» Antennas »Antenna DVB-T2 for 100 rubles

Antenna DVB-T2 for 100 rubles

Antenna DVB-T2 for 100 rubles

In connection with the transition of domestic television broadcasting to digital, friends and even strangers began to turn to me with a request to install a digital set-top box.

You don’t need to buy and connect the set-top box to a TV, a lot of instructions come with it, where it is written in black and white and even in the pictures shows what and how to do it.

But with antennas it is not so simple. If in rural areas and outside the city for the reception of digital TV I definitely use only a good external antenna with an amplifier, then in the city the ability to install an external antenna is not always there. I wanted to buy a simple indoor antenna, but in the nearest stores there were no indoor antennas for digital TV at an affordable price. I did not want to wait until they sent from the alibaba ...

Therefore, I had to come up with a small indoor antenna, designed to receive digital TV signals.

Of course, I didn’t come up with anything fundamentally new, I just remember that once I saw something similar on the car of a trucker, he used a similar antenna to receive regular TV, but only during parking.

This antenna was based on a regular Pistolkors loop vibrator from a piece of copper wire, and the SWA antenna amplifier board, sold in almost all electronic stores.

I simply determine the vibrator size: we substitute the channel frequency of digital multiplexes (we have 505 MHz and 650 MHz) in the following formula: 300: f = x, where X is the length of the vibrator in meters and f is the frequency in megahertz. For our area, it turned out 0.59 m and 0.46 m. ​​I chose a certain average value - about 50 cm.



SWA antenna amplifier boards are also different, the following numbers are best suited for our purpose: (in order of deterioration in gain quality) 9001, 9501, 6000, 3501, 2000, 9999. SWA boards with other numbers will not work, they are designed for different frequencies and have a weaker gain.

We select a piece of copper or aluminum (with aluminum the signal will be weaker) wires with a diameter of 2 ... 4 mm twice as long as calculated by the formula. The thicker the wire, the better. You can even use a copper pipe from the brake system. We bend this piece of wire as shown in the figure.

We mark the middle on it, and cut off too much, leaving small bends for contacts. If a tube is used, then flatten the ends of the tube with a hammer, and then drill holes for screws in them.

We clean the wire and bend the ends, forming from them loops for screws.We attach the vibrator to the amplifier board with M3 screws with nuts and washers. The length of the vibrator from edge to edge I got exactly 50 cm.

We connect the antenna wire of the required length to the amplifier. At the end of the antenna wire, install a plug based on the F - connector.

We connect the antenna to the set-top box and go to the menu. Select the ANTENNA POWER section and turn on the power of the amplifier. Then go to the MANUAL SEARCH section and select channel 43. We are trying to catch the signal, orienting the antenna perpendicular to the telecentre. The prefix does not display the signal level immediately, but with a delay of 2-3 seconds, so there is no need to rush.

After we caught the signal on a higher frequency multiplex, select 25 channel in the menu and achieve a good level on the low frequency multiplex.




After the best position of the antenna in the room is found, we fix it on the wall, for example, or on a bookshelf (in my apartment the antenna just lies behind the picture) and go to the AUTO SEARCH menu section. After an automatic search, the prefix remembers all the channels and is ready to work.

Happy viewing!
9.4
9.5
9.1

Add a comment

    • smilesmilesxaxaokdontknowyahoonea
      bossscratchfoolyesyes-yesaggressivesecret
      sorrydancedance2dance3pardonhelpdrinks
      stopfriendsgoodgoodgoodwhistleswoontongue
      smokeclappingcraydeclarederisivedon-t_mentiondownload
      heatirefullaugh1mdameetingmoskingnegative
      not_ipopcornpunishreadscarescaressearch
      tauntthank_youthisto_clueumnikacuteagree
      badbeeeblack_eyeblum3blushboastboredom
      censoredpleasantrysecret2threatenvictoryyusun_bespectacled
      shokrespektlolprevedwelcomekrutoyya_za
      ya_dobryihelperne_huliganne_othodifludbanclose
34 commentary
Anon
You do not have the coordination of the resistances of the dipole and amplifier of 75 and 300 ohms, you had to exclude the transformer from the amplifier so that the resistance was the same, that is, 75 ohms
Not 4, but 2 times. The antenna span should be approximately half the wavelength.
The amplifier is intended only to compensate for cable losses.
Guest Sergey
The vibrator size must be made at least 4 times smaller. Specified in the photo is certainly not 100 rubles. And the power of the amplifier from where and how much it costs. In general, crap is complete.
Guest Sergey
The calculation of the size of the loop (loop !!!) vibrator is fundamentally wrong, but with the amplifier, of course, it will show anything.
only Harchenko’s antenna - google. The rest is much worse.
Guest Sergey
It is unlikely .. If there is any structure on the way, then most likely the antenna will catch the reflected signal, and this is fraught with loss ...
Guest Vladimir
Something is wrong with your arithmetic ... First, they cut a piece of wire 1 meter long, then bent it into a loop (roughly speaking - in half) and got a loop length = 50 cm ... But at turning radii the wire is consumed (at least 4 -5 cm). Then you bend the ends and bite off the excess wire ... I don’t know how much? ... And after all this, you still have a vibrator loop with a total length (as I understand it) of exactly 50 cm ... ??? How from 1 meter, taking into account all the minuses, did you achieve this size ??? Are you Gooddini?
Do you have it in Belarus?
Prices - it seems, not Belarusian!))))
56 rubles + 30 rubles + 15p = 101 rubles ... It’s a bit too much to give everything $ 50 ... The antenna is ready, I think it’s cheaper.))) $ 50 is the price, rather, of a satellite dish.)) )
Wah, what a good person.
Taki copper wire
Lizergild
I also wanted to write and the letters disappeared
that digital television is accepted even on a steel member from sex shop
verb that he was in direct line of sight of Ostankino and not on minus the ground floor
I have finished.
Tungsten
Do you have it in Belarus?
Guest Alexander
The board on the market costs a penny, the antenna works great, only you need to turn on the antenna power in the console!
Guest Alexander
beer cans and everything will be ok, without any abstruse canoes n ** th there to rack their brains.
Author
I fully agree with you, Igor. It’s the hardened woman who’s doing it when it’s really far or difficult to catch something. And what is described in the article is in such a hurry. The TV tower from the installation site is two kilometers from the window is visible. I didn’t expect such an interest in my design. 73!
Guest Ilya
Are you banned in Google? Congratulations
Guest Ilya
The best conductor is not gold, but silver. So from the silvered wire the best antennas then.
Silvering or gilding of antenna elements is everything from the evil one

