40m doublet

40m doublet. HOA HF Vertical. Half Delta Loop Antenna. After playing with various designs and ideas, I decided to build a base loaded vertical antenna with 2 radials for use on all the bands from 6 to 40 meters. Kelemen Dipoles are rugged; strong but lightweight, with good stability and excellent longevity. This makes it pretty much bomb-proof. I quickly matched the doublet using the BLT+ using the lowest impedance setting which is also the most Jun 2, 2022 · The 44 foot doublet revisited. 1. Grab some speaker wire, scrap coax, pvc and a toroid and make a trapped dipole. Feb 19, 2019 · That means that a 160 meter loop cut for ~1. Apr 12, 2024 · 33W into a mobile whip in the garden on 12m now. For SOTA I made myself a 40m doublet, fed with 300 ohm line, using a lightweight BLT Tuner. Nov 28, 2023 · The Bow Tie Loop was designed to provide dual-band operation on 160m/80m, and the performance on 40m is often adequate. Then we will feed it with about 11 m (36 ft) of 300 ohm twinlead to a tuner, so the radio sees 50 ohms, as shown in Figure 2. Apr 29, 2013 · A limited space 40 meter dipole. Please provide us with more detail. On 40m it becomes a center fed full wave dipole so the impedence in the center is quite high but despite that, the tuner seems to cope with it. 7K subscribers. This creates an inverted V configuration. Cebik W4RNL (SK) popularized the 44-foot doublet for 40M-10M. Have worked all over Europe/Russia with it while portable from the northeastern US. The new 80M doublet with 600 ohm ladder line is performing a bit better, a little quieter than my Hustler 6BTV vertical, and compared to the 40M dipole seems to be less affected by weather. All-Band OCFD. In fact, most novice hams since the 1920's have started this same way. In this video I will show a DIY 40m Doublet that is perfect for SOTA/POTA with Radios with internal tuners capable of 10:1 Mar 20, 2020 · In simplest terms, it’s a 40M doublet made from #26 copper-clad stealth wire. Carolina Windom. However having 1. Kelemen Double-Band 80M & 40M Dipoles are high-quality, preassembled wire antennas featuring full-size elements for both 80 and 40 meters, 128 ft. The purpose of this project is to design a simple multiband vertical dipole antenna for 20 meters and above, with a tuner, that will provide gain and a circular pattern on the higher bands. More designs can be found by Googling “80m loaded dipole. Only reason I don’t always opt for it is the need for 3 support points. Mar 25, 2016 · I used the BLT+ to tune the 40m/80m doublet. Lower frequencies will pass the trap effectively making the antenna bigger. Off-Center-Fed Full-Wave Doublet Antenna. Mar 11, 2019 · 1. I've used a ZS6BKW as a simple "second" antenna at my shack for a while. For the PAL8010OCF, the impedance is very well behaved in a limited, easy to match range throughout the 1-54 MHz range and, in fact, that antenna also works very May 7, 2020 · Thanks to Andy Wragg for this simple, effective NVIS (near incident skywave) antenna for 40 and 80 meters. However, electrically, it is significantly different. 51. But later on, he wrote about a 44 foot doublet for 40-10 meters: Dec 17, 2023 · A 40m version would then be useable on 20, 15 and 10m. HF Military. 13. The size of the vertical element is 2 meters, so it will comfortably fit under the ceiling in the room. The best advice I've seen for tuning in doublets is to keep its length as far away from resonance multiples on as many bands as possible. When I put this one up, I was rather astonished at the improvement over the doublet - on the order of 15-20 db! Apr 10, 2020 · Learn what you need, best practices for unspooling wire off a reel without getting it twisted, how to put the doublet together from start to finish (including preferred knots), winding it up for easy transport and installation on a SOTABeams Tactical 7000hds Compact Heavy-Duty Telescopic Mast, and use of an antenna tuner and balancing system to Jan 20, 2022 · My previous Linear Loaded shortened dipole for 40 metres works well but is mono-band for 40 only. It is a simple linear loaded dipole feeded with 450-Ohm openwire feedline . Space Saving Ant. Let’s consider another example: a 40m doublet that is 26 m (85 ft) long. NVIS antennas provide excellent local, state, and regional coverage at a modest cost. Worked 40m / 20m / 15m. Fig. The Sloper. I've worked on multiple random length doublets. If you are right on space but have a tall tree you could try out a quarter-wave 80m vertical (~20. Schematic layout of the center-fed Zepp. 160M End-Fed. Sales/Support: 760-747-3343. My favourite antenna is a 40m doublet fed with 300 ohm line and I use 24 gauge insulated stranded wire and small plastic homemade insulators and wire winders. 