top of page

K0UO Rhombic array antenna control box

K0UO RHOMBIC ANTENNA FARM

cursor_click_pointer_mouse_select-512_ed

Screenshot_20250929_203841_LinkedIn_edit

The Mighty Rhombic is the "KING of Wire Antennas".

This is Scientific Technical Engineering, & Mathematics (STEM), Blog Site

If you have an big HF wire antenna project, let me know if I can help in anyway

The blog site has design, modeling, and construction information for building big HF Rhombic arrays, V-Beams wire arrays, Curtain antennas, baluns, VOA sites, LPDA Logs, W6AM, W7YRV, Ham Radio, Feed-lines, Beverage receive antennas, BOG, Traveling Wave antennas, Delta loop wire beams, antenna vibration dampening, Icom Diversity receive for the IC7610 and IC7760. Also blog topics in use at the K0UO Rhombic farm and antenna test range, and 4KS Walz Airport at Kiowa, KS.

The K0UO amateur ham radio station, antenna testing range site "Antenna University", and The Rhombic farm has the use of over a thousand acres around the main antennas for far field measurements, using a portable tower and drones loaded with calibrated RF EME survey instruments (used for Amateur Radio, STEM, DOD, school or University Research, and Commercial).

This site can be viewed in numerous languages check your browser and language flag

TO SEE,

the complete Blog list check @

https://www.k0uo.com/k0uo

Then click on each blogs Header that you want to read.

The ARRL, RSGB, Switzerland, and so many other amateur radio organizations use the Diamond Logo, which looks like a Rhombic antenna.

Steve Walz known as K0UO (his FCC Amateur radio call), is working on the "Lost Art of Rhombics" with four of these large wire antennas, at 100 to 160 foot high, and three 1200 foot V-Beams (VEE) antennas at the Kansas QTH. Which are beaming to the fourteen main DX areas, and with phasing adding more steering. There is also information on large distributed fed curtains arrays, LPDA, and beverage receive antennas. K0UO is home of the Re-entrant Rhombic, which is 90% efficient by re-phasing the power instead of heating up termination resistors.

Also see the page on Beverage RX antennas.

I contacted 200 countries on 160 meters, and it wouldn't have been possible without the beverage antennas.

The K0UO antenna farm is proudly using parts from many legendary stations, to continues the tradition they started with the big arrays, like the VOR (Voice of America), Armed Forces Radio, W6AM Don Wallace, BBC, Art Bell W6OBB, W7YRV Roy Callison, and others. So symbolically those large historic stations are still, "On the Air Daily" by K0UO using an extensive array of towers and antennas.

See my call on QRZ, https://www.qrz.com/db/K0UO, or type in my call K0UO for more information and photos. Each Rhombic antenna uses 1000s of feet of 3/8" cable for the array wire, covering many acres each. They are erected on numerous towers and 100 foot wooden utility poles, also the site has three large V-Beam antennas which are over 1200 foot long each. Miles of wire in the air and on the air, spread out over many acres. "Build Them and the DX will Come"!

The K0UO Rhombic site is the largest and highest gain wire antennas array farm, currently still in use anywhere in the world.

The KØUO Rhombic Antenna Farm in Kansas, consist of many acres, with "Miles of Wire in the Air & On the Air".

A HF Rhombic antenna is an excellent choice for commercial, maritime shore stations, military, broadcasting, frequency agile, requirements, high speed traders, diplomatic, EME, and big gun contest ham amateur radio stations.

The complete Blog list at the botton of the page

https://www.k0uo.com/k0uo

Then click on the HEADER of the Blog that you want to read.

The K0UO antenna test range site makes use of the 4KS Walz airport and its surrounding area as a practical learning environment for STEM (Scientific, Technical, Engineering, & Mathematics) antenna projects in a real-world outdoor setting. If your group has a School or University aerospace or antenna research STEM program, please let me know.

Amateur Radio calls, K0UO and V31KW

SEE

https://www.linkedin.com/in/general-steve-walz-698279219?utm_source=share&utm_campaign=share_via&utm_content=profile&utm_medium=android_app

SEE, THE COMPLETE BLOG @

https://www.k0uo.com/k0uo

SEE Steve's RF Testing Team overview, Founder of RSI Corp, https://en.wikipedia.org/wiki/RSI_Corporation

K0UO Rhombic antenna Farm

Search

Math for the Rhombic & V Beams Array

skylarkcolo
Apr 23, 2024
2 min read

Updated: Nov 22

https://www.k0uo.com/post/rhombic-math-design

Table with frequency data for a rhombic antenna USED BY k0uo AT THE WORLDS LARGEST hf ANTENNA FARM. Rows and columns are color-coded. Includes a diagram and text about gain and direction. — Chart detailing rhombic antenna specifications and measurements, including frequency ranges and dimensional values for both un-terminated and terminated configurations, with adaptable frequency settings for user customization.

The above is all the info/data that you need to build a Rhombic

Graph labeled "Design Chart for Constructing Rhombic Antennas for Maximum Output," showing curves and gridlines. Text at bottom reads "Figure 190."USED BY k0uo AT THE WORLDS LARGEST hf ANTENNA FARM — Design chart illustrating the relationship between wave angle, height, and tilt angle for optimizing the construction of rhombic antennas for maximum output.

Diagram illustrating wave propagation with angles and points labeled. Includes terms like wave direction and ground. Caption: Fig. 1—Horizontal rhombic antenna dimensions.
K0UO using this for the install of his large antennas — Diagram illustrating the dimensions and phase angles of a horizontal rhombic antenna relative to wave direction and ground reflection.

L. B. Cebik, W4RNL Model below

Diagram of V-array antenna patterns at 3.5 MHz. Shows two patterns: unterminated and terminated, with concentric circles and lines. USED BY k0uo AT THE WORLDS LARGEST hf ANTENNA FARM — These are for 80 meters and need to be one half wave high to control ground loss

Diagram showing rhombic antenna patterns at 3.5 MHz. Two azimuth patterns labeled Un-terminated and Terminated are compared below. USED BY k0uo AT THE WORLDS LARGEST hf ANTENNA FARM

Table compares performance of 3.5-MHz arrays: gain, angle, front-back ratio, beamwidth for single long-wire, V, and Rhombic arrays, both terminated and unterminated. USED BY k0uo AT THE WORLDS LARGEST hf ANTENNA FARM — Performance comparison of 3.5-MHz long-wire arrays: The table showcases gain, take-off angle, front-back ratio, and beamwidth for single long-wire, V, and rhombic array types, comparing unterminated and terminated states. Notably, the rhombic terminated type offers the highest gain and front-back ratio.

More into at https://antenna2.github.io/cebik/content/ao/ao11.html

WA7ARK recommends NEC5 (newer MOM algorithm) from Lawerence Livermore Labs greatly adds to modeling capability (adds buried conductors) and makes it much easier to write models (many less restrictions compared to NEC2d)

I now model all my antennas using NEC5 and HFTA (High Frequency Terrain Analysis) to evaluate the take of angle of the various antennas over real ground, and use 3/8" Triple Galvanized Wire Rope Cable is used for the antenna wire.

The K0UO amateur ham radio antenna range, and testing site has the use of over a thousand acres around the main antennas for far field measurements, using a portable tower or drone loaded with calibrated RF EME survey instruments (used for ham, DOD and Commercial), see the far field test page. https://www.k0uo.com/post/model-and-then-do-far-field-test

The K0UO antenna test range site makes use of the 4KS Walz airport and its surrounding area as a practical learning environment for STEM (Scientific, Technical, Engineering, & Mathematics) antenna projects in a real-world outdoor setting. If your group has a university aerospace or antenna research STEM program, please let me know.

See the other pages on K0UO for much more design info

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

To build a 20 meter Rhombic to get 10D takeoff

https://www.youtube.com/watch?v=R-q6pmGJggo

https://antenna2.github.io/cebik/content/amod/modeling.html

Recent Posts

The K0UO Ham Radio Station: A Comprehensive Guide to Rhombic HF Antennas

The K0UO Ham Radio Station: A Comprehensive Guide to Rhombic HF Antennas

Rhombic Antenna Array

Rhombic Antenna Array

Broadband antenna low SWR with very high gain 20 db

"KING of Wire Antennas" is a Rhombic"

bottom of page