They also perform very well and usually beat a compromise antenna hands down. (The 33'3″ segments are not used. Second, the high current part of the wire, which does most of the radiating, is a quarter wave from the feedpoint, which can usually be much higher than the feedpoint. This is a 200W version of popular EFHW-8010 End-Fed Half-Wave (EFHW ) antenna for 80/40/30/20/17/15/12 and 10m bands. It is a resonant Half wave on 40m (7MHz) therefore also resonant on second, third and fourth harmonics. EFHW-60S-1K Single band End Fed Half Wave Antenna This is an End-Fed Half-Wave (EFHW*) antenna for 60m (5. HyEndFed 3 Band + Spiderbeam 12m Pole = Easy and Effective HF Portable Vertical Antenna - Duration: 15:33. This was cured completely in the 2012 IMD event. 8-2 MHz) operation, an antenna with an electrical length of 74 feet should suffice and should be trimmed to give a quarter wave resonance at 3. These can be buried - the exact length of the radials is not critical, but more, shorter radials are better than fewer, longer ones. Easy Storage/transport. Ground losses increase off the resonant frequency and efficiency suffers- cut it precisely for your SOTA freq. They are not very rigid at the tip, so it does not really make much difference whether they are guyed 1m, 2m or 5m above the ground, 1m above the ground is just fine. Foremost, I see a lot of EFHW's with a little grounding lug on the side of the matching network enclosure. My house is on a slab and there is no visible ground rod anywhere around the house. I had a BN43-202 core in stock and attempted to try to create a small QRP EFHW transformer from 7 - 29 MHz. In that case, expected efficiency (meaning PowerOut/PowerIn) of the transformer was less than 65% at 3. These values assume that the antenna tuner is placed at the feed point of the antenna and that a suitable ground is provided. I have been offered input VSWR curves. World's Largest Supplier of Amateur Radio, Ham Radio, and Communication Equipment. Describe your experience with the EFHW-8010 8-band End Fed Half Wave antenna and tell us why you give it the rating you did (required). net provides recognition and enjoyment to the people who use, contribute, and build the site. These are the points where the antenna is resonant, at 0. EFHW makes a great emergency back-up for your regular antenna. Our collection of ULTIMAX antennas have been used by DX Expedition Teams, Boy Scouts of America, in military field operations, by the Chile's Civil defense, Israeli military personnel, as well as special event stations aboard the USS Alabama. This unit does not provide a DC electric ground. 3m wire this makes a nice 40-10m antenna. Using a watering can, even children can sink an 8 foot ground rod into the ground. It is resonant Half wave on 80m (3. A ground rod from the braid side of the feedline at the transformer is a good best practice. Figure 1 below shows the business end of the end-fed dipole with source and series reactance Xs (a capacitance) combine to yield a 50 ohm feed impedance for the source. So I put up a separate 20M EFHW (33'-3" long) for testing on that band. " Fitting perfectly fine with the definition of a dipole , you can, at least by definition, feed a half-wave dipole anywhere along its length and have a radiating structure. To connect it to the radio I needed a Balun. 5MHz) therefore also resonant on second, third and fourth harmonics etc. Sloping EFHW Antenna? To answer the question, a wire antenna model was developed* based on data reported by Danny Horvat, NE4XA and E73m (MyAntennas. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. QRPGuys Portable 40-30-20m Tri-Band Vertical Antenna - $20 With permission from Joe Everhart, (N2CX), we have adapted his 40-30-20m portable vertical antenna design using switched toroids for the base loading inductance into a lightweight antenna for an easy outdoor setup. Hi, Thanks for all previous help on my antenna questions. / NO TUNER needed / wire not included/one End Insulator included Product Description MEF-330-1K Multi Band End Fed Half Wave Antenna Transformer This is an End-Fed. The Shunt-fed Tower, an effective Low Band Antenna, uses your beam as a capacitive top-hat and only needs a simple feed network and a good ground system to work DX on 80M and 160M. What's this ideally used for? Am I supposed to attach a counterpoise wire of sorts here? Or is this for attaching a short braided ground strap and physically Earth grounding the antenna with a spike shoved into the ground?. No yagi antennas in the air, crappy coax, no preamps, no amplifiers. I found that putting 220pf in parallel with the input (TX side) brought my 20M SWR down to 1. 