14 to 15. We used the generator to power the FT1000MP MkV (200w) effortlessly pumping the hydraulic mast up to 10m with the SG230 bungee-strapped to the top, running one of our 80m dipoles across the top to form a 1. Sep 5, 2014 · Shortened, loaded dipole. Fanned dipoles 4. Like the big multi-band dipole, the big multi-band loop works best at about 68 feet high, where it’s a half-wave high on 40 meters (but it’s still okay at 30-45 feet), and ladder line feed. I’ve since been able to buy a stash of 15mm wide clear acrylic pieces in 50mm, 100mm, 150mm and 200mm lengths which make May 12, 2015 · I’ve used the NorCal Doublet (computer ribbon cable). (Of course, it can also be built for 80m/40m. We would like to show you a description here but the site won’t allow us. Why not try this idea? A short doublet for 40m and above. G7FEK’s original “Nested Marconi Antenna” was first designed in 1988 and comprised two quarter-waves in parallel, fed against ground in inverted L. Feb 28, 2016 · A 40m doublet can offer significant directional gain especially when operated on higher bands. B. The loop is just 1m above ground level and the doublet is fed 8m AGL and is in an i Dec 21, 2020 · Great to get on the air and many hams have done the same for decades with a basic doublet. Mar 10, 2020 · Many folks suggest making the doublet a half-wavelength long at the lowest band you intend to use. Bill takes you step-by-step through the entire design, building, and testing process. The second harmonic doesn’t work great because the full 1-wavelength wire cancels its own radiation; while current is going “left” on one half of the antenna it will be going “right” on the other half. Figure 1. Double Doublet. It essentially is a doublet (dipole) wire flatop antenna fed with real 600 ohm open wire feeders. The broadside doublet(s) 3. The spreaders can be made from any non-conductive material such as PVC conduit pipe or you can use ladder-line and make the whole lot from 1 piece of cable. SWL Active Loop. 40m doublet on 20m • Zin = 1717 – j2505 Ω SWR50 = 107:1 – ‘L-network’ can match – but the components must be swapped around from 80m configuration • 16 feet away through the feedline: – Z in = 29. Post 2153. The Multi-Z tuner is based on a design by Charlie Lofgren, W6JJZ. A great way to get maximum performance from one antenna over many bands. Build a space efficient trapped dipole antenna for 40-80-160 meter bands using RG-58 and PVC pipe by W8NX. The antenna system should also be useful for other HF services i Ladder Line Fed Antennas - Palomar Engineers®. Another popular doublet/zepp. 4) Doublet, dipole…. The dimensions of this aerial were specifically for my old QTH but you can adjust it to suit your circumstances. Post Magnetic Loop Antennas. Portable shack, courtesy of three plastic chairs. included). Post 2154. Good lengths are green shaded area in the chart below. Balanced line antennas perform better with a tuner designed for balanced line and this was a good test for both the tuner and the new antenna. I designed it for resonance at 7. It works very well and can bundle up to fit in your pocket. Tuner adjustments are monitored in an SWR bridge or directional watt-meter (not shown). Post 2157. 9 Ω – L-network needs original configuration L-network configuration depends on the line length Feb 19, 2024 · YJ0VK Update (Mar 29)FT8 been running for 24 hours. 40m doublet up and we'll be on SSB and CW as well this evening. Sep 14, 2022 · The dipole-doublet(s) 2. It is all very lightweight, not bulky and efficient. Double Extended Zepp Antenna. Here are some typical OCF dipoles that are successful designs 160-6 meter Double Off Center Fed antenna layout (using a double tuned stub for better 20/40 meter performance) Here is the 160-6 meter SWR graph using 200 feet of RG213 feed line and an average height above ground of 35 feet: Palomar Engineers PAL-OCF1606 […] 102 ft. I have another doublet with an older COMEX 4:1 balun and have had no problems. I plan to build a Norcal doublet soon, and might try one very similar to this WD8RIF 40M doublet. The diameter was determined by available aluminum tubing. The broadside doublet(s) 2. Indoor antenna de F6CYV. For example, a 40 and 20 metre trapped dipole would have traps installed at the 20 metre points which would prevent the 14Mhz band, effectively shortening the antenna. This antenna generally requires the use of a suitable matching network (antenna tuner) since the SWR of the G5RV JR is ALL BAND DIPOLE Mk2. 