Bored to make a DTMB antenna

Became the first original article that was sent out, and the small things tossed in the last half year were written one after another. Previously he had been writing anonymously and he couldn't make any rewards. He always lost a lot of gold coins.

There is often time for tossing. The last article was December 2015, and it took a long time for 2016. When the DTMB was at the time of the Mi-Election, it wasn’t easy for the buddy to wait until the end of the eight-year term of the Okuyama Sea, thinking that she could finally become the first woman and the first female president, and everyone knew what followed.

In fact, they have a good relationship with me. Our days are still like that. Tossed life can not stop, often on the Aunt station to buy buy.

Cable TV has already stopped for a long time, replaced by the Google family bucket 6.0 pure Android box ease of use, coincides with the leadership of the baby tour, cleaning up the tattered found that the original TV with an extension cord and a protective box there is a magnetic ring (Matsushita plasma ingredients Foot, buy back a bunch of things you can't use.) Shenzhen has terrestrial digital television. The local cmmb and China Mobile cooperated to make money each month (in the 3G era, they had 5 yuan per mobile phone per month, and the equipment cost of the cmmb chip produced by the Shenzhen electronics factory was all collected by them. The provinces of cmmb stare at and demand that all provinces in the country share Shenzhen. The result is a mess of big pots of rice. No one will willing to go to development. They are afraid that others will collect peaches. The result has been met with several layman's commandments. As soon as 4G is released, it will be a big death. We will take a look at the country's previous investment in cmmb. Oh, the legacy transmission stations are now used for DTMB.

Above is the connection on the wiki. Here is an explanation:

DTMB (GB, full name Digital Terrestrial Multimedia Broadcast, ie, terrestrial digital multimedia broadcasting), formerly known as DMB-T/H (Digital Multimedia Broadcast-Terrestrial/Handheld), is a digital broadcasting of digital images in China. Standards: The People's Republic of China formulates standards concerning digital television and mobile digital broadcasting. The system will serve half of China's television audience, especially in suburban and rural areas. DTMB is currently used in mainland China, Hong Kong, Macau and Cuba. DTMB has multiple subcarriers (referred to as "multi-carrier") and a single subcarrier (referred to as "single carrier") two modes [1]; Hong Kong and Macao use multi-carrier mode, both in China are used. In addition, DTMB has only established a data transmission standard for MPEG-TS, but does not specify a broadcast streaming encoding system. For example, in Hong Kong, the synchronized broadcasting channel and the new channel used MPEG-2 Part 2 and H.264 as the broadcasting image coding before October 28, 2012. However, all digital broadcasting channels now use H.264 broadcasting; The encoding can be selected from AC3 and MP2. [2] In mainland China, AVS and its upgraded version of AVS+ are adopted as the video encoding standard, but there are also those using MPEG-2 [3]. From September to November 2012, RTHK tested four new technologies with Asian Television and Television Broadcasts Limited, including 3D TV transmission, PN420 transmission, and DTMB-A and E-DTMB [4].

Prepare to try to buy an antenna on Taobao, to extend the first plug in the back of the TV, just put the TV that did a wire gadget, do not know what to plug the antenna hole.

As for the wire in the photo, the result received 7 sets.......the thief knew clearly that the signal 9...intensity was about 5, the digital signal, or received, or did not have or mosaic, the signal has a 3 to 4 can see. But ..... Internet TV can not see the Hong Kong station, there is a wood.

The Yagi antenna can be found on Taobao

As long as the general, some people can see the balcony.

Hanging outside the door, the price is between a dozen and a hundred, see the variety of comments.

Some articles also say that to buy a 586 project vibrator, indoor will be able to receive, price 20 to 50.

There are also known as fly swatter, which is much larger and more complex. It is said that the effect is good and the price is about 4 times that of 8 wood.

In view of the foregoing, take the N-segment with the steel wire, or make an antenna yourself. (In the process of pursuing cost-effectiveness, cocoon often chooses difficulties, and then goes to a more complicated path. In fact, the last time and money are taken in. This is the syndrome of qiong. If there is free time, then write another copy of the walled city. Solar laptop power supply system ... ... ... are the cost of tears conversion in this lifetime sun will not come back, double 30W parallel Philips Polycrystalline, if you count the Walled City housing prices, this board cost is really sin, ah, capacity I slowly

Referring to several forums, the most easily realized are diamond-shaped antennas, which have a wide range of uses. Whether they are magnifying wifi or receiving DTMB, the difference lies in the length of the antenna.

