Category Archives: Antennas

Ampegon to Install Shortwave Array Antenna

From the pages of Radioworld.com  comes this news:

“Ampegon says it is about to deliver and install its first rotatable shortwave high-power array antenna on the North American continent.

The system, which will be installed WBCQ in the United States, is designed for the transmission of shortwave signals of up to 500 kW, the high-power antenna offers different radiation patterns, an antenna gain of up to 23 dB and uses a technology characterized by a single-shaft structural design.

The tubular shaft with a diameter of four meters acts as a rotatable and supporting axis that is able to absorb static and dynamic forces originating from antenna components. This, explains Ampegon, allows the system to function under extreme weather conditions.

The antenna is made up of a low-band and a high-band array antenna, positioned back to back, each equipped with a reflector screen. Thus, WBCQ can access all shortwave frequency bands between 6 MHz and 26 MHz.

In addition, Ampegon points out that the computer-controlled and monitored system offers unlimited rotation capacity and will turn toward the coverage area using the shortest possible path. Intelligent drive control ensures the large rotating part of the structure is jolt-free, starting and braking to standstill with a high rotation speed of 1.2 degrees per second and a positioning accuracy of <1degree.

The system also features DC grounding, a minimal number of insulators and no insulation in structural parts.”

Should make their transmissions to the UK and Europe more audible.

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The true story of the Yagi Antenna

From the DXZONE comes this interesting article on the development of the Yagi antenna.

Yagi antenna history

As many of you may already know, the full name of this antenna is Yagi-Uda Antenna.

The origin of this name is derived by the surname of two Japanese inventors that designed this antenna for the first time at the beginning of the 1920’s.

Yagi Antenna US Paten
Yagi Antenna US Patent Source http://www.uspto.gov
The two inventors were, Hidetsugu Yagi(1886-1976) and Shintaro Uda (1896-1976)  both professors at the Tohoku University Japan.

What not everyone knows is that the original concept of this antenna has to be attributed to Shintaro Uda(Yagi’s assistant professor) that in 1926, first described this antenna at Tohuku University in Japan,  in the IEEJ (Japan).

Hidetsugu Yagi , who worked in the UK, USA and Germany, applied for patents on the new antenna both in Japan and the United States.

The Japanese patent was immediately issued in 1926 with nr. 69115 while the U.S. patent 1,860,123filed in 1926 was issued later in 1932.

While the Japanese patent was properly attributed to both the inventors, the US patent was assigned tothe Dr. Yagi.

Japanes Patent 69115
Japanes Patent 69115 source aktuellum.com

Dr. Yagi is listed among the ten Japanese great inventors by the Japan Patent Office for this very invention, and has been president of Japan Amateur Radio League (JARL) in 1946.

Although no one can ever tell us how much authorship should be attribute to Professor Yagi rather than Professor Uda , certainly we should attribute the right authorship to this antenna by naming it always as Yagi-Uda.