (b) and Counterpoise Wire (k). " Here's my "take" on the antenna's operation, along with a suggestion or two: To begin, the "counterpoise" isn't a real counterpoise, or at least it doesn't function like the usual counterpoise (except on 20 meters). The final turns ratio turned out to be 3:29. 8 metres long, the VSWR is less than 1. 5mm. Describe your experience with the MyAntennas EFHW-8010 8-band End Fed Half Wave antenna and tell us why you give it the rating you did (required). single wire for a total length of . The Line Winder is used to store the Antenna Wire (b) and Counterpoise Wire (k). The deal with a counterpoise is that an equal amount of voltage is present as on the antenna itself and unlike radials, there is only one, so no distribution of that voltage amongst them. It can be much simpler, the toroid and capacitor in a suitable little plastic box. Nov 09, 2020 · Grounding a Counterpoise on End-Fed Half Wave Antenna. Without an earth the antenna will try and use the coax as the return path. 05:1, was the lowest of all three antennas since the transformer was tuned for impedance match at 30 meters. Mar 29, 2018 · QRPGuys No Tune End Fed Half Wave Antenna - QRPGuys. Mar 06, 2021 · Antenna Project – HF QRP End Fed Half Wave. 8 metre length of wire mounted as an inverted V, a non-resonant 6. The end fed half wave antenna can be operated with a small counterpoise, and in some instances, no counterpoise is used at all, although this is not necessarily wise. These are truck camping alternatives only! 160M Folded Counterpoise. Homebrew HF EFHW antenna for low power SOTA, Parks and field day events. Can be vertical or horizontal (or both). Fishing bag 150mm Counterpoise (quarter wave length) Antenna tuner Feeder Sep 20, 2019 · Short EFHW(End Fed Half Wave Antenna) 80-10m Band Pada kesempatan kali ini, coba sharing pengalaman step by step merakit komponon UNUN 1:49 dengan menggunakan Toroid FT240-43 dan Kawat Email 1. Read more on qrznow. 3:1) on 80m and 40m, and be. Posted date: August 08, 2021 in: Antenna. Feb 28, 2021 · I could run a counterpoise wire away from the mast at an angle to the bottom of the garden & choke the coax at the base of the antenna. With the EFHW the earth (or a counterpoise) is still important, but not quite as crucial. 10-wavelength on 80M and will allow the shield of that coax to be the "counterpoise". 30 Watts QRP, 80-10 Meters, 132 feet. Oct 15, 2020 · End Fed Half Wave Antenna Kit for 10/15/20/40 Meters ARRL has partnered with HF Kits to bring you this easy-to-build 4-band antenna kit: an end-fed half-wave (EFHW) antenna. 05 wavelength wire inline with the half-wave radiator. UHF Connector Socket . In many applications the coax feed to the antenna matching unit will act as an efficient counterpoise. aluminum pole or being mounted to a satellite bracket on the side of the wall at the same height, but with a ground wire running from the bracket to an earth rod dug in the ground. May 27, 2020 · The transformer was attached to the 30 meter EFHW antenna and turns were removed for best match to 50 ohms. Step 4 After drilling all the holes, attach the coax connector and counterpoise connection (see 3A) and strain relief and long wire antenna connection (see 3B). forums at the upcoming Prescott, AZ Hamfest on May31 to June 1, 2019. For the on-going 2007 ARNSW Homebrew Group Challenge work I needed a simple 80 metre antenna. Apr 13, 2017 · Antenna Alchemy - End Fed Half Wave Antenna and The Way of the Goat. Armed with technology it was time to revisit this “no-tune” portable antenna. Jan 09, 2017 · Topics covered were the basics of EFHW antennas by Steve Yates AA5TB including lengths, design and installation of the antenna. 