There are two diamonds or four, and the effect of the four is better. The figure above is the same, regardless of size.

The length of the side is calculated based on the frequency that needs to be received, first referring to the local channel distribution in Shenzhen.

This ATV is still in the picture, now when it is referenced, the station signal is in front of the signal frequency, 602MHz that four stations because of the failure of the ATV failed, the length of the antenna on the basis of this calculation, the fixed length of the side is only the corresponding frequency effect Best, not something else, it's just a matter of sensitivity.

If the length of the side is different from one place to another, for example, if the channel to be received is distributed in the range of 500 to 600, then the side length is calculated by taking the intermediate frequency 550.

Light speed/frequency*coefficient=wavelength, coefficient is 0.95~0.97, light speed is 300,000 kilometers or 299,792 kilometers, I take about 620MHz, (299.792/620)*0.97=0.469 meters, wavelength 1/4 is about equal to 11.7cm , take 12cm good size.

The first use of stainless steel wire bent a simple double diamond, the effect is poor, first, the material is not appropriate, it is best to use copper, the second is a casual amount, all sizes are not accurate, flatness is not good, and that 10cm Wire is an effect, it looks too ugly to go on.

The 2.0 version last year bought the remaining copper tubes of the air-conditioner. The section was large and the tubes were thick. After folding, the copper sheets were soldered with contacts.

The copper pipe is also not easy to bend. In fact, careful measurements are taken. The length is between 11.5 and 12.5. It is not accurate. It cannot stand up to the material and the effect is very strong.

The original small Japanese extension cord, cortex core.

The shield is rolled up and soldered to the two poles of the antenna together with the copper core. The finished product is as follows:

Twist with two screws to facilitate the replacement of the next broken, the other side bought an ordinary white antenna in Taobao, a male and a female, most of 5 meters 10 yuan. It can be fixed to the balcony with a strap. Originally put in the room can also be used, rthk's 802 paragraph can only be two sets, put the balcony can be three full. The Shenzhen antenna must be placed vertically. The specific principle is too long. The meaning of the forum is related to the modulation of the emission signal. Everybody performs a search and there may be differences in each area.

In recent years, according to national regulations, terrestrial digital television receivers have to be built in the national regulations, and the menus are different. After the antennas are connected, they are automatically searched.

The first to receive is the 562's two HD local channels.

The above shows about 9 minutes. In fact, 3 to 4 minutes is fine. There are at most 29 stations. The above figure is more than 800 MHz for rthk, and it is far too far from the 600 or so of my antenna. The effect is not very good, but As I said before, digital signals, more than 4 can all be seen, are mp4 encoded.

This is the latest Shenzhen 19 local channel frequency table, the Central 1 to see the Spring Festival Evening is no longer afraid of the network card (although I do not see, the elderly at home still like), the Central 5 + is not HD Caton, there are 9 in Hong Kong there In March 17th, there will be another 10 English-language stations.

This picture is the first time I saw high-definition rthk (equivalent to CCTV in Hong Kong, NHK in Japan, which was financed by the government but free to edit channels). The small print is very clear and shocking. I don't know what happened after the Aunt station was compressed. When Shi Xi was still full of energy, there was nothing...

This is the effect of indoor collection, 28 stations, and several more after hanging the balcony.

The HD Jade platform supports multiple audio tracks and multiple subtitles, Cantonese/English, superb subtitles, and the channels on the other side are basically all-in-one, as well as Korean/Cantonese and Shenzhen channels.

Similar to Internet TV, there are program schedules and program schedules for the coming week. You can schedule reminders via TV.

The news station on the other side, the style is the following important subtitles. The channels of Hong Kong that can be received so far are as follows. We look at the channel on the other side with a critical eye. After all, it is also a part of the motherland:

Radio Television Hong Kong

RTHK TV 31 RTHK TV 31, 32 RTHK TV 32, 33 China World TV Network Record Channel

Wireless TV

81 Jade Terrace, 82 J2, 83 Interactive News, 84 Pearl Taiwan, 85 J585 HD Jade

Hong Kong Television Entertainment

96 ViuTVsix (March 2017), 99 ViuTV

See if you are eager to try here, regardless of self-control or Taobao, foreign friends can first move. Friends of Zhaidu, etc., it's time to pour cold water.

This is the distribution of Shenzhen's current launching station. There are basically no dead ends. When cmmb was used as old money, they used an antenna in an underground parking lot. Why did you want to do so? Is it