ANTENTOP- 01- 2018 # 022

RN3DEK 4- Element Antenna for the 145- MHz Band with Gamma Match

RN3DEK 4- Element Antenna for the 145- MHz Band with Gamma Match

By: Yuriy Skutelis, RN3DEK

Credit Line: Forum at cqham.ru

There is presented 4- element antenna for the 145- MHz Band. Antenna has good SWR at the band. Antenna does not require follow to strictly dimension of the elements. So the antenna may be done ever by a ham who has no large experience in the antenna building.

Antenna has 50- Ohm input impedance that allows feed the antenna directly by 50- Ohm coaxial cable. Figure 1 shows schematic of the antenna. Figure 2 shows design of the Gamma - Match. Antenna reflector antenna made of tube/rod in diameter of 5- mm. All others antenna elements of the antenna made of tube/rod in diameter of 8- mm. Gamma match made of wire/rod in diameter of 2.5- mm.

The antenna has reflector with bent ends. It is done to improve F/B ratio. Anyway you may play with model of the antenna in MMANA and check what you could reach.

Figure 3 shows Z of the antenna. Figure 4 shows SWR of the antenna. Figure 5 shows DD of the antenna.

73! RN3DEK

Figure 2 Design of the Gamma – Match.

MMANA File of the RN3DEK 4- Element Antenna for the 145- MHz Band may be downloaded at:

http://www.antentop.org/022/RN3DEK _4_el_gamma_022.htm

Figure 1

RN3DEK 4- Element Antenna for the 145- MHz Band

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