Rohn 20, 25, 35, 40, 55, 65, Rigid Tube Export Tower Series 26KD, J, and the C Tower.
- skylarkcolo

- Dec 8, 2025
- 8 min read
Updated: 7 days ago
Rohn Tower designs are in accordance with ANSI/TIA-222-F-1996 and ANSI/TIA-222-G-2005, Class I Structures. I have used various models of Rohn towers at the K0UO Rhombic Antenna Farm and outdoor antenna test range over the years, so I put this page together.

ROHN began manufacturing towers in 1948, and the G-Series line of towers in the early 1950’s. Starting with the ROHN No. 5 tower, there was an ever present drive for a superior tower design. The No. 5 soon led to the ROHN No. 6 and continued through the No.10,11, 20, 25, 45, 55, 65, along with the R35 old Motorola & GE Contract towers, the Rigid Tube bolt together export Tower Series the 26KD, J, and the C Tower. ROHN originally coated the lightweight towers with a hot-dipped enamel coating called RohnKote. The alternative to RohnKote was hot-dipped galvanizing. The galvanized option was identified by the now famous “G” suffix added to the tower model. The G-Series was born! The numbers have settled to the four models R25, 45, 55, and 65 listed below and hot-dip galvanizing is the coating of choice for towers today. ROHN’s G-Series towers are designed for strength and versatility. The towers are constructed with high strength steel tubing or solid round legs. ROHN’s exclusive Zig-Zag solid-rod bracing provides exceptional strength. As they were in the 1950’s, each ROHN G-Series tower continues to be hot-dip galvanized for corrosion protection.




ROHN TOWER R20G to R65G
Rohn 20, 25, 45, and 65 towers use tubular vertical elements.
Rohn 20 -R55 have bolt swaged steel joints on each leg for coupling.
The ROHN 20G Tower Section is 18 gauge steel Tubing 11.25 in spacing, 1 1/4 legs. The ROHN 20G 10 Foot main Tower Section consists of 6 bays spaced approximately 18.25 inches, 10 foot section wight is 30lbs, ROHN 25G accessories fit the 20G and 20G7 tower.
Rohn 25G has 11.25 in spacing.The ROHN 25G Tower Section is 16 gauge steel Tubing, up to 190 foot, 1 1/4 OD legs, 5/16 solid bracing. The ROHN 25G 10 Foot main Tower Section consists of 7 bays spaced approximately 15.75 inches, in 7'UPS ship-able or 10 foot standard wight of 37 lbs per-section.
Rohn 35G or HW was a Motorola "Type HW" and also called The GE "Contract Tower" Is an odd-ball faced sized tower, made only for Motorola and GE. DO NOT treat it as R45, it is not that strong. The leg diameter and gauge is same as 25G and the zig zag bracing is the same size as 25G, but having an 15 inch face.
Rohn 45G has 16.75 in. leg spacing. ROHN 45GSR10 is the 10' Foot 45GSR Main Tower Section made with a 1-1/4" OD Solid Steel Rail design 7/16 solid rod bracing for Heavy Duty applications. A guyed 45GSR Tower can withstand 130 MPH Wind Loads up to 340 feet in Height. 68bb2b09e8e23_Guyed_Towers_45G_48-71.pdf
Rohn 55G is a multi-use structure that provides excellent strength for applications up to 400 feet, 17" CC on face, 1-1/2" OD, 11 ga steel legs, 7/16 solid bracing offered with either heavy steel tube or solid steel rod legs to satisfy a wide variety of needs under varied conditions. When properly installed, the standard tower will support the loads shown on various guyed and self-supporting information sheets in the ROHN catalog .Guyed Towers 55G.pdf
ROHN 5545G 20' foot 55G to 45G Transition Adapter Tower Section provides a means to join the 45G 16-3/4" Equilateral Face, 14 Gauge, 1-1/4" inch Rail Main Tower Section onto and on top of a 55G 17" Equilateral Face, 11 Gauge, 1-1/2" inch Rail Main Tower Section.
Rohn 65G is designed to provide excellent rigidity and strength in applications up to 500’.
Built on a 24 1/4” C to C equilateral triangle design, 1.90" OD leg with.145" wall, 5/8” O.D. Solid Bracing, Optional double braced sections are available, applications 340' to 500 feet. In 10 or 20 foot sections with 4 bolt flange per-leg

