8 - 30 MHz and connects between your rig and a random length of wire or a connecting ground wire. Multiband end fed antennas 3. 12 dBi down to 2. While the feedpoint resistance of the EFHW is quite high, the radiation resistanc e is approximately the same as a half wave dipole, 73 ohms (the EFHW is essentially a half wave dipole fed at the end instead of the center). Post #1233. The EFHW or End Fed Half Wave antenna is another great antenna for field use as it only needs a single elevated endpoint (Tree or Fishing Pole). 5mm is a minimum. Photo 1 - Field Day 2007; Photo 2 - Field Day 2007. As with most antennas, the higher the wire, the better the signal. This element is connected directly to four ground mounted radials as with the driven element. When the feedline is connected to the center of a half-wave antenna, the feedpoint impedance is theoretically 72 ohms, which is a good match to both 50-ohm and 70-ohm coax and the. Different setup locations can produce different results. Configure your HF receive antenna setup for optimum performance with our high-quality HF receive antenna system devices. End-Fed Antenna projects and plans is a curation of 60 resources about , N2CX on End-Fed Halfwave Antennas, Endfed wire antenna tuner by KC8AON, QRO End Fed Half Wave Antenna Coupler, W3EDP Antenna, End Fed Half Wave Antenna Coupler. We feature an expansive assortment at competitive prices. QRPGuys Portable No Tune End Fed Half Wave Antenna - $20 We continue our antenna offerings with this single band, 80m-10m end fed half wave wire antenna. Hams claim end feds are; noisy, they cause interference and a good earth ground and an ATU is required. " Fitting perfectly fine with the definition of a dipole , you can, at least by definition, feed a half-wave dipole anywhere along its length and have a radiating structure. Certainly the complex impedance at the end of the EFHW will change and I would bet my shoes that it will be out of the 1:2 SWR range of my back yard setup the wire has been cut to and the transformation rate of the UNUN was tuned to. Remote Matching Units for HF VerticalAntennas EFHW matching transformer Control Consoles Interface cables, TX gear Jumper cables, TX gear Band Pass Filters 200W PerfoBox 500W PerfoBox 1500W Contest Series PerfoBox. a half wave antenna has a high impedance feed point this can be matched using a 1 4 wave stub matching section and converts the 40m vertical into an l shaped 20m j pole antenna the 300 ohm feeder used for this purpose must be kept away from the ground. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. Details are shown in the next two images: Steve Ellington’s antenna: 133 ft. KI6J EFHW Manual. This was 9m vertically metres up a fishing pole and then about 5. On the 1:9 torroid is a ground connection, use an wire or several if you can and just put them on the ground minimum length the same as the coax should be long, or longer. It is resonant Half wave on 80m (3. If someone would like to produce radiation charts based on the dimensions discussed and for various heights above ground, I am happy to include the charts here. The J-pole and other end-fed Hertz antennas are prime examples of antenna that can have severe feed line common mode current problems. The Stake Stick Vertical. PAR/LNR EFHW antenna. Post #1233. Even keying the microphone and saying nothing resulted in noise on 40m. I like half wave dipoles. (The 33'3″ segments are not used. I'm confused about the requirements for a counterpoise for an end-fed wire antenna. It requires no radials and has worked well for me. The EFHW can effectively be deployed like an inverted V which means a 40m EFHW can work with a 6 -10m telescopic fishing pole. 1 VSWR on 160 meters all with NO TUNER !!. 2dB and the balun itself will probably also give a loss of 0. Mounting ham radio antennas in the attic. 