05 wavelength counterpoise to work properly. I experimented by attaching a load resistor between the output and ground for a range of possible antenna impedances from 2200 to 6800 ohms. 3. May 03, 2019 · More Experiments with EFHW Antennas – Part 2. Lumayan berat untuk nge-lilit email pada inti toroid, diperlukan banyak kesabaran dan teknik dalam "menyulam" kawat email supaya bisa melilit pada . The feed line, as well as everything connected to and surrounding the single-wire feed line and counterpoise, becomes part of the radiating system. Steve AA5TB has presented a similar graph, showing instead both R and jX. Aug 12, 2016 · Actually, the 9:1 ratio is kind of magic, because 9 is the square of an integer. a home made end fed half wave antenna coupler with antenna lenght calculator and counterpoise calculator based on center frequency includes pictures and drawings along to antenna homebrewing instructions with a home made on air wound transformer. txt) or view presentation slides online. Antennas for 160 meters on a standard half acre (~100 x 200 ft) suburban house lot pose quite a problem. Using a 19. The coax connector is at one end of the dipole, where it is most needed. Conventional wisdom has it that you must have an earth on a vertical antenna. ) Figure 2A (top) and 2B (bottom) – Typical EFHW Installations The EFHW’s SWR will be affected by height above ground, type of ground, feed line interaction, and any nearby conductive surfaces. If possible, run the counterpoise away from or perpendicular to the antenna wire. End-fed halfwaves have become increasingly popular. As part of my research for the talk, I obtained a MyAntennas. The SWR for 30 meters, 1. com • 4h. This was a quick test, but interesting . the conductorg eon- nected to the tower- acting ag a counterpoise, or an counterpoise attached to the tower to provide the Image Function. In many applications the co-ax feed to the antenna matching unit will act as an efficient counterpoise. Below the result of a 30 minute daytime session on 40m in WSPR mode with 0. 1), an end-fed half-wave antenna needs a 0. Par EndFedz® Antennas are low-power End Fed Half Wave (EFHW) antennas with the match box coax connection at the end of the wire, for convenient and quick stealth portable operations. Fishing bag 150mm Counterpoise (quarter wave length) Antenna tuner Feeder Jun 06, 2003 · the counterpoise to an inverted L antenna which was operated against those counterpoises as an all-band antenna fed by a "tuner". My 270 foot Off-Center Fed Multiband has a Standing Wave Ratio (SWR) of 3:1 on 14. not "gomething acts a substitute for the Of the The Image function may be provided by ground, the tower- an extension of ground, the tower and bean above the feed point. What I discovered is that it provides a good SWR without a tuner on 40, 20, 15 and 10 meters. Using the gear explained in the previous article about these end-fed dipoles, I performed one run with an additional piece of “counterpoise” wire 0. Even with this counterpoise the station is still very hot with RF when operating high power (more than 1kW output) on 160m , due to the proximity of the antenna, which is only 27 ft away. In spite of what some manufacturers will tell you, an end-fed 1/2 wave ALWAYS has a counterpoise. 05 wave lengths long (ft = 49. Laurence, WA2TLY, is asking some questions about a few aspects of the EFHW 80-10 antenna, Why they are there and what they are for? Jan 04, 2017 · Part 2 – A 40 Meter EFHW with a “Radiator” wire and various length “Coax-as-Counterpoise” wires is analyzed – We will see that the common-mode current is almost always LARGER on the coax shield some distance away from the feedpoint, which is why the “counterpoise” radiates and is called “the other half of the antenna”. At 19. Probably the most familiar is the end fed half wave antenna (EFHW) But random length or non-resonant end fed antennas are also popular and effective, especially for portable use. f. In fact many use this antenna indoors and it works well, but antenna location is always a compromise of some sort. It’s pretty easy to get 1. Apr 18, 2020 · Length of counterpoise should be a minimum of 30-40 feet but not the same length of the antenna wire. These are truck camping alternatives only! Dec 11, 2016 · The counterpoise connects to the ground side of the unun and lays on the ground parallel to the antenna wire, just as in version 2. Can be fed with a 1/4 wave ladder line, but will be single banded. Jul 19, 2012 · An end fed half wave antenna for RaDAR. The measures used were exactly one half of those used for the W3EDP: 8. 