Made a digital antenna of cucumber and horseradish. And what difference does what to make - in our wilderness still does not show a damn!
smile
That's right, just not the spin, but the skin effect from the English Skin - Skin.
You asked an abstract question that cannot be answered. See below comment from Andrey V. Semenov.
I would add:
4. The terrain between the place of reception and the television center.
5. The attenuation of the signal in the antenna cable and the presence of an antenna amplifier to compensate for this attenuation.
I don’t know how it is built into the TV, but the receivers in the settings have such an item “antenna power”. On it you need to put a checkmark "on".
Guest Nikolay
The loop vibrator is half the wavelength, 25 cm, not 50. And the boards 777, 555, f-103 work fine from 5 volts of the antenna power of the digital set-top box.
Emelyan
And how is the supply voltage connected to this amplifier, or can it work like that?
Andrey V. Semenov
The main factors providing high-quality reception of any digital or analog signal are:
1. The gain of the antenna;
2. The height of the antenna.
3. The distance to the TV center and the power of its transmitter.
Silvering or gilding of the antenna elements is all from the evil one (the wrong frequencies are used in digital TV). By the way, "Chinese consumer goods" is not so bad for domestic purposes. You can buy a simple antenna gilded, install it behind a concrete or iron wall (roof) and scold the manufacturer on what the light stands. Don't be fooled by ads from sellers promising a Japanese antenna that receives 190 channels. Does your TV know how to receive so many channels ??? Consult a trusted specialist. Good luck and remember where the free cheese is!
Author
Good day, Sergey. No, most likely it will not. I tried this and several other antennas in a friend’s apartment on the ground floor of a brick house about 5 km from the transmission center. It turned out four walls between us. Useless. I had to connect the cable. Only a few analog channels caught, and that’s it.
Guest Igor
I’m a radio amateur, over 40 years on the air, I recommend the antenna of Harchenko, with a side of a square of 13.5 cm, to be the best antenna for receiving digital channels. You can watch this antenna and its description on the Internet. Very simple and easily repeatable antenna. No need for headaches and problems from plumbers ,, about silver and Japanese antennas.
Quote: Guest Ivan
The concept of "Q factor" exists not only in RF technology, it means the ratio between the input signal and the losses in the device.

Yes, just not a ratio, but a ratio. And not the input signal, but the reactance of the coil (X = 2 * pi * f) to the loss resistance. Which, in turn, is practically impossible to measure. It very much depends on the material of the circuit (coil), its physical configuration, the relative position of the turns, etc.
For broadband antennas, high quality factor is not very good.The quality factor should be such that the extreme frequencies of the received range are at least -3 dB on the curve of the frequency response of the circuit. In this case, the antenna.
Guest Ivan
The concept of "Q factor" exists not only in RF technology, it means the ratio between the input signal and the losses in the device. Any circuit on the CB range, and on other ranges, too, has a quality factor.
Guest Sergey
Good afternoon! And will there be a signal in the sleeping area on the ground floor with such an antenna?
Author
The SWA fee costs 56 rubles, 30 rubles for the antenna plug, the remaining 15 rubles for the wire. I won’t say the address of the store, otherwise they’ll think that it’s an advertisement.
Author
In high-frequency circuitry there is such a concept of "quality factor". The higher the conductivity of the material, the higher the quality factor and the less loss. At frequencies above 500 MHz, a “spin” takes place - an effect when an electric current flows only along the surface of a conductor. The best option would be to make antennas of gold-plated wire. Such antennas were in the first models of cell phones. In modern conditions, silver-plated copper wire is used in receivers at high and ultrahigh frequencies. In the army, for example, I worked with 470 MHz radio relay antennas that were silver plated.
As for Chinese consumer goods, their engineers apparently did not teach high-frequency circuitry ...
And what did not announce the price of the board? And exactly sold in "electronic" stores?
with aluminum the signal will be weaker

Why?

We advise you to read:

Hand it for the smartphone ...