2001 The 40 Meters band stealth vertical antenna by K7ZB “You’re 30dB over 9 here…” So goes the consistently fine signal reports received from around the USA and beyond – on 40 meters at the peak of Sun Spot Cycle 23. Link Dipole is a Home Brew EFHW is an LNR 40-20-10 Power : 200 mW. I haven't found a better way to model an EFHW in NEC2. I soldered together two small pieces of tinned G10 double-sided circuit board together and constructed the SWR bridge and associated switch using classical "ugly style" construction. Add coax feedline -- get on the air!. Daniel S • February 17, 2019 2:08 AM It seems to me that the main problem is not that the cable has the properties it’s got, but that any device plugged in to the port automatically gets. antennas bay area hikes bay area hikes with dogs climbing cw difficult drive-up easy efhw equipment ft-817 ft-891 hard hikes hiking learning man portable Morse code mtr-3b mtr3b northern sierra palm pico paddle portable qrpguys qrpguys tri-band vertical san benito sf bay area sota trail running ultralight w1 w6 w6 sota w6/nc-174 w6/nc-209 w6/nc. This was 9m vertically metres up a fishing pole and then about 5. Hi Michael, Definitely a typo, I am unsure why I have 1. If you don't specifically provide one then the coax shield will. 25m of thin 7 x 0. My take on a QRP HF EFHW inverted V antenna designed for use on five amateur radio bands…. Tuning is fairly easy on the lower bands, but is quite challenging on 10m-15m due to the significant effects of hand capacitance at those frequencies. Ground losses increase off the resonant frequency and efficiency suffers- cut it precisely for your SOTA freq. 2dB but you will still have your needed 40% increase in power. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. The jury is in. And, the impedance and reactance are perfect! Below is a quarter wave ground plane antenna I made for 23cm, 1296MHz which is made from off-cuts of household mains copper wire and a scrap BNC socket from the junk box. EFHW-8010 Multi-Band End Fed Half Wave Antenna-NO TUNER NEEDED! This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. While 1/8th wave works reasonably well, better coverage is obtained if the antenna is mounted at about 1/20th wavelength above ground. I have one EFHW 130 foot antenna that is a horizontal antenna. Take a moment and see this excelent video about your station grounding and many more. 18 thoughts on “ NVIS Antennas ” Leonard Hunsicker on August 26, 2019 at 3:06 PM said: I have been using a 1/2 wave 75 meter Inv- Vee up abt 17 feet directly above a couple mile long 4-wire barbed wire fence. When SWR is higher than 2:1 or antenna is used on the non-resonant frequency of the wire radiator, power reduction is recommended due to additional mismatch losses and the possibility to overheat the. Figure 1 below shows the business end of the end-fed dipole with source and series reactance Xs (a capacitance) combine to yield a 50 ohm feed impedance for the source. Two distinct advantages of the EFHW: It's high feedpoint impedance means a minimal counterpoise is required and very little power is wasted into the ground system. Use on 160 Meters as Marconi with tuner and ground. Mounting ham radio antennas in the attic. Hendricks 40m - 15m SOTA EFHW Tuner First, familiarize yourself with the parts and check for all the components. To continue with your YouTube experience, please fill out the form below. Due High Impedance feed point, the antenna is less. EFHW makes a great emergency back-up for your regular antenna. 7 SWR and below on most bands. I have noted recently the increasing popularity of the so-called End Fed Half Wave antenna, though the term often includes harmonic operation of the antenna. I have been offered input VSWR curves. Ease of installation appeals especially to me because of my long life of sorrows trying to get lines through trees. All it takes is water and time. I have written many reviews of published EFHW matching transformers, and in most cases the reviews have reported estimated or measured losses that are appalling and not disclosed by the 'designers'. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. The resonant EFHW types do not light up the coax with RF unless you operate them way out of band. static buildup on antennas. EFHW-8010 Multi-Band End Fed Half Wave Antenna-NO TUNER NEEDED! This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. I've also now tried it with my 40m-15m trapped EFHW and it seems to provide an acceptable SWR for all 5 bands. Various installations such as horizontal, vertical, as inverted V, as inverted L etc. A matching device or counterpoise is needed. Setting out to explore the world out of EFHW antennas that have dominated the discussions nowadays. The EFHW - a monoband end-fed half wave for 10m, 20m or any other HF band A practical, cheap monoband vertical antenna that is great for DX and very cheap too. This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. Here is a small collection of EZNEC files of antennas I have interest in. 9 feet for 7MHz. A short length of wire could be used as a ground-connection or counterpoise, if desired. A Hawaii-based Amateur Radio Antenna Blog focusing on the theory, design, and use of homemade antennas. I am also able to compare this data with that from N5CEY who is running a 1/4 wave vertical at his QTH about 20 miles from here. ground plane antenna with radials. End-fed halfwaves have become increasingly popular. The four short (16'7. What's this ideally used for? Am I supposed to attach a counterpoise wire of sorts here? Or is this for attaching a short braided ground strap and physically Earth grounding the antenna with a spike shoved into the ground?. 0 dBd or zero gain). It is a resonant Half wave on 80m (3. The novel thing was that I only built it the day before and it uses a Coghlan camping washing line spool with the string taken off and about 21m of wire wound onto it. Ease of installation appeals especially to me because of my long life of sorrows trying to get lines through trees. The soil here is 99% clay about 8" down so it gets really unpleasant to work in quite quickly. ó , kdyh kdg \rxu pxowledqg hqg ihg dqwhqqd lqvwdoohg khuh lq 6lqjdsruh iru d ihz zhhnv qrz dqg dp yhu\ sohdvhg , xvhg wkh zluh iurp p\ suhylrxv dqwhqqd zklfk lv ihhw orqj ,w zrunv ehdxwlixoo\ , kdyh lw. Some time ago I had several posts regarding an EFHW matchbox which I used to develop a linked end fed antenna as well as some other variations. EFHW matching transformer Сортировать Ascending Descending From A to Z From Z to A New-Old Old-New Показывать 15 24 33 90 100 Eur. John was asking why I didn't just borrow the balun from that to test on the inverted L. An 'Inverted-V' antenna for the main HF bands NOTE: I am still working on this page, so sorry about the spelling, english and the science ! Described is a simple inverted-V antenna which, when used with a balanced ATU, can be used on all the main Radio Amateur HF bands (80, 40, 20, 15 and 10m). Whether you`re QRPbackpack, vacationing, emcomm station, or an antenna neighbors will never see, MFJs got an EFHW for you: MFJ-1982LP, $49. Figure 1 below shows the business end of the end-fed dipole with source and series reactance Xs (a capacitance) combine to yield a 50 ohm feed impedance for the source. 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. Hi, Thanks for all previous help on my antenna questions. All it takes is water and time. Here’s the NEC2 source for the model. Fortunately, EMP protection has been studied by Dennis Bodson, W4PWF, and effective mitigation. K2YWE's Compact 160m Lazy-U Antenna This compact 160m antenna is a half-wave dipole with a vertical section. I've also now tried it with my 40m-15m trapped EFHW and it seems to provide an acceptable SWR for all 5 bands. Note the orientation of the inductor; wider spacing wire turns towards back of unit. This element is connected directly to four ground mounted radials as with the driven element. They write: GNU radio is a popular environment for teachers and developers involved in Digital Signal Processing and exploring new radio architectures. Applying a feed to any antenna in NEC or any electromagnetic simulation software is about a simple a task as can be conceived by placing a “source” of near infinitesimal size inline with a dipole element. Both will work but, I believe, on average the EFHW will be a bit better. Using a watering can, even children can sink an 8 foot ground rod into the ground. Certainly the complex impedance at the end of the EFHW will change and I would bet my shoes that it will be out of the 1:2 SWR range of my back yard setup the wire has been cut to and the transformation rate of the UNUN was tuned to. A long wire and some insulators is pretty easy to carry. This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. EFHW-8010 8-band End Fed Half Wave antenna product reviews by real people like you. The 40m EFHW is physically broken into 3 sections via two