A lot of people make antennas from regular coaxial cable for the new DVB-T/T2 digital television. Basically, these three designs below are especially popular. Let's collect all three copies and check which antenna is the most sensitive among those presented.
A few calculations to get it right
So, the first thing you need to do is visit the site - map.rtrs.rf.
Enter your locality in the search bar. Then look for the closest tower to your location. We left-click on this tower and a plate appears with the frequencies of the air packets.
We broadcast two packages of digital channels: RTRS-1 and RTRS-2, 10 channels each. We look at the frequencies and in order to receive both of these packets, you need to take the middle between these frequencies. For example, if the first packet has a broadcast frequency of 700 MHz, and the second 500 MHz, then choose the middle - 600 MHz. Nothing complicated.
We have learned to determine the required frequency, now we need to find the wavelength.It is calculated using the formula:
Wavelength = Speed of light / frequency.
The speed of light is 300 mm/s. Divide this value by the frequency:
300 / 582 = 0,52
That is, the wavelength for a frequency of 582 MHz is 0.52 meters. This is the value we will need to make the antenna. The middle of my gap between the packets, you calculate your length.
First DIY antenna: whip
This is definitely the simplest antenna. Essentially it is a piece of wire, 1/4 wavelength long.
We take a piece of cable and protect its end under the plug.
We put on and screw the plug.
Remove the insulation from the piece.
Then we remove the shielded layer. We bend it to the transition and use a ruler to measure 12.8 cm (1/4 wavelength) and cut off the excess.
The antenna is ready! You can insert it into your TV or set-top box and use it. (Another option is here - https://enn.washerhouse.com/4764-samaja-prostaja-antenna-dlja-cifrovogo-tv.html)
Second antenna option for DVB-T/T2: Lavalier
It's not difficult to do either. We expose the cable on one side at a distance of approximately 5 cm. We remove the top insulation and insulation from the inner core.
We connect and twist the shielded layer with the core.
Next, we measure 52 cm from the beginning of this connection and remove the insulation to about 0.5 cm of the screen (you can first put on heat shrink).
We close the exposed end to this cut by twisting the core onto it.
Exactly in the center we remove a centimeter layer of insulation with a shielded layer.
This can be done conveniently with a stationery knife. The plug was screwed in advance. Now you can use the antenna (A similar option is here - https://enn.washerhouse.com/3978-antenna-iz-kabelya-dlya-cifrovogo-tv-za-5-minut.html).
The third antenna is similar to the second one: lavalier
This antenna is similar to the previous one, with the exception that there is no centimeter cutout in the center.
And the connection goes only to the central core without a screen.
Which antenna to choose for digital television?
Let's conduct tests and determine which antenna has the best sensitivity.
As a result, this is how the stars were positioned:
So the conclusion is simple: if the television tower is located in close proximity to you, then a simple whip antenna will do, which will hide behind the TV and will not disturb anyone.
Well, if the tower is still far away, then feel free to do the second option. In terms of its sensitivity, it leaves behind even purchased antennas with an amplifier! Don't believe me? Then read the reviews here - https://enn.washerhouse.com/3978-antenna-iz-kabelya-dlya-cifrovogo-tv-za-5-minut.html#comment
