DVB-T2 digital television antenna
What is required for the assembly of the antenna
- Barbecue grill;
- Spray paint for cars;
- Solvent or acetone;
- A set of drills for conventional drills;
- Coaxial television cable - no more than 10 m;
- Half meter PVC pipe HV, diameter - 20 mm;
- Metal dowel for drywall;
- Copper wire for antenna vibrator, core diameter - 2-3.5 mm;
- Two thin metal plates.
- Soldering iron powerful 100 W;
- Screwdriver with nozzles;
- Hot melt glue gun;
- Pliers, hammer, nippers;
- Paint knife, tape measure, pencil.
Getting to the manufacture of the antenna
Making a frame-vibrator
We measure the necessary length of a copper wire with a margin of about 1 cm. You can also use a copper or aluminum tube, with a diameter of up to 12 mm.
We clean the copper conductor from the insulation, and level it with a hammer on a hard surface. Mark the middle and make a 90 ° bend. The most accurate way to do this is to do it in a vice, lightly pressing the copper core and leveling it with a hammer.
According to our calculations, the sides of the squares will be 125 mm. We mark them with a tape measure, and we make bends.
At one end with a side cutter, we bite off a small fragment, making the tip pointed at 45o. After bending the second square, we perform the same procedure, biting off the final end of the core. Squares for this can be slightly straighten.
On the middle bends of squares we achieve a distance of 10-12 mm. At the ends we make shallow cuts with a file. This will help us pull together both loose ends, and fix them with thin copper wire.
With the help of liquid rosin or flux we solder the bend with a soldering iron. This must be done on all sides of the copper core of the vibrator.
We clean the coaxial cable by 4-5 cm. We twist the braid or the outer conductor into a single wire, wind it around one of the bends. Solder it to the copper core with a soldering iron.
We clean the insulation of the inner conductor, and also wind it around the next bend of the frame. It is necessary to solder it carefully holding insulation with pliers, since it can simply shift from the temperature from the center. We first heat the frame in the soldering zone, and only then the conductor itself.
Fix the coaxial cable liner with a nylon tie, degrease with a solvent and isolate the soldering points with a hot glue using a gun. To correct defects in the resulting molded glue can be a hairdryer.
Cooking a reflector
As a reflector or reflective screen, use an inexpensive barbecue mesh. This is not a bad material, since even steel samples of such products are coated with a corrosion-resistant anodized coating, not to mention stainless steel. A heat exchanger from a modern refrigerator or a grid-dryer for dishes is also suitable. The main thing is that this element should not rust in air as much as possible.
The reflector grille should be larger than the frame of the vibrator, but not necessarily symmetrical. Cut off the grids from the handle, they will be superfluous in our design.
We place the antenna frame in the middle of the reflector, and mark the place of its fasteners. For fixing, you can use two plates of any metal. Bend them along the grate, and drill holes with a diameter of 5 mm.
We collect the antenna
Cut off two pieces of PVC pipe with a length of 75 mm, and screw it into the end of each using a self-tapping screw, cutting off the protruding parts.In drywall dowels, break off the pointed tips, and screw them into the opposite end of the tubes.
We fasten both PVC racks to the slats on the reflector with screws. Tin the frame at the ends that are suitable for the racks for better heat transfer.
On the racks, note the height of 68 mm, and put the risk. The ends of the frame are warmed up with a soldering iron, and soldered in racks to the desired marks.
Hot glue fill the ends of the racks, securely fixing the frame of the vibrator in their base. Determine the position of the cable relative to the installation of the antenna, and fix it on the frame with nylon ties.
Since oxidation degrades the quality of the received signal, the frame of the reflector must be protected. With the help of an aerosol paint, this is not difficult at all.
Since the screen is made of a lattice, it is very easy to fix the finished antenna to the mast or pipe section using clamps. At the opposite end of the TV cable, we mount the standard TV connector F. We close it to the insulation with a heat shrinking sleeve, and warm it.
Twists in the TV plug connector. We connect the cable to the receiver of digital TV broadcasting or directly to the TV with a digital tuner, and enjoy free viewing of TV channels in digital quality.
Such an antenna should be placed as far as possible towards the repeater. To enhance the signal acceptance, the frame of the vibrator is supplemented with several “squares”, and the reflector grid is complicated by horizontal bends.