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The ON4IQ 6m array

The antenna system

Main antenna is a stack with 4x 6M9KHW by (15m long boom 12.7dBd) with full azimuth, PST71 rotator and elevation control with 36 ” actuator. Phaselines are 1/2” hardline , loss <0.25dB and tuned within 0.02%. The main feed line is a 1- 5/8" coax , loss <0.25dB. Total loss antenna to rig <0,52 dB .Sloping ground gives me a take off angle lower than over flat ground. As a backup antenna I have a 4 of the PA5070 15el by YU1CF.

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Antenna central point is at 110m asl. The antenna H-frame is about 9.1m by 8.4m and made out of welded steel tubing. Weight is >150kg for the frame, and complete structure is >200kg. The antenna was simulated in EZNEC, taking into account the H-frame. This is the ONLY correct way to evaluate an array. Often one sees a rather big influence of the supporting structure on the array performance. VE7BQH added that even the feedline will influence the pattern, this is very noticable on cross polarised antennas. .

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SWR on the array is better than 1.2 for the range 50.0 to 50.4 MHz. Phasing harnass was cut within 1mm precision. Plots taken on HP8753 network analyser. The return loss of the phasing harnass is better than -49dB.

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Radio horizon

Radiohorizon is excellent, almost 360° negative horizon giving massive ground gain and low angle take off. Just AZ 60°, a hill blocks to 0.6° elevation but hardly noticable impact.