Antenna Delta Lazy (lazy Delta)
In "Radioecological" 1985 was published antenna a bit of a strange name. She is depicted a conventional isosceles triangle with a perimeter of 41.4 m. and, obviously, therefore, has not attracted attention. As it turned out, very vain. Me, just need a simple multi-band antenna, and I hung it on a small height of about 7 meters. The length of the supply cable RK-75 of about 56 km (a half-wave repeater). Measured SWR, practically coincided with that given in the "Yearbook".
Then came the opportunity to increase the height of the suspension to 13 meters above the ground. And in this case, the value of VSWR on all major Amateur bands except 80 meters, not more than 1.4. At eight-ten, its value was between 3 and 3.5 on the upper frequency range, therefore, its approval is additionally used the simplest antenna tuner. Later it was possible to measure the SWR at WARC bands. There SWR is not exceeded 1.3. The drawing of the antenna is given in the figure.
Coil L1 is wound on an insulating frame 45 mm in diameter and has 6 turns of PEV-2 thickness 2 ... 2 mm. RF transformer T1 is wound a wire mgshv on a ferrite ring with permeability of 400 HH mm, contains two windings 12 turns. The size of the beads is not critical and is selected on the basis of the supplied power. The power cable is only connected as shown in the figure, if it's included on the contrary - the antenna will not work. The antenna requires no configuration, most importantly, to sustain its geometrical dimensions. When working in the range of 80 meters, compared with other simple antennas, it loses to the transmission - small length. On receiving the difference is almost imperceptible. Measurements RF bridge G. Bragina ("P-D" No. 11), showed that we are dealing with a non-resonant antenna.
The meter response only shows the resonance power cable. We can assume that turned out to be quite universal antenna (simple), has a small geometric dimensions and its SWR is almost independent of the height of the suspension.
Author: V. Gladkov, RW4HDK, Chapayevsk; Publication: N. Bolshakov, rf.atnn.ru