Momobeam Mono3-40FS Monoband Yagi Antennas

Momobeam Mono3‑40FS Monoband Yagi Antennas are full‑size, three‑element antenna systems engineered for exceptional performance on the 40-meter (7MHz) band. Delivering a SWR of < 1.5:1 across 300kHz, these antennas provide strong gain and an excellent front‑to‑back ratio, making them ideal for operators who demand maximum efficiency and reliability on 40 meters.

Unlike many 40‑meter Yagi designs, the MONO3‑40FS uses no hairpins or additional matching devices. The antenna is fed directly, and a high‑quality 3kW RF choke—included as standard—ensures proper isolation and trouble‑free connection to your coaxial feedline.

Built on a rugged square boom, each antenna arrives with an assembly tool, spare hardware (bolts and aluminum tubes), and clearly labeled components. All hardware is supplied in separately marked bags, and every aluminum element is individually labeled to make assembly straightforward and accurate.

This antenna is constructed as a heavy‑duty system, designed to withstand the demanding mechanical stresses that accompany a full‑size 40‑meter Yagi. The element plates are made from thick, U‑shaped aluminum, and each element is reinforced with both horizontal and vertical tie rods for superior rigidity. Because of the antenna’s large physical size, specialized mechanical solutions have been incorporated to ensure long‑term durability and structural integrity. The telescopic elements begin with a substantial 2.36-inch starting diameter for added strength.

Designed for serious installations, the MONO3‑40FS requires a heavy-duty rotator and supports typical mast‑mount configurations.

MONO3-40FS Features and Specifications:

• RF Choke Balun: 3kW included

• Bandwidth@ S.W.R. ≤ 1.5:1: 300kHz

• Longest element: 75.46ft. (23m)

• Power Handling: 10kW

• Wind Area: 22.6 sq. ft. (2.1m²)

• Wind Load: (80 MPH): (482N) 355.5 ft. lbs.

• Wind Survival*: 100 Mph (160 Km/h)

• Tower Leg/Mast Diameter: 2.0-2.36in. (50/60mm)

• Tower Lift Side: 2.95ft. (90cm) above the tower top Weight: 330.70lbs. (150kg)

• Feedline Connector: (1) 50-Ohm UHF SO-239 female

• Tubes and Plates: Aluminum alloy 6061T6

• Hardware: stainless steel

• Insulating Clamps: polypropylene, UV resistant