ANTENTOP- 01- 2011, # 015

Antenna "Strela"

The dimensions of the 15- meter Band antenna Strela were calculated with formulas from the Figure 2. It has got: 341.0- 237.0- 104.0- cm. However the real antenna did not shot the resonance. Figure 6 shows parameters of the antenna at the frequencies from 1 up to 30- MHz. At the figure Red color shows SWR Green color shows R Blue color shows Z. The real Antenna had resonance at 20- MHz. Input impedance of the antenna was near 30- 40- Ohm at the frequency. The resonance frequency of the antenna was lowered due to the low height of the installation of the antenna.

The antenna was tuned in to resonance by shortening of the antenna parts. The right dimensions (at UA3NFI installation) were: 325.0- 225.0- 100.0- cm. Figure 7 shows parameters of the antenna at the frequencies from 1 up to 30- MHz. Input impedance of the antenna was 60- 75- Ohm.

The antenna worked fine. However UA3NFI could compare the antenna only with dipole for the 10- meter Band that was tuned to the 15- meter band with ATU. Antenna Strela gives +10- dB over the 10- meter dipole.

Figure 6 Parameters of the Antenna Strela at the frequencies from 1 up to 30- MHz before tuning in to resonance

Figure 7 Parameters of the Antenna Strela at the frequencies from 1 up to 30- MHz after set up to the resonance

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