Dipole its symmetric system with ~72ohm in center.
Wiki:
The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole with a radiating structure supporting a line current so energized that the current has only one node at each end.
The most commonly used is the centerfed halfwave dipole which is just under a halfwavelength long. The radiation pattern of the halfwave dipole is maximum perpendicular to the conductor, falling to zero in the axial direction, thus implementing an omnidirectional antenna if installed vertically, or (more commonly) a weakly directional antenna if horizontal
A halfwave dipole antenna consists of two quarterwavelength conductors placed end to end for a total length of approximately L = λ/2. The current distribution is that of a standing wave, approximately sinusoidal along the length of the dipole, with a node at each end and an antinode (peak current) at the center (feedpoint)
How to build halfwave dipole antenna for hf:
1.Need 2 copper wire 14mm diameter and λ/4– use this table:
Wavelength table
Band  MHz  λ  λ/2  λ/4 
160 meter  1,81 MHz  165,75 Meter  82,87 Meter  41,44 Meter 
80 meter  3,6 MHz  83,33 Meter  41,66 Meter  20,83 Meter 
60 meter  5,35 MHz  56,07 Meter  28,04 Meter  14,02 Meter 
40 meter  7,1 MHz  42,25 Meter  21,13 Meter  10,56 Meter 
30 meter  10,1 MHz  29,70 Meter  14,85 Meter  7,43 Meter 
20 meter  14,15 MHz  21,20 Meter  10,60 Meter  5,30 Meter 
17 meter  18,1 MHz  16,57 Meter  8,29 Meter  4,14 Meter 
15 meter  21,2 MHz  14,15 Meter  7,08 Meter  3,54 Meter 
12 meter  24,95 MHz  12,02 Meter  6,01 meter  3,00 Meter 
10 meter  28,4 MHz  10,56 Meter  5,28 Meter  2,64 Meter 
Note that the shortening factor of the wire is not included in the table. So the antenna will be about 5% shorter in reality.
2. Balun 1:1 (without balun you will be have many common mode. Balun need for current symmetry and choke commonmode)

Balun for dipole 1:1 (DB11K)Product on sale€70.00

Balun for dipole 1:1 (DB1143)Product on sale€65.00

Balun for dipole 1:1 (DB1152)Product on sale€70.00
3. Coax 50ohm 1/2 lamda length (Halfwave coax repeater) – use this link for calculate coax length: (use Freq and shortening factor anly) – https://docs.google.com/spreadsheets/d/1Ww9v5mr89MIzynbZVK7KeMNxyqpsoXb5VZy7sDfUOY/edit?usp=sharing
Balun 1:1 (without balun you will be have many commonmode. Balun need for current symmetry and choke commonmode)
Balun:
Balun is an electrical device that converts between a balanced signal and an unbalanced signal. Our dipole its strongly balanced device, our coax its unbalanced device.
Balun materials:
Wire copper or silverplated (much better) 0.50.7mm 100300wt
Core:
FT14043 – 110 mhz 1024 mhz 3054mhz
FT14052 – 13 mhz 330 mhz 54mhz
Wire copper or silverplated (much better) 1.21.5mm 5001000wt
Core:
FT24043 – 110 mhz 1024 mhz 3054mhz
FT24052 – 13 mhz 330 mhz 54mhz
FT240K – 13mhz 354mhz