6m). The dipole-doublet(s) 3. 6. For the latest Amateur/Ham Radio news and information When making a short dipole, one has to accept a set of compromises. Had trouble getting it to tune on 20m some years, depending on the exact length of the ladder line. Take the computer cable, and strip the outer two conductors down 22 feet, leaving the two middle wires connected together. Post 2158. 2. Handles 1. 9 and a loss of 0. According to Cebik’s analysis, this length Dual-band dipole elements. It’ll tune up on basically anything you want above 40m. 59. 4. The feedline must be affixed to the antenna more se-curely than the drawing shows. 160m Linear Loaded Sloper Antenna. The doublet has several good features: it will cover a AsshowninFigure1,thebasicall-banddoubletantennasystemconsistsof3parts: the antennaproper,thefeedline,andtheantennatuningunit(ortransmatch). 80-10 meter OCF antenna layout. Details in comments. These can also be built from kits, or purchased. 10m coverage (and 80m for that matter) is a bit poor. The feedpoint impedance is about 200 + j490 ohms, so clearly not resonant. I quickly matched the doublet using the BLT+ using the lowest impedance setting which is also the most Kelemen Double-Band 80M & 40M Dipoles. Ladder Line Fed Antennas. No wonder then that LB Cebik, W4RNL picked the doublet as one of his top five multi-band backyard antennas [Cebik, 2009]. Many hams don’t have room for a full 160m dipole, so I started designing coil-loaded antennas, and discovered it was relatively easy to make a single element work on both 40m and 160m, with a length roughly that of an 80m INTRODUCTION. -----. Co The wire-length on this 40m version is actually about 12m per leg. 57MHz in the CW portion and the SWR in the 3. Very slightly better than a dipole on 20m, similar on 40m and 15m. Trapped dipole for 40-80-160 meters. I’ve built one for 40M and it worked well on 40M and higher. 3. To avoid problems matching or feeding any dipole antenna with high impedance lines, keep the lines around the length in the green area of the chart below. I use to simulate all my antennas with MMANA-GAL. NVIS dipole. Antenna Calculator. A design by VK3JEG is only 66-ft. This new 40m doublet and the feed line are the correct lengths and orientation to avoid problems. An 80m version is a bit different as 75m phone is not harmonically related to any other band so to get it to work on 40, 20, 15 and 10m the 80m resonant point will be down around 3. Redid my "stealth" apartment doublet. 9 MHz Full-Wave Loop Antenna. Sep 29, 2022 · Building a short 40m antenna with coil and AT-271 Home made vertical portable antenna; Experimenting with a Loop On The Ground Receiving 5/8 Wave 10m Vertical Antenna Build; Build a Portable 10 Meter Yagi Antenna; Small, light Antenna Spike for HOA, POTA, SOTA por Simple Stealth Ham Radio Antenna for HOA Hams; Off Center Fed Dipole Actually, this is an antenna that goes way back to the simpler days of ham radio. Dec 20, 2020 · Great to get on the air and many hams have done the same for decades with a basic doublet. The Broadside Doublet(s): The broadside doublet is a simple multi-band doublet with a 4:1 frequency range for the desired characteristic. I don't mean to imply that the ladder line doublet is the perfect antenna. 1m of 300 Ohm twin-feeder. 40m doublet example. The original design shows two wires of 14. B. Cebik, W4RML (SK) wrote a detailed article on doublets: For a 40-10 meter doublet, he recommended a length of 67 feet, or a half-wave on 40. 