0 (10 meters) You get 4 bands in one antenna, and you get the idea. Laurence, WA2TLY, is asking some questions about a few aspects of the EFHW 80-10 antenna, Why they are there and what they are for? End Fed Half Wave Antenna Coupler Schematic – 7‐30MHz . The lower end of the antenna may also be grounded as an alternative to reduce static noise. EFHW Antenna is a great compromise if you have limited space and with only 23m wire i can cover from 80m up to 10m bands with acceptable performance. one with 0. The end fed antenna system works well in horizontal, sloper, and vertical configurations. (Counterpoise length and orientation will affect SWR. 8 Agustus 2021 1 Dilihat. Oct 05, 2016 · An end-fed halfwave, often referred to by the acronym EFHW, seemed to be a good choice, as it only requires a support at the far end. If you start with a half wave wire for 40 meters to save space: 7. The outside braid of the coax acts as a counterpoise, so it’s important to have the coax on the ground for at least 16’, but again, this is a variable that is not etched in stone. 0 x 4 = 28. Steve Yates – AA5TB has written a good piece on the care and feeding of the End Fed Half Wave antenna. Aug 08, 2014 · QRP Multi-band HF EFHW antenna for SOTA Post updated 29 September 2017. The upside to EFHW antennas is no long counterpoise. Multiband End Fed Half Wave EFHW Antenna » Electronics Notes. Being fed directly from one end and with, potentially, no need for a counterpoise the EFHW is as simple and as light as an aerial can get. ) The EFHW’s SWR will be affected by height above ground, type of ground, feed line interaction, and any nearby conductive surfaces. End-fed half wave antennas are best for temporary antennas using low power and batteries, far from power mains and noise sources. 8 metre counterpoise, this antenna is resonant in the 40/20/15/10m bands. Aug 08, 2021 · Grounding a Counterpoise on End-Fed Half Wave Antenna Cyber Man 8 Agustus 2021 International , QRZ Now 44 Views Laurence, WA2TLY, is asking some questions about a few aspects of the EFHW 80-10 antenna, Why they are there and what they are for? A very simple antenna to make, deploy and use is an end fed wire antenna. I have changed the counterpoise wire from 1. It’s been a couple of years now since my first post on EFHW Antennas. With the tuner in my xiegu x5105 I can also use it on 30, 17, 12 and 6 meters. Testing has shown this is ideal for performance, and reinforces the idea that the EFHW is more accurately described as an "extremely off-center fed dipole". 2:1 For reception such antenna can be used, but all the interference generated in the house is coupled to the antenna: the counterpoise is electrically polluted and this interference is in series with the received signal. If you do have RF problems you can connect an earth or short (1m) counterpoise to the earth (green) terminal. These single-band and multi-band antennas can be mounted horizontally, vertically, or as a sloper. I saw photos that Steve WG0AT had posted on Facebook of his little EFHW, with the matching unit built into a dental floss container, for a light and compact solution. You need to put a lot of attention during the build of the 1:49 transformer. KI6SN's November 2009 Trail-Friendly Radio column in WorldRadio Online magazine focused on a useful, popular and easy-to-manage HF field antenna: the EFHW - or End Fed Half Wave, with a counterpoise. Listed under the Antennas/End-Fed/End Fed Half Wave Antenna category that is about EFHW End Fed Halfwave Antenna. Each counterpoise was "tuned" to length by adjusting for maximum current in the countepoise for that band. The antenna is fed via coaxial cable and passes through a tuned matching . Mar 27, 2015 · I have found the End Fed Half Wave (EFHW) antenna to be the best all-around solution for portable operation. Here’s a series of SWR plots across the HF bands from 80m to 10m . Why Radials or Counterpoise? • An ideal radial system: –shields the antenna from the earth –provides a path for return current –Provides a return path for fields produced by the antenna • A counterpoise provides only the return path –More about counterpoises later Apr 