insulators inserted so that the first (when viewed from the tuner end of the wire) isolates a 20m EFHW, the next section when added on via a jumper (I use alligator clips and spade lugs) is resonant on 30m and addding the last section makes it an EFHW on 40m. It performs poor above "bad" ground like desert. static buildup on antennas. Feedpoint was placed 1/4 wl down the pole (note: I did not consider the velocity factor here, but it is not very critical if it is off by a foot or so). Here are some observations from using the following antennas for QRP operations in the field. End Fed EFHW-4010-1K 40M-10M wire antenna More Buying Choices $173. During the 2011 International Marconi Day (IMD) event we found that the 20m EFHW antenna caused interference to our other station on 40m. How to Install Ham Antenna Ground Radials. Parts Inventory 1 - Tayloe SWR Indicator kit 1 - T50-6 core (yellow), T94-2 (red) core not used for 40m-10m 1 – poly-varicon, w/shaft and mounting hardware 24” - magnet wire for the toroid. End-Fed Horizontal Wires(EFHW) cover multiple bands with-out traps, stubs, or resonators. The graph below shows the measured VSWR of a 6. Use on 160 Meters as Marconi with tuner and ground. Often, amateur radio operators are looking for alternative locations to install their antennas. Using this tuner, a portable station needs no ground radials and little or no feedline to achieve excellent results. It is a resonant Half wave on 80m (3. The coax will be about 23 cm in total resulting in 22pF. Ease of installation appeals especially to me because of my long life of sorrows trying to get lines through trees. EFHW-8010 8-band End Fed Half Wave antenna product reviews by real people like you. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. Counterpoise wire(s) close to or laying on the ground will couple and become radials with reduced efficiency. Often, amateur radio operators are looking for alternative locations to install their antennas. This page contains various javascript based calculators for electronics. There is a popular myth among Hams and technical writers that USA Standard Broadcast systems require 120 radials. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. Find many great new & used options and get the best deals for HF End Fed Antenna EFHW-8010-1K 1000W 80-10m / NO TUNER NEEDED!! / 130 feet long at the best online prices at eBay!. Here’s the NEC2 source for the model. Counterpoises. Easy to Install and Use KM5M on 23rd Apr 2014 The NI4L end-fed 40-6m dipole antenna is just about perfect for portable operation. Sorry for the interruption. Checking the antenna at the feed point with the Mini60 antenna analyzer showed a bandwidth of 588 kHz with a 1. Great Quality Affortable End Fed, Delta Loop & Windom (OCFD) Multiband Antennas. Ground rods, copper-plated 8 foot steel stakes driven in the ground, might work in such a place if you use an array of them. K2YWE's Compact 160m Lazy-U Antenna This compact 160m antenna is a half-wave dipole with a vertical section. Rugged weather-resistant 50-Ohm matching network. Thus, the EFHW has a decisive advantage of groundwave radiation over long distances, which is not achieved by other radialless antenna shapes. Building an End Fed Half Wave Antenna. My understanding is that radials are only needed for 1/4 waves to create a 1/2 wave antenna. I used a 2' long wire braid and a 1' long stake in the ground to create about 3' (1m) of return ("counterpoise"). Even using a Ruthroff 1:4 balun or an ‘auto-transform’ type voltage transformer works well for for a center fed dipole where the currents and voltages are well balanced. The balun should be a 1:1 type for 50 or 75 ohm. On-air tests have shown the antenna performs well. W5GI Mystery Antenna W5GI Mystery Antenna is a multi-band wire antenna that performs exceptionally well even though it confounds antenna modeling software. Most of the radiation is horizontally polarized and divides like a 4-leaf clover with each leaf being diagonal to the line of the wire. EFHW-8010P- 200W Portable or Stationary Multi-Band End Fed Half Wave Antenna This is a 200W version of popular EFHW-8010 End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. Shipping is UPS Ground or USPS. They are not very rigid at the tip, so it does not really make much difference whether they are guyed 1m, 2m or 5m above the ground, 1m above the ground is just fine. I’ve made quite a few 64:1 transformers on a tiny FT-114A-43 core that will handle 100w SSB and it fits into a box slightly bigger than a Zippo lighter. 