5) Any centre fed aerial working away from it’s resonant frequency. Attic SWL Antenna. Wire Antennas. NVIS antennas are great for rag chew nets or for emergency communications in your area. 10m -160m Multiband “Z” Antenna. The benefit of this antenna over my existing 44' doublet fed with military 72Ω twinlead is that this antenna is made of continuous lengths of wire with no solder-joints to fail. 600 ohm ladder line length adjustment and tuning; 100 watt 7 MHz magnetic loop antenna for units and A timber antenna mast. Tunes up nicely on 6-40m with the KX3. Dec 16, 2022 · Or maybe just a better tuner?Click the 👍 Like Button, 🤡 Leave a Comment, ️ Subscribe👉 Support The Channel 👈 ️ Patreon: https://www. The MFJ-1778M consists of 52 feet flat-top fed with 17 feet of 450 ohm matching section ending in an SO-239 coaxial connector. Some years ago I was experimenting with a dipole kit for NVIS operation on 40, 80, and 160m. 5. N4LQ 160-10 Multiband Doublet with Auto-Tuner. 78 MHz (1005 ÷ 1. 6 ft. Top Five Get-On-The-Air-Quickly Ham Radio Antennas Ham Radio HF Antenna For Limited Space, Post #1546. Verticals are great due to low takeoff angle even on lower HF bands. If you’re going to get a tuner, look at a ladder line fed doublet for 40m. Now it’s a dipole on 80 meters and a doublet on the rest of the bands. 160M Windom. A multiband 80-40-20-15 meters dipole wire antenna that can be extended to cover 160 meters too. Of course the impedence seen by the tuner depends on the length of the feedline. Let's model a G5RV in EZNEC and look at the feedpoint impedances. HF Vertical. 78 = 564 feet) will be current-fed also on 80, 40, 20, and 10. The second is to get the center of the antenna up as high as you can and pull the ends out as far as you can get them. Mar 31, 2023 · I used the antenna for 2 or 3 years, until I had an injured foot and couldn’t scramble up and down the slope to install it, so I put up a quick 40m doublet instead. The half-wave length dipole fed with 450-ohm feedline (the classic "doublet") is a basic antenna that will give you hours of enjoyment and plenty of DX if the flat top is at least 30 to 50 feet (9. patreon. This balanced feedline is low loss in design and allows the antenna to work all bands if you utilize a real balanced matching network. 2 metres fed with 11. This, supposedly, 1500 watt Palomar balun saturates and heats at even 200 watts using the FT-8 duty cycle and it saturates as fast with SSB. Mar 29, 2024 · This works quite well, used as a multi-band doublet. 40m - 80m - 160m Short Dipole Antenna. 160m Half-Sloper Antenna. A full-wavelength doublet also presents a very high impedance feedpoint in the center of the span and it’s quite difficult for a Here is my dipole for 40m band. Since virtually all of the antennas will be horizontal, the logical baseline to use for comparisons is the near all, HF bands: the multiban d tuned doublet an-tenna—or, as it is often called, the center-fed Zepp (Note 1). Not quite as good as the big loop, but easier to install. 160 meter dipole. Some lengths are harder for antenna tuners to dial in that others. 80m Cobra Doublet. Product Manuals. 3) An aerial where the balanced line is exactly the same length as one leg of the dipole. Jul 20, 2018 · Homebrew 10/20/40m EFHW vertical antenna-"SOTA", P Building a Doublet Aerial. Download Product Manual. Title. The exact length depends on whether you want to focus on 40M CW (33 feet) or the upper end of the band for SSB (30-31 feet). The key to the antenna's multiband capability is the use of a balanced feed line and an "auto-tuner" (MFJ-998). I frequently operate SOTA on 40m CW. The addition of an antenna "tuner" will help you keep SWR as low as possible. A good, reliable 40 meter antenna made from materials you may already have. ) An 80m doublet will have added overhead gain on 40m, but a the pattern of a 160m doublet has an overhead null on 40m unless the wires are bent. It does work and gives some multiple band benefit as your presentation shows. 10M Antenna. The MFJ-1778M antenna is a multi-band center-fed dipole antenna capable of 1500 Watts. Original review: When I set up the seaside QTH in PEI, I worked many EU stations using Optibeam antennas with my 40M doublet. The exact length is not critical! If you don't have room for the 160 or 80 meter versionthen design it for 40 meters and up! Aug 23, 2015 · Addendum (9-18-2015): The Attic 40m Doublet actually outperforms my 40m Carolina Windom to the West (both receive and transmit) It's about 12db down on receive compared to the Windom to the North and South even though it equals it in transmit performance (according to a few reports where I've asked for A/B comparisons). The