09, 2021 · Place it along the coax about 13-feet from the antenna transformer, this is about 0. pdf), Text File (. End Fed Half Wave Antenna Coupler Schematic – 7‐30MHz . Feb 01, 2009 · A shortened multi-band End-Fed Half Wave (EFHW) antenna for 80-10m The 80-10m EFHW This is a shortened multiband antenna, about 23m long, for 80m-10m that offers low SWR (1. Even though the WSPR mode is very efficient and claims a gain of +30dB compared to . I have built a number of these on different bands and found the design extremely repeatable. After I had established my antennas for many of the HF bands; dipole for 80-40M and Hex beam for 20-10M, I turned my attention to 160 meters. 01 ft and get the following results ===>. Several weeks ago, Doug Hendricks from QRPGuys handed me a prototype kit to try. Tighten each of the screws (see 3C). Both can be used on multiple bands though the random . The main benefit is that the antenna feed impedance is around 2500 ohms and very little RF current flows into the RF earth or counterpoise. Mar 02, 2016 · Link EFHW antenna for SOTA. The "Rat Tail" is simple, inexpensive, and efficient. 05 lambda counterpoise to work correctly. with the far end unconnected. nylon dog-bone end insulator. When used as TX antenna the losses are high and the impedance must be matched to off-resonance frequencies. You could suspend the counterpoise with insulators. So you could have arcing and corona, not just at the ends, but at the high voltage nodes along the wire. Measurements with the VNA showed that this was feasible, but the antenna was at resonance somewhat too inductive. Some people swear by endfed halfwaves, while others swear at them. RG58 coax for a feedline. Aug 23, 2005 · the counterpoise and the radiating element are very nearly equal. My counterpoise is about 50 feet (for an approximately 75 foot antenna) and I can reliably work domestic DX and occasionally foreign DX with only five watts . Jun 01, 2018 · Here’s a photo of the competed unit: My EFHW match box. Figure 6 - SWR vs "Counterpoise" Length vs Turns Ratio for an End Fed Half Wave Free Space Antenna The graph below (fig. When attaching the bolts on the inside of the box, use two tooth lock washers, placing one above and one below the cable lug to prevent it from . Each radial is evenly spaced (90 degrees apart from each other) around the vertical element. Share. . QRPGuys No Tune End Fed Half Wave Antenna – $15 We continue our antenna offerings with this single band, 80m-10m end fed half wave wire antenna. 7) is of actual measured data of an end fed half wavelength antenna with an isolated coupler using a 8:1 turns ratio. I am creating a presentation on "End Fed Half Wave" antennas which will be one of the tech. MFJ-1984LP, $49. Jun 19, 2019 · Yeah, that title is a mouthful! And for something with such a long name, it sure is a tiny little kit. This is the antenna I use the most and it works great. 8 metres long. Typically, performance . The end fed half wave antenna can be operated with a small counterpoise, and in some instances, no counterpoise is used at all, although this is not … 3. Notably since then I have acquired a Mini 600 Analyser. Shorter length counterpoise wires can be used if operation is confined to 40m or higher. This is true with a quarter wave antenna, which needs an extensive ground plane. Other useful information would include your experience with similar products, infomation on a product that you would purchase instead of this one, and so on. It is designed as a highly portable wire antenna, easily set up as an inverted V, horizontal, sloper,. A little experiment with an end fed half wave. 05 wavelengths long at the lowest operating . The slightly modified antenna now becomes a VHF/UHF dipole antenna with significant gain over the highly compromised "Rubber Duck" antenna. 