DIY a half-wave dipole anti-typhoon antenna , how to make a half-wave dipole anti-typhoon antenna
If you think it is too difficult to DIY the antenna, we have the dipole anenna in stock, please Click here to get our dipole antenna
Half-wave dipole antenna, the feeling produced good results, especially the part of the Friends of the machine requirements in detail Figure words, re-demonstrate how to make a half-wave dipole antenna FM radio receiver, because I am a computer professional, notradio professional, a lot of things from books and online learning to the wrong place, please criticism.
(Of course, the half-wave dipole antenna is not the best, because of the practical antenna design and production, "a book referred to in section 11: relative and full to the antenna, the half-wave dipole antenna gain 2.15db, three element Yagi's gain of 7.7db, so if you need a DX distant FM radio stations, or Yagi antenna effect. Yagi antenna is defective, the direction is too strong for everyday use is not convenient, can not listen to a ran outside turn the antenna)
A theory to prepare:
FM radio band center frequency of 98MHZ, wavelength = 300 / f = 300/98 = 3 m 1/4 wavelength of 0.75 m
However, the length of the antenna oscillator is not exactly 1/4 wavelength, because of the speed of waves moving in the wire in a vacuum, generally short, so there is a shortening factor
Oscillator length of the (286 / f) / 4 = 0.73 m
Two materials ready:
Oscillators - 6 square copper two long 80 cm
Quarters of PVC water pipe two 80 cm long for the bar, the best Liansu brand, good quality
Quarter of the PVC pipes one for the vertical rod, four meters long (length top)
Sixth of PVC pipes a 3.5 m long and eighth of PVC pipes a long 3 meters (after the finish of the entire antenna, four in charge in six charge, and then six in charge in eight charge, to strengthen the main lever strength, practice has proved, so that the total length of 4 m rod can withstand typhoon Nuri and Hagupit)
Tools - hacksaw electrical tape electrical waterproof glue Bouza with a tape measure scissors pliers PVC pipe glue glue
If you think it is too difficult to DIY the antenna, we have the dipole antenna in stock please Click here to get our dipole antenna
Three fixed oscillator
Both ends of the oscillator using waterproof tape wrap, then tie oscillator crossbar
If you think it is too difficult to DIY the antenna, we have the dipole antenna in stock please Click here to get our dipole antenna
Connection bar and the main pole
Bar and rod with adhesive glue up four in charge of the three links
Five electric iron oscillator with 75-ohm coaxial cable welding to use waterproof electrical tape to wrap the
Six balun
Dipole antenna impedance is 75 ohms, the two halves of the dipole is symmetric (ie, balanced) and coaxial (unbalanced) connections need to have a 1:1 balance - balun (balun is). "This converter is the most simple production approach is 4-5 laps around the cable diameter of about 10-20cm
Seven to strengthen the main lever
Four in charge in six charge, and then six in charge of eight in charge of strengthening the intensity of the main rod, practice has proved, so that the total length of 4 m rod can withstand Typhoon Nuri and Hagupit
Eight joints
Nine stand up effect (the oscillator from the ground at least 2 m, the higher the better, if the roof, but also at least two meters away from the roof, if you stand on the roof, pay attention to mine)
Our other product:
