ANTENTOP- 01- 2013 # 017

RA3AAE Antenna for the 10- and 2- meter Band

Figure 1 Design of the RA3AAE Antenna for the 10- and 2- meter Band

Where h is the height from the radials to the feeding terminals. The resonance frequency of the 10- meter Band antenna does not change at the shift of the feeding terminals. Moreover, at the antenna design the shift of the feeding terminals (for the 10- meter Band) allows to place the vertical antenna for the 2- meter band higher on to the antenna design. It has sense at the limited (on to high) installation of the antenna.

Vertical Dipole Antenna for 2- meter band influences to resonance frequency of the 10- meter Band antenna. The influence is lowered the resonance frequency of the antenna. So it is possible compensate the influence by the shortening of the vertical (item 2). This influence may be calculated theoretically but the simple way is practically find it. For the described here antenna it needs to be shortened the vertical on to 100- mm while the antenna would be tuned to the resonance.

Table 1 shows SWR of the RA3AAE Antenna for the 10- and 2- meter Band.

Vertical of the antenna (item 2) made of aluminum wire in diameter of 8- mm (0- AWG). Vertical Dipole Antenna (item 1) made of duralumin tube in diameter of 30- mm (diameter 1-1/2- inch). Antenna radials (item 3) made of antenna wire in diameter 1...2- mm (12- 18 AWG). Vertical (item 2) is fixed on to wooden mast with help of insulators. Each radial (item 3) has two insulators at the end.

The antenna needs lighting protection. Closed Stub (item 5) does this function. The stub has electrical length ¼ lambda at 10- meter Band and 5/4 lambda at 2- meter Band. The stub has high impedance at the bands and this one does not affect to the antenna- feeder system.

Table 1 SWR of the RA3AAE Antenna for the 10- and 2- meter Band

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