Others Hams with the Rhombic ARRAY

K0UO 100 foot Rhombic poles and wires. K0UO is one of the last stations in the world using Rhombic Arrays, since they were designed and engineered for 40 meters they are larger than most ham antennas.

Historic Preservation: The K0UO station actively preserves and utilizes parts and insulators from legendary, historic radio arrays, including those from W6AM (Don Wallace), W7YRV Roy, BBC, Voice of America (VOA) and many others.

So symbolically those large Nostalgic historic stations are still, "On the Air Daily" by K0UO, using an extensive array of towers and antennas, now the largest HF ham arrays still in use today.

W6AM

In the 1950s to 1970s W6AM had many 1000 footers, and one was 1500ft. In fact K0UO is still using some of W6AM's hardware on his antennas, a living memory to W6AM, On the Air Daily.

The old W6AM site layout map

Roy W7YRV/SK had nine at one time, and he developed the X Rhombic, which he had built one for every 20 degrees, (18 total). That was a truly remarkable accomplishment for an amateur station (You must see his page, great info w7yrv.blogspot.com/2013/).  It was an extreme pleasure for K0UO to meet Roy, even in his 90's, he was still an encyclopedia of knowledge when it comes to very high gain antennas. K0UO is very privileged that W7YRV has entrusted him with the parts, schematics, drawing, and photos of these fabulous antennas. https://w7yrv.blogspot.com/2013/10/other-antennas-stuff.html

W1VDE Roger in OR has six and is on the air daily, also VK3MO, and in Texas N5APR and W5BY Jeff, had a few at their ranch's, W2DGU Rich in NJ, KL7KK in AK has one along with a few VK's, and V55V (V55W) in Namibia had 2 but they are now down, and TF4M also put up a large HF one at one time.

The Old V55W station in Namibia was about the same size as my Rhombics but not as high.

Martin Walter, V51W, near Omaruru, Namibia, has spent the past 2 decades improving his station, which likely accounts for his V55V station’s increasingly better signal.

After trying all possible antenna systems, he is convinced that his wire rhombic antennas are the best choice. He uses three of them; two that are 160 meters on each leg to the US and Europe, and one with 80-meter legs, also aimed at Europe. Their gain depends on the band and can top 10 dB.

V55V was used for countless contest and DXpedition activities during the past years, but now, Walter has shut down the station and move back to Germany.

https://mail.google.com/mail/u/0/#inbox?projector=1

W0TEC Jack Herndon had one up in Kansas for VHF and over the air TV, in the 1950-1980s, K0UO is still using parts from that site also.

VK3MO Ian sent K0UO this overview in Aug. of 2025, "My single rhombic is still in the air and functional. My rhombic is supported on 4 X 132ft steel towers guyed with non metallic guys. The rhombics are stacked with one at 70ft and the other at 132ft. There is 550ft per leg giving a total radiating wire length of 4400ft.  My original objective was to build an antenna for 20M with gain. It obviously works well on the other bands.  I run open wire feeders from each end of the rhombic back to the centre where I have a large TCI balun and a tuner. I then have a 600ft run of LDF-450 Heliax back to the shack. (it is a shame to lose a dB on the feedline).

I use 2.84mm diameter hard drawn copper wire for the antenna and feedline. It has survived thirty years without breakages. I started out using stranded copperweld wire and it failed after two years. It developed rust bubbles and started breaking regularly. I pulled it down and started again with the hard drawn copper and not a single problem in thirty years. (I suspect the stranded copperweld wire may have been poor quality. I purchased it from the wireman and the results were disappointing. My rhombic is aimed at New York". 73

VK3MO His rhombic has a gain of 23dBi at a take off angle of 5 degrees on 20M and is directed at New York. The rhombic was modeled using EZNEC and it has 3dB more gain than the 5/5/5/5 yagis Both the yagis and the rhombic have a take off angle of 5 degrees which allows a comparison between the two antennas in the direction of New York. Ian sees see the 3 dB advantage which validates the accuracy on NEC antenna modelling software.

ZL6QH, the Quartz Hill User Group station based near Wellington, New Zealand, is no longer in active operation. The station ceased its original HF DX/contesting activities in 2007, and the Quartz Hill User Group was formally disestablished in 2016, K0UO has a few parts in use for that site also. The QHUG committee had been planning a new remote HF DX/contesting site to replace Quartz Hill, but after 11 years of inactivity, they decided to wind down the original station. Resources were redirected toward the RemoteDX Inc. project, which focuses on establishing and operating remote HF DX and contesting sites across the Wellington region, but not Quartz Hill. 

W6OBB Art Bell

Art said: "The big loop antenna was held up by a total of 13 steel pole towers, and those towers are about 76 feet tall each. Again, each one's supporting this double loop, and it's an amazing antenna. I don't know what to tell you. It's simply amazing. It'll make a hundred watts sound like several thousand. It's that effective, and I put it up mainly for 160, 80, and 40. I really, really love 160 meters.

THE ARRL W1AW Diamond Rhombic ANTENNA LAYOUT 1937, FROM QST

W1AW utilized a single Rhombic antenna directed west from Connecticut until the 1980s, when it was replaced with a stack of beams. However, as noted in QST, "They never had the North American signal that they had with the Rhombic." The W1AW Rhombic outperformed the beams, and there are old maps illustrating the coverage field strength of the Rhombic. Despite being a short Rhombic, it provided a strong U.S. signal even on 80 and 40 meters. The coverage map and signal pattern diagram of the old ARRL W1AW Diamond Rhombic antenna (as it was called) originally appeared in QST Magazine around the time the historic West Hartford, Connecticut memorial station was established in the late 1930s. The station began transmissions using the W1AW callsign in 1937, and the classic layout maps were featured in 1937–1938 QST articles. Map Details & Characteristics

• The Concept: The sketch features a classic North American map overlay illustrating the reception and field strength patterns of the W1AW diamond rhombic antenna as it fired west from Connecticut.

• The Data: It showcases indicated signal gains and relative line-of-sight losses across different states and U.S. regions, measured directly using a vintage National Company HRO receiver.

• The Pattern: It provides a general overview of the antenna's directivity—demonstrating how transmission conditions and a station's precise geographic location relative to the major forward lobe or minor sidelobes affected the received signal strength on the 40 and 80-meter bands.

• This was a small lower mounted rhombic: It was used on 80 and 40 meters with excellent results form the 1930s to the 1980s, QST field maps documented a legendary domestic signal that many operators noted was never fully replicated by modern directional Yagis.

While W1AW eventually replaced the small but multi-acre wire Rhombic array with a stack of aluminum beam towers in the 1980s, these original 1930s QST field maps documented a legendary domestic signal that many operators noted was never fully replicated by modern directional Yagis. You can view or reference this exact historical diagram layout directly via your active Hams with Rhombic Blog draft under the section detailing the vintage ARRL antenna layout.

The K0UO site uses repurposed equipment from W6AM's old station, W7YRV, Voice of America, The BBC and other legendary stations.

Steve Walz K0UO utilized the former Voice of America (VOA) site in Belize as his antenna farm for V31KW. Steve sayd: "It was by far, the best large legacy HF site that I ever used" it had Rhombics and Curtains arrays. Rank and Being a Broadcast Engineer has its perks, and I've had the opportunity to visit numerous fascinating RF sites over the years also.

From a technical and raw performance standpoint, it is the most powerful, unique, and highest-gain HF wire antenna farm still in existence anywhere in the world. While systems like RemoteHamRadio (RHR) rely on standard towers and stacked aluminum Yagi antennas, K0UO focuses on the "Lost Art" of massive, multi-acre wire arrays using the newest technology.

The Rhombic is the antenna that won WW2 for the west

The K0UO Logo using a Rhombic

A letter from Dennis, NE6I, dated June 13, 2025, expressing gratitude for a 6-meter QSO and sharing memories of a 1986 station tour.

 "As most hams need some Game, get the Gain"

Photo of the W6AM site in the 1980s before it was taken down. The K0UO nostalgic Rhombic antennas are using some of W6AM's insulators. hardware and other components. K0UO used the parts on his first Rhombic at the Rhombic Farm in Kansas for the main "East-West/ DC or LA, Rhombic" in 2012. Steve Walz K0UO contested there in the 1970s

So W6AM is Still In the AIR and ON the AIR daily.

NOTE, "Don't underestimate the performance of the Rhombic, unless you have personally built and used one. Because of their excessive size (area) covering many acres, you see their real advantage of thousands of feet of wire in the air, which creates receive signal diversity, by capturing signals at different times and different angles, vastly eliminating fading QSB, and firing out the transmitted RF in the same way. Traveling wave antennas are very unique, and unlike many other antenna in common use, and modeling will not show this major advantage." The old books say, "The gain of a rhombic with side lengths of four to five wavelengths is over 40 times that of a half wave dipole. About one half of this gain is realized by using two wave lengths to each of the four sides" From the old DoD Book, EI8IC Reprint

• Rhombic Arrays (Instantaneous): Because these are typically fixed wire structures, changing direction is done through relay switching. By having multiple rhombics K0UO is pointed in 14 different fixed directions (e.g., every 25°), you can switch between them instantly—typically in milliseconds—at the press of a button or via automated software.

• Stacked Yagi Beams (Slower Mechanical): To change the direction of a stacked Yagi beam, you must physically rotate the entire mast and antenna assembly using a mechanical rotor.

  • Rotation Time: This can take anywhere from 60 to 120+ seconds to complete a full 360° turn, depending on the rotor's speed and the antenna's mass.

  • Phasing Options: While you can use a relay switching system to select different combinations of antennas within a stack to adjust elevation or gain, you still have to wait for the rotors to reposition and move to a new target direction try doing this for 24 hours for a contest.

In short, a rhombic array farm offers instantaneous direction switching, whereas a stacked Yagi beam is limited by the mechanical rotation speed of the antenna's mounting hardware.

A NATO County "Defence Force" site that is still using Rhombic Arrays

The K0UO site now employs the Re-entrant Rhombic, achieving 90% efficiency by re-phasing the power back into the antenna rather than dissipating it in termination resistors.

Keep in mind that K0UO is comparing rhombics to large stacked single band yagis beams that were previously used on 195-foot rotating towers at K0UO, and has tested both yagis and rhombics on the RSI Corp antenna test range. "Rhombics bets Beams"

ARRL Logo is it a Rhombic Antenna? While W1AW eventually replaced the massive multi-acre wire array with a stack of aluminum beam towers in the 1980s, these original 1930s QST field maps documented a legendary domestic signal that many operators noted was never fully replicated by modern directional Yagis, Rhombics Bets Beams. You can view or reference this exact historical diagram layout directly via your active Hams with Rhombic Blog draft under the section detailing the vintage ARRL antenna layout.

W6AM 1946 antenna layout below

W6AM antenna layout 1946

TO SEE the complete Blog list check @  https://www.k0uo.com/k0uo

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The K0UO Rhombic Logo Historic Preservation: The K0UO station diligently preserves and uses components, equipment, and insulators from renowned, historic radio arrays, including those from W6AM (Don Wallace), W7YRV Roy, BBC, Voice of America (VOA), and many others.

"The K0UO station is unlike any other ham station globally," making it truly unique as a Big Gun Mega Station. This distinction arises from its exceptional capabilities, which set it apart from typical amateur radio stations found around the world. K0UO is not only equipped with advanced technology but also boasts a wide range of specialized antennas that are essential for high-performance communication. One of the most remarkable features of K0UO is its ability to construct and utilize very large Rhombic and V Beams, which are known for their excellent directional properties and efficiency in long-distance communication. These antennas are meticulously designed to optimize signal strength and clarity, allowing operators to engage in reliable communication over vast distances. The station's commitment to innovation is further demonstrated by its incorporation of artificial intelligence (AI) technologies, which enhance operational efficiency and enable sophisticated signal processing capabilities.

K0UO features the largest operational HF wire antenna in the world, a testament to its status as a premier facility for amateur radio enthusiasts. This massive antenna system is capable of handling a wide range of frequencies, making it versatile for various communication modes and conditions. The sheer size and design of this antenna allow for exceptional performance during contests and DX (long-distance) operations, where every decibel of signal strength can make a significant difference. Moreover, the station's infrastructure is meticulously maintained to ensure optimal performance year-round. The combination of advanced engineering, high-quality materials, and expert craftsmanship results in a station that not only meets but exceeds the expectations of amateur radio operators. The community surrounding K0UO is also vibrant, with operators frequently sharing knowledge, techniques, and experiences, further enhancing the station's reputation as a hub for innovation and excellence in the amateur radio world. In conclusion, K0UO stands out not just for its impressive array of antennas and cutting-edge technology, but also for its commitment to fostering a community of passionate radio operators. This makes it a truly unique entity in the realm of amateur radio, solidifying its position as a Big Gun Mega Station recognized and respected by enthusiasts globally.

"I hope others will carry on the tradition, and art of building the large Rhombic Arrays in the future". It is truly the "PHD" of wire antennas.

An email from Roy (Ham W7YRV) to Steve Walz, some of the parts now used for K0UO Historic Preservation

SEE ALL BLOGS Here, & Just Skip the first few pages, and go to the Blog List

Remote operation users

Note to contest operators, DXers, and remote users of the "K0UO RemoteHamRadio facility": You must sign a non-disclosure agreement and keep the "exact location" of the K0UO site confidential. The site hosts priority DoD/DoW projects using specific HF high-gain antennas. You will be notified if an antenna is unavailable, as per the original agreement, which states certain antennas are not guaranteed and may change without notice, following the Department of Defense utilization clause (30 days on most agreements).

K0UO https://maps.app.goo.gl/iSBoAoX9E8qs226WA

The K0UO location owner receives many inquiries annually for remote station use for DX, casual amateur radio, or contests. Due to limited access, a protocol is required. If you have an agreement, you must comply with the non-disclosure terms. While contest location disclosure is often required, stating the station is in Grid Square EM07, Barber County, Kansas, is allowed; revealing the exact location or owner/call breaches the agreement. If approved, enjoy the station responsibly.

The facility includes valuable equipment like Flex 8000 transceivers, amplifiers, advanced control systems, and massive HF antennas, including Rhombic, V beams, Delta Loop quad-beams, and more.

The agreement is confidential, prohibiting disclosure to others. This ensures sensitive information remains protected. Each agreement is customized to meet specific needs, fostering trust and communication while safeguarding interests. Breaching confidentiality can result in legal consequences and loss of trust. Respect the agreement terms and maintain confidentiality at all times.