89 Until 10/31/19: ICOM IC7610 HF SDR $2968. This is an End-Fed Half-Wave (EFHW*) antenna for 40/20/15 and 10m bands. I made sure first that the circuit board pieces fit properly into the transparent case. It performs poor above "bad" ground like desert. The efhw fixed component doubler definitely works in the field without having to tweek it. If you live in a space restricted location or are under a HOA restriction, you may be able to mount an antenna outside. ham radio - AFTER the zombie apocalypse, The prepp Ham Radio - Ground spike antenna. Place a 1:1 Balun on the Antenna end of the Feedline. Post #1231. Thanks to Jon AF7TS for the suggestion and discussions that led to this article. EFHW-60S-1K Single band End Fed Half Wave Antenna This is an End-Fed Half-Wave (EFHW*) antenna for 60m (5. HF End Fed Antenna 1500W 160-6m / Ham Antenna with 9:1 dual core UNUN / 117 feet. The attached pictures show the setup. It seems to work best when the transformer is from ~1m to 2m from the ground. It is resonant Half wave on 80m (3. A vertical seemed the obvious answer, a naturally low-angle radiator. Second, the high current part of the wire, which does most of the radiating, is a quarter wave from the feedpoint, which can usually be much higher than the feedpoint. 84 KB; Low Cost Lowpass Filter Design Using. I've settled on a EFHW-8010P from myantennas. 1/4 Wave Ground Plane antenna calculator - Build a simple quarter wave with radials. The balun should be a 1:1 type for 50 or 75 ohm. EFHW-8010-P, EFHW-4010-1K etc. I use about 20' of RG8x to the feed point at ground level, which has a 9:1 UnUn and is tied to a ground rod. 25 wave lengths, 0. (As with most antennas, the more height, the better. However, about 2/3 of the total inverted-V signal is lost to ground when compared to a straight EFHW wire at 40 feet; from 6. HF Antennas Especially stealth models for those in an HOA By Dave Land KD5FX. To help debug a little I did use three colors of wire; black for the ground and cathode circuits, green for the signal grid and red for the plate and screen circuits. Red color indicates the stronger radiation on 3D views. An Attic Coaxial-Cable Trap Dipole for 10, 15, 20, 30, 40, and 80 Meters John DeGood, NU3E [email protected] A shortened multi-band End-Fed Half Wave (EFHW) antenna for 80-10m Steve Nichols G0KYA A shortened multiband antenna, about 23m long, for 80m-10m that offers low SWR (1. Driving through the picnic ground, I … Continue reading →. https://www. End-fed horizontal wire, an EFHW, offers the perfect solution for a wide range of All-Band 80-10 Meter End-Fed Half-wave Antennas - MFJ 1982,1984 Cover all HF bands with one single wire and no tuner! to ensure great performance in a wide range of operating conditions. A WebSDR is a Software-Defined Radio receiver connected to the internet, allowing many listeners to listen and tune it simultaneously. Second, the high current part of the wire, which does most of the radiating, is a quarter wave from the feedpoint, which can usually be much higher than the feedpoint. a few contacts out of the country and mostly east coast due to lack of time to talk on the radio. SOTA summits tests. The BNC feed to the shack is at the bottom, the inverted "L" connects to the right and the ground and radials to the left. 3 SWR on 40M using the 40M EFHW. 98 (1 new offer) End Fed EFHW-8010-1K 80M-10M wire antenna with installation kit. These are the points where the antenna is resonant, at 0. Combining the concepts developed in the with those from the ,. Obviously, an EFHW antenna has a "half-wave" length only at one specific frequency: there is absolutely no such thing as a "multi-band end-fed half-wave" antenna. If you are using a tuner that has just one wire coming out of it, then the other half is the tuner's chassis, and whatever is connected to it. We have been receiving a large volume of requests from your network. This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. Yes, well, we have to put 67 feet of wire somewhere, so let's extend the wire by pulling more wire out of the chalk line reel and over the top of the pole, make a shape that is really easy to deploy, resembling a shark fin, just be sure that the far end is up at least 3 to 4 feet up off the ground. How to Make a Balun or Unun: I needed a simple portable HF antenna. 5MHz) therefore also resonant on second, third and fourth harmonics etc. Simply put: electrical service ground is NOT a substitute for a good RF Earth ground, which is required for a good antenna system. These ideas from G3WQW appeared in Sprat 95. End Fed EFHW-4010-1K 40M-10M wire antenna More Buying Choices $173. To make sense of the SWR analysis, you need to set the characteristic impedance of the system to 3000 ohms as this is roughly what the matching transformer will map to. 89 Until 10/31/19: ICOM IC7610 HF SDR $2968. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. What they really offer is delivery confirmation only. The formula has no relationship to the design, other than being a reference point for a 1/4 wave element. I had some struggles with this matchbox due to excess stray capacitance as well as using some low quality binding posts for the ground and antenna connections that caused some intermittent connections. Lower elevation means poorer results on 80, 40, 30 and 20 meters. EFHW-8010 8-band End Fed Half Wave antenna product reviews by real people like you. I may hang not just the center, but also the far end of the wire as high as possible to lower ground losses. Fortunately, EMP protection has been studied by Dennis Bodson, W4PWF, and effective mitigation. Both radiate just the same amount of r. I’d also take a pair of solder-less alligator clips (less than $1 each, many sources) and a solder-less 3. And, the impedance and reactance are perfect! Below is a quarter wave ground plane antenna I made for 23cm, 1296MHz which is made from off-cuts of household mains copper wire and a scrap BNC socket from the junk box. K2YWE's Compact 160m Lazy-U Antenna This compact 160m antenna is a half-wave dipole with a vertical section. 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. Driving through the picnic ground, I … Continue reading →. The first thing. 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 […]. In that case, expected efficiency (meaning PowerOut/PowerIn) of the transformer was less than 65% at 3. SDRplay have recently posted a new workflow document and video that shows how to easily set up GNU Radio on Windows with an SDRplay software defined radio. " I think you might want a counterpoise for use on the WARC bands. I do recommend a good common mode choke balun within maybe 5 and 20ft of the antenna. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. The current horizontal EFHW is up about 35 feet in a tree. There was an issue with the ISS VHF downlink during this pass, so the contact was rescheduled to the next pass, at 2015 UTC. 73, Vojtech OK1IAK, AB2ZA. EFHW End Fed Halfwave Antenna is a curation of 25 resources about , 20m Half-Wave End Fed, The EFHW Antenna, End Fed Half-Wave Antennas, EFHW matching unit, End Fed Half Wave Antenna Coupler. html https://www. 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". Bil, KD6JUI recently wrote to me asking about a design for a tuner capable of handling 30 W, but, presumably, is not as big and heavy as a 100 W tuner: I read online that you had been working with matching devices for end-fed, half-wave (EFHW) antennas. As typically installed, it is a compromise antenna but great for portable use because it is easy to pack and easy to install. 5MHz) therefore also resonant on second, third and fourth harmonics etc. I've also now tried it with my 40m-15m trapped EFHW and it seems to provide an acceptable SWR for all 5 bands. This is an End-Fed Half-Wave (EFHW ) antenna for 80/40/30/20/17/15/12 and 10m bands. Method Two SOTA aerials were set up in an urban surrounding in IO91ij. In spite of what some manufacturers will tell you, an end-fed 1/2 wave ALWAYS has a counterpoise. The ground plane depends on your soil, in wet mud a simple ground pin will probably do the job. I purposely didn't install a Common-mode choke on the coax from the EFHW, nor did I connect an explicit ground to the coax. Build an op amp with three discrete transistors. Given the 1/2 wave EFHW, would a wire to a ground stake help significantly and does the length of that wire matter?. Simply hang the far end from a tree limb-the coax is at the bottom. con esto he conseguido una antena para 4 bandas con un lóbulo de radiación mejorado para DX con respecto a la EFHW horizontal que también tengo instalada, tambien mejora a la. Grounding the EFHW Antenna. ' The idea is this: If one end of the rope accidentally gets loose, it will jam when the knot reaches the pulley. A "portal" that hams think of as the first place to go for information, to exchange ideas, and be part of what's happening with ham radio on the Internet. Untuk itulah diperlukan counterpoise & choke balun. The missmatch loss between 50 and 75 ohm is something like 0. Ground Rods… so easy a pre-teen can do it. PAR/LNR EFHW antenna. Dipole • Ground and radials required • Remote tuner required. 35 when clearly the formula outcome is 1. While the feedpoint resistance of the EFHW is quite high, the radiation resistanc e is approximately the same as a half wave dipole, 73 ohms (the EFHW is essentially a half wave dipole fed at the end instead of the center). 80M is actually a bit lower and 40M and 17M are just about as perfect as well. Some people swear by endfed halfwaves, while others swear at them. The EFHW can effectively be deployed like an inverted V which means a 40m EFHW can work with a 6 -10m telescopic fishing pole. I've settled on a EFHW-8010P from myantennas. I may hang not just the center, but also the far end of the wire as high as possible to lower ground losses. I’m being particularly unfair to the loop as it’s less than 2m from the 2 floor house and metal fence+shed, a foot off the ground and wedged in a bush… It still performs reasonably well, and definitely shows directivity. 18 thoughts on “ NVIS Antennas ” Leonard Hunsicker on August 26, 2019 at 3:06 PM said: I have been using a 1/2 wave 75 meter Inv- Vee up abt 17 feet directly above a couple mile long 4-wire barbed wire fence. Post # 144 MHz 4 element yagi - dimensions. Hang it up in a hotel window or string it up in. How to Install Ham Antenna Ground Radials. There is a popular myth among Hams and technical writers that USA Standard Broadcast systems require 120 radials. I soldered together two small pieces of tinned G10 double-sided circuit board together and constructed the SWR bridge and associated switch using classical "ugly style" construction. It's assembled onto a homebrew wire winder. If you are using a tuner that has just one wire coming out of it, then the other half is the tuner's chassis, and whatever is connected to it. I understand that it's needed, but I don't understand what the requirements are. I had flashbacks of digging this hole at the place in Wylie and I was nervous about it this go around. Question on grounding EFHW (self. To make sense of the SWR analysis, you need to set the characteristic impedance of the system to 3000 ohms as this is roughly what the matching transformer will map to. EFHW End Fed Halfwave Antenna is a curation of 25 resources about , 20m Half-Wave End Fed, The EFHW Antenna, End Fed Half-Wave Antennas, EFHW matching unit, End Fed Half Wave Antenna Coupler. EFHW-40S-1K End Fed Half Wave Antenna-NO TUNER NEEDED! EFHW-40S-1K Single band End Fed Half Wave Antenna. Find many great new & used options and get the best deals for HF End Fed Antenna EFHW-8010-2K 2000W 80-10m / NO TUNER NEEDED!! / 130 feet long at the best online prices at eBay!. A DC ground is desirable for lighting and static electricity, but not required if your counterpoise wire(s) is effective. I have one of the original PAR end fed half wave antennas prior to LNR taking over production and sales. I had a BN43-202 core in stock and attempted to try to create a small QRP EFHW transformer from 7 - 29 MHz. Second, the high current part of the wire, which does most of the radiating, is a quarter wave from the feedpoint, which can usually be much higher than the feedpoint. This is an End-Fed Half-Wave (EFHW ) antenna for 40/20/15/10m bands. QRPGuys Portable No Tune End Fed Half Wave Antenna - $20 We continue our antenna offerings with this single band, 80m-10m end fed half wave wire antenna. net provides recognition and enjoyment to the people who use, contribute, and build the site. A rotary-dial switch, seen in the photo below, right, selects the secondary taps. Top is about 15-20 feet above ground. The attached pictures show the setup. This might not be the best antenna, but for my circumstance it is up and working. great antenna going to pick up the EFHW-4010 next for the other side of the house. 91kg including the squid pole).