Finnish radio Amateur Pekka Pucca (OH1NE) from Turku sent to the editor with a description of its multi-band dipole designed for operation in the range of 3.5; 7; 14; 21 and 29 MHz. As the author of the letter, the dipole gives good results 3.5; 7; 14 and 29 MHz (with a low standing wave ratio). Quite good results and low standing wave ratio obtained on 21 MHz.
Dipole ham OH1NE shown schematically in Fig. 1.
The length of each of the arms is equal to a quarter wave range of 3.5 MHz (2* l/4=2*20,6 m). Matching transformer is from a two-wire 300 Ohm line and has a length of 17.6 m in the case that the length of the feeder is greater than the length of the matching transformer (feeder for this antenna can be of any length). The lower end of the matching transformer, as shown, is open.
Cable matching transformer can be left free-hanging, may be suspended under the feeder (but not too close) and, finally, they can join together (but not too tight).
Author: Pekka Pucca (OH1NE); Publication: N. Bolshakov, rf.atnn.ru