bandwidth limitations on 160 and 80 meters can be largely offset with an antenna tuner. Even at lower elevations, this simple, inexpensive antenna will provide strong Feb 10, 2023 · 40m doublet fed with ladder line. We will assume the dipole is built with #14 bare copper wire at a height of 30ft over average ground, and that the matching section is 300 ohm ladderline with a velocity factor of 0. Overall it works better, but having more RFI (or common mode) issues on 40m. It can be designed for use from 160 thru 10 meters very easily using the standard 1/2 wave dipole formula: 468/freqmhz = total length (ft) end to end. Two more antennas go up tomorrow. The hohpl--horizontally oriented and polarized loop 5. 40m doublet up and will be on SSB and CW as well this evening (local time). Authentic glazed ceramic end insulators. There’s no difference. Feb 9, 2007 · The good thing about this particular multi-band antenna is that it covers the majority of the HF amateur bands that I'm interested in, particularly 80m, 40m, 17m and 12m, as well as 20m. vertical antenna projects for the 40 meters band category is a curation of 44 web resources on , Vertical antenna for 40 and 80m, Slink-ette antenna, The Hudson antenna. This is the standard configuration. Post #1548. Post #1543. 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. Replaced by dipoles and coax feed, which eliminated the tuner. Magnetic Loop Great HF Apartment Antenna. Small Mag Loop. and 65. Jul 5, 2018 · A nicely designed and built 160-10 meter doublet antenna from Steve Ellington (N4LQ). The original antenna was roughly 50 feet long x 22 feet high. The exact length is not critical! If you don't have room for the 160 or 80 meter versionthen design it for 40 meters and up! Nov 7, 2021 · Doublet-take! It’s time to put a few doublets in my antenna arsenal. M0XXT/P HF Doublet Test. respectively. It'll easily tune 40-10m and works very well. Another option is a shortened dipole using loading coils. 326. You could also double those lengths, resulting in 67 foot vertical and horizontal elements. 33W into a mobile whip in the garden. After soldering wires to an SO-239 socket and routing the wires through the end cap, the inside of the end cap is potted with epoxy. James and I tested out a doublet today in preparation of our trip to Hampton in Arden Cubs, Friday 30th November. 10m. The QRPGuys Multi-Tuner is a Z-match design that will match a wide range of coax fed, long wire, and balanced line antennas, like high-impedance, low-loss UHF twinlead or ladder line for 40m-10m. Trapped dipole 20 & 40metres. Design Software. The Antenna Feb 11, 2019 · C ebik (W4RNL, SK) described a “doublet” as as a dipole that is fed with ladder-line and operated on several bands. The latter with poor results. Cut the two middle wires off about 2" above the 22 foot mark where you stopped stripping the outer connectors. . Subscribed. 2) Any aerial fed in the centre with balanced line. I use it with a 4:1 balun. 2dB/100ft at 30 MHz. The lengths of ladder line to avoid also depend on the length of the doublet you are feeding and the frequencies you intend to transmit on. 3 shows the general outline. Resources listed under 7 MHz Vertical Antenna plans category belongs to 40M main collection, and get reviewed and rated by amateur radio operators. Or simplify and put the funds toward a qrp antenna tuner and fab up a doublet. I noticed that the antenna is cut a bit short on 80 and 40, no more than 3:1 VSWR to band edges with resonance at the high end of the band. Antenna (RF) Calculator: Radio and RF units conversion/JavaScript applications. Dec 6, 2015 · We would like to show you a description here but the site won’t allow us. At later sites the forest was too dense to put up the loop, so I used the doublet, or a set of dipoles. 050 MHz, but using my LDG AT 100-PRO-II tuner I can tune it also on 30m and 80m bands. Here are some typical ladder line fed antennas: Fine Ladder Line Baluns HERE. 5 kW. long, about the size of a 40m dipole. This means your RF has a better chance at traveling farther to get DX, of contacts with folks in other countries. This article lists the main ones and how to minimize their negative impacts. all band doublet covers 160-6 Meters with balanced line tuner. Building A Multi-Band HF Dipole An EFHW with a 40m half Wave element will be resonant on 40m, 20m, 15m and others. In principle, the doublet is physically no different from a dipole. Homebrew 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. 