The review of antennas the Delta-2
Continuing the review on antenna type Delta, which was launched earlier on the basis of enquiries and explanations in particular will focus on antennas for multi-band option, and located at low elevation suspension, as well as devices for their alignment with the cable agriculture with standard coaxial cables commonly used in ham radio type and RK50 RК75.
In Fig. 1 shows the antenna of the Delta the upper edge of which is the height of 17 meters.
Fig. 1For matching the antenna and receiving their negotiationsthe applied a matching ladder length - of 10.3 meters and a width of 10 cm, the material from which made antenna and ladder - copper wire with a diameter of 1.5 - 2.0 mm. To negotiate stairs with cable RK50 applied balun cable RK75 having 10 turns of cable located a coil to a coil diameter - 20 cm, total length cable cut equal - 6,95 m Antenna works great on ranges 80-40 meters. When converted can work with this matching system and on other bands.
In Fig. 2 shows antenna "Delta" which is agreed with coaxial cable RK50 the coordinator transformer with a ratio of input and output resistance 1:4.
Fig. 2The number of turns of the transformer to 7 turns each of the windings of the withdrawal made from the middle. Connection diagram the windings shown in RIS. The antenna is suspended from a height of 18.3 meters.
The antenna is shown in Fig. 3 is placed horizontally the earth's surface and has the shape of a square with equal parties.
Fig. 3This antenna has low profile suspension that it can be applied where there is no possibility to hang the antenna is not vertically and not at an angle. Input impedance the antenna due to the low height of the suspension is different resistance bands, making it difficult to apply, as a single antenna in multi-band version, but for each band made antenna and agreed on the proposed scheme works perfectly, but her naturally has all the downsides of low-lying antennas.
The table gives the dimensions of the sides of the antenna ranges and length matching cable cut RK75 Om Canvas antenna made of copper wire with a diameter of 1.5-2 mm.
Author: A. manoylenko (UN9LK); Publication: www.cxem.net