After 10 years of experimentation I came to the conclusion that the construction on the HF-bands of omnidirectional antennas is impractical primarily because of poor reception.

The lack of scarce aluminum tubes prompted the idea to do a modification of the wire antenna PA0LU on 14 MHz [1]. The essence of the revision is that instead of straight dipoles are bent (Fig.1), and midpoints of dipoles mounted on the traverse, which is welded to the segment of the pipe, installed in mast to the bearing (Fig.2).

Two-element antenna
Fig.1

The antenna tuning is the same as in [1]. For rotating the antenna removed stretch nylon that secures the ends of the vibrator and the Director, and then (manually or electrically) is set traverse, after which the ends of the elements are fixed in the new situation of stretch marks.


Fig.2

Similarly, you can make and three-element antenna. On the antenna (14 MHz) when operating CW power 40 W held connection with CX, LU, USA, JA.

Accordingly, increasing the size, the antenna can be used on the LF bands.

Literature

1. K. Rothammel. Antenna. TRANS.with it., 3-e Izd., extra - M.: Energy, 1979,p. 81-83.

Author: V. Chernogorov (UA1ZFC); Publication: N. Bolshakov, rf.atnn.ru

 

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