5-70. On 12m now. 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. Feb 17, 2011 · The first is to get each end up as high in the air as you can so that the antenna is a straight line (it’ll droop a bit in the middle). With a 1064m2 (1/4 acre) town block with a depth of 60mtr (200') I intended to improve on my previous All Band HF Doublet with an antenna that would be suitable for all the HF amateur bands, including the so called WARC bands and including the 160 metre band. Feb 2, 2021 · Compare my homebrew Magnetic Loop for 40m band to a tuned doublet aerial. Terminated Sloper Antenna. Does it make a difference that the antenna isn Portable Doublet. Po Ham Nation 355: All About Fractal Antennas. 35-60, 170-195 or 210-235 feet. Most really good balanced tuners will take care of the problem, as long as the doublet is at least 1/2 wavelength long at the frequency of interest. It will supplement the big horizontal dipole by providing good omnidirectional coverage, with some gain, from 20 through 6 meters. 8 to 4MHz range will be high. ”. com This is the price paid for multiband coverage and physical short- ening. The general design formula for this type of antenna is quite simple: A wire dipole, center-fed, length (feet) ≥468 May 23, 2020 · Thanks to Bill (WX4AR) for this concise, accurate, and simple way to build a "classic" double bazooka antenna. Stock availability and shipping volume can delay shipping. This antenna covers 65 kHz of 160 meters, 75 kHz of 80 meters and the entire 40-meter band with SWRs under 2:1. 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. For the PAL-OCF8010 with 250 feet of RG213 feed line and an average height of 30 feet: Palomar Engineers PAL-OCF8010 Antenna manual 05242021 29. Basically, the loading coil is operating as a trap. Feb 18, 2020 · Five minute portable 40m Ground Plane Antenna. 24 meters) above ground. Ed used a 3/4-inch PVC end cap for the center insulator (see photo). You can run coax into the shack and put a 4:1 balun to the ladder line outside. Loop the 2" piece of double strands over the eye of the fishing swivel. Short Antennas "Loaded" Dipole. 12K views 3 years ago #MNHR. Pos The Flying Antenna. 5 – j2. The inverted-L In order to make sense of what we say about each type of antenna, we need a point of reference. During 2007 the antenna was optimised and tested at sunspot minimum to improve performance and multi-band operation. They were invariably louder than any stations other than mono-banders. Another design by KB0ZZ is a little longer, but resonates on both 40m and 80m. Feb 12, 2022 · Subject: Re: 44 foot Doublet Antenna Sun Feb 13, 2022 12:39 pm. Now unless it's rotatable you will be at the mercy of the directionality of its lobes but if you have trees or tall structures you can very cheaply string up a few dipoles oriented in different directions and for far less money that a 500 watt amp (6 dB). What I really liked about Eric’s doublet is the fact that, not being terribly high at its center point, it had NVIS qualities. L. In total, it had around 18m of wire per leg folded 3 times and fed Mar 25, 2016 · I used the BLT+ to tune the 40m/80m doublet. Making open wire feed line. For the PAL8010OCF, the impedance is very well behaved in a limited, easy to match range throughout the 1-54 MHz range and, in fact, that antenna also works very 4. Suggested lengths for high impedance feedline on dipole type antennas. So “multi-band ladder-line-fed doublet” is redundant, but I used it in the tag-line for search purposes. A DOUBLET IS: 1) A centre fed aerial which is too short on the operating frequency. The inverted-L If he had only one antenna that covers 40M-10M with known direction: The 44 foot doublet 8 G3RWF Doublet –40m antenna wire only 18m apex & slopes to 15m – base line of dipole impedances 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. SWL Antenna. Homemade Ant . Doublet antennas have been used for decades. VK5AH -HF 4 Bander dipole. Super strong custom fiberglass center insulator provides stress relief for ladder line (100 ft. Tunes 40-6m using a small lightweight BLT tuner. Depending on your tuner, it may also be usable on the next lower band. hx ev tv rw zw rv kf nz kq vp