Others Hams with the Rhombic ARRAY

K0UO 100 foot Rhombic poles and wires.

W6AM

In the 1950s to 1970s W6AM had many 1000 footers, and one was 1500ft. In fact I am still using some of W6AM's hardware on my 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.

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, 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 is planning to shut down the station and move back to Germany.

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

Ian VK3MO sent me 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 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.

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

About using parts from W6AM

Photo of the W6AM site in the 1980s before it was taken down

Ian VK3MO sent me 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 the objective. 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. (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

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.

Below, THE ARRL OLD ANTENNA LAYOUT 1937, FROM QST

Diagram illustrating the reception patterns of the W1AM diamond rhombic antenna across North America, with indicated gains and losses measured using an HRO receiver. The sketch provides a general overview of antenna performance, influenced by factors such as transmission conditions and station location relative to minor lobes. From an old QST

W1AW Rhombic in use up to the 1980s

Is it a Rhombic Antenna?

W6AM 1946 antenna layout below

W6AM antenna layout 1946

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