Introduction Amateur radio Anténa DL7KM to 432 / 435MHz (70cm)

Anténa DL7KM to 432 / 435MHz (70cm)

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Anténa DL7KM na 432MHz
DL7KM antenna for 432MHz

DL7KM advantage of the antenna is 70cm wide bandwidth, where for PSV < 2 it is up 30 MHz. This makes production less demanding antenna is not sensitive to the surrounding environment (other antennas, mast).

The simulation of the antenna DL7KM mman
The simulation of the antenna DL7KM mman

The second advantage of this antenna also referred to as dual quad or eight less separation of horizontal and vertical components making it more suitable than linearly polarized antennas, eg. oil.

The principle of the antenna DL7KM
The principle of the antenna DL7KM

The base antenna emitter sides of the square 170 mm. It is made of 3 mm welding wire. The power points the wire is drilled and screws are attached solder lugs, which connects a coaxial cable. For simplicity it is designed Symmetrization a coaxial cable is connected directly to the radiator. Coaxial cable is of course terminated N connector.

Reflectors with a diameter of 6 mm to 350 mm long and 92 mm are placed behind the radiator. The distance is 170 mm reflectors. The alternative is reflector wall.

The mechanical design is based on my case to the turned holder. It provides not only handle the radiator but also fix the coaxial cable. The whole structure is so very strong.

DL7KM at 432MHz, antenna gain and radiation pattern
DL7KM antenna for 432MHz, antenna gain and radiation pattern

According to the simulation born achieves such antenna profit of about. 7,3 dBd a F/B pomer 20 dB. The width of the radiation lobe in the horizontal plane of the 3dB 70 °.

Documents for production DL7KM, see the OK1VM or http://sa555.blogspot.com/2016/07/435mhz-biquad.html

Detail aerial DL7KM
Detail of the central mount antenna DL7KM
Grip of the central antenna reflefktora DK7KM
Grip of the central antenna reflefktora DK7KM
Handle reflefktora antenna DL7KM to 432MHz
Handle reflefktora antenna DL7KM to 432MHz
Power coaxial cable with N connector
The power antenna coaxial cable is terminated DL7KM N connector (female)

Update 07.07.2019 – the measurement of the antenna by means of a vector analyzer within 310 – 510 MHz signaling adaptation to the desired frequency 435 MHz:

The measurement using the VNA DL7KM within 310 - 510 MHz
The measurement using the VNA DL7KM within 310 – 510 MHz
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William OM0AAO / OM0A
Since I started regularly participate in the amateur race, separately for the first VHF, later in the club OM3RKP also VKV. Since gaining access to the TA to work in this area only, primarily contesting (CQWW, IARU HF, SSB Liga, Dippeth and other).