UB5UG Horizontal Receiving Antenna

Credit Line: Radio # 12, 1977. P. 25

At modern city to use a separate receiving antenna may be only one variant to be on the Air. Interferences from nearest electronics devices could force it. Below here it is described receiving antenna from far 70-s that may solve the hard modern situation.

The antenna works at 80-, 40-, 20-, 15- and 10- meter Bands. Antenna receives mostly radio waves having horizontal polarisation. Industrial electrical interferences as usual has vertical polarisation. Commercial and ham radio- stations as rule have antennas with vertical polarisation. So, the antenna allows decrease at receiving input both as interferences and signals from nearest radio- stations. At right installation the antenna reduces unwanted signals with vertical polarization up to 20- 30- dB. However the antenna would effectively work for receiving DX station because the stations have as vertical as horizontal components.

Antenna has circle diagram directivity in horizontal plane and 8- shape diagram directivity in vertical plane. It is horizontal loop antenna that feed by transmission line in standing wave mode.

Figure 1  shows design of the antenna. Loop antenna made from two length of the same coaxial cable (item P/2). Feeder L made from the same coaxial cable as loop of the antenna. It is possible use any coaxial cable- 50 or 75- Ohm.

Front Cover Radio # 12, 1977

Antenna has electrical length lambda/2 at 80- meter Band, lambda at 40- meter Band, two lambda at 20- meter Band, three lambda at 15- meter band and four lambda at 10- meter Band. Receiving part of the antenna is only loop. When the loop made symmetrically relative to the axis AB the part L cannot participate in receiving. Antenna has input impedance in several Ohms. The antenna may be matched with receiver by some known methods. Antenna has efficiency in several percent at 80- meter Band to several tens at 10- meter band. It is possible to increase the efficiency of the antenna at low bands by increasing of the diameter of the antenna loop.

Title of the Article

www.antentop.org

Page- 78