65m) and counterpoise (66cm . These antennas can be mounted horizontally, vertically or as a sloper. I supported the wire on a 4m fishing pole and initially just pegged the end in the ground. The Par End-Fedz ® are a full length half wave dipoles, but with an important difference. End Fed Half Wave Antennas. We continue our antenna offerings with this single band, 80m-10m end fed half wave wire antenna. The This would require a good ground as counterpoise, but that was not a problem, as I had provided this already for the EFHW feedpoint by a copper strip of 25mm wide, ground rod and nets. It is easy to deploy, requiring a single point of support. Voltage and current distribution and the issues this presents, the minimum counterpoise, impedances and turns ratios of end fed impedance transformers. 5m long EFHWA in Inverted Vee form, the . Raising, lowering, or re-orienting the antenna may be enough to . Above, you'll see the schematic for a simple EFHW tuner for the popular 40- and 20-meter CW bands. Dec 11, 2016 · The counterpoise connects to the ground side of the unun and lays on the ground parallel to the antenna wire, just as in version 2. My take on a QRP HF EFHW inverted V antenna designed for use on five amateur radio bands… EndFedZ® Overview. The QRPGuys Mini 80m-10m No-Tune End Fed Half Wave Antenna. It's now available for sale on their site. 5 Ft. Portable operation could not be easier. There are two main benefits in using an end fed half wave antenna over a coax fed half wave dipole. I called him at 2. EFHW antenna components. Aug 04, 2020 · What is an EFHW? 1/2 wavelength long antenna, fed on the end. com DA: 25 PA: 50 MOZ Rank: 19. Link Insulator: 30mm length of 6mm fiberglass rod, salvaged from a UHF mobile antenna. Jul 03, 2017 · Tune for minimum SWR. It works! An. Palomar Engineers employs a dual core matching system that offers wide bandwidth (1-61 MHz), 500 watt PEP rating, and a connection for a counterpoise or ground if desired. If you are setting up a portable station and plan on using no additional "counterpoise" then just hook up all of your equipment. Length of counterpoise should be approx. A lot of literature seems to suggest that you only need 0. Matching is done by a parallel LC network. 2019-07-21 After putting up my 40 meter end fed half wave antenna discussed below and reading comments on Facebook about EFHW antennas I decided to do some testing. 95. Your feed line is essentially the counterpoise, so a separate one is not needed. I was interested in an old zepp antenna that had a counterpoise along side the main radiator. Additional counterpoise is usually not required in this design, although the lower wing nut provides a convenient counterpoise connector if needed. Can be tuned and limited to a single band. Apr 05, 2019 · My End-Fed Half-Wave (EFHW) The last few years have seen a resurgence of interest in the end fed half-wave wire EFHW antenna . Aug 07, 2021 · Grounding a Counterpoise on End-Fed Half Wave Antenna (#494) Laurence, WA2TLY, is asking some questions about a few aspects of the EFHW 80-10 antenna, Why they are there and what they are for? Watch to learn more. 0 (15 meters) 7. Subsc. It enables rapid deployment and recovery of the CHA MPAS 2. End-fed horizontal wire, an EFHW, offers the perfect solution for a wide range of ham activities. That is it. 230 MHz before tuning so I was looking for better efficiency. antenna. counterpoise wire can be up to ¼-wavelength long and should be approximately under the antenna wire with the far end unconnected. If you don't specifically provide one then the coax shield will Figure 3 - Impedance versus "Counterpoise" Length for an End Fed Half Wave Free Space Antenna Figure 4 - Two Half Wave Length Conductors End-To-End for Determining Resonance in Modeling In figure 3, particular attention to the points where the impedance is purely resistive (jX = 0 ohms) at 0. Oct 03, 2016 · The extra wire supplies the missing half of the HT's antenna. EIRP measurement of laboratory reference dipole, FT1D stock antenna and Diamond SRH77A antenna. 1:1 with this setup but don’t leave the counterpoise unconnected! The counterpoise can simply lie on the ground. We can see that the magnitude of the impedance approaches infinity as we make the counterpoise progressively shorter. The number of variations are endless. Although it is simple to build and is a multiband . I have inserted two additional links for coverage on 17m and 30m. efhw antenna counterpoise