RIGID TUBE TOWERS WAS THE IDEAL TOWER FOR EXPORT USE, which was only produced in the 1960-90s: Versatility, ease of assembly and an extremely efficient shipping design combine to make the ROHN Rigid Tube Tower an ideal structure for export use. The All Bolted construction means the towers can be packed in tight containers, conserving space and greatly reducing any chance for shipping damage. The three models in the Rigid Tube Tower Series are: the Type or Model 26KD Tower, the J Tower, and the C Tower.

STREAMLINED DESIGN: The streamlined design eliminates the conventional flange plate connection, replacing it with an unusually high strength multiple bolt swaged steel joint. Legs can be bundled tightly with no dead space between the major members. This design reduced the cubic foot requirements for packing by as much as 80% over conventional structures, while insuring a strong connection between sections of the assembled tower. As with all ROHN products, Rigid Tube Towers were Hot Dip Galvanized after fabrication to assure years of corrosion free use. In this process, each section of the tower is totally immersed in molten zinc, bonding 2 ounces of the zinc to every square foot of steel. Hot Dip Galvanizing protects all surfaces, inside and out, against rust and corrosion while providing an attractive finish. These towers on have a climb leg on one side.

26KD TOWER: The 26KD Tower is an 111⁄4” triangular tower with a 121⁄2” face. It is suitable for installation up to 150’ with proper guying. FEATURES: • Hot Dip Galvanized after fabrication • Ideal for export, efficient shipping • 10’ Section length • Side Rails are 11⁄4” X 16 ga. high strength steel tubing with minimum yield strength of 50 KSI • Steps are 1 • 7 Bays of bracing, 1⁄2” by 18 ga. with a minimum yield strength of 33 KSI ” X 18 ga. on one face. Like a R25 usable to 150 feet
J TOWER: The J Tower is an 18” triangular tower with a 191⁄2” face. It is suitable for installation up to 300’ with proper guying. FEATURES: •Hot Dip Galvanized after fabrication •Ideal for export, efficient shipping •10’ Section length with shorter top sections available •Side Rails are 11⁄2” X 14 ga. high strength steel tubing with minimum yield strength of 50 KSI •6 Bays of bracing, 3⁄4” by 16 ga. with a minimum yield strength of 32 KSI •Steps are 3⁄4” X 16 ga. on one face, this tower is easy to spot as it uses three bolts per leg. It is like a R55, I have a 195 foot at my Rhombic Farm which was part of an 300 foot Cable TV tower. Rohn J, is usable to 300 feet
C TOWER: The C Tower is a 24” triangular tower with a 261⁄ 4” face. It is suitable for installation up to 400’ with proper guying. FEATURES: • Hot Dip Galvanized after fabrication • Ideal for export, efficient shipping • 20’ Section length with shorter top sections available • Side Rails are 21⁄4” X 12 ga. high strength steel tubing with minimum yield strength of 50 KSI • 10 Bays of bracing, 1” by 16 ga. with a minimum yield strength of 32 KSI • Steps are 1” X 16 ga. on one face. Like a R65. Rohn C is usable to 400 feet








The K0UO antenna test range site makes use of the 4KS Walz airport, known as "Antenna University", and its surrounding area as a practical learning environment for STEM (Scientific, Technical, Engineering, & Mathematics) antenna projects in a real-world outdoor setting. The site has a large outdoor area with a variety of terrain types for conducting user defined experiments. If your group has a University aerospace or antenna research STEM program, please let me know.
The KØUO Rhombic Antenna Farm and Antenna Test Range: Home to the World's Largest amateur radio (ham), High Frequency (HF) Wire Arrays, miles of wire in the air and on the air daily.
SEE

73
K0UO/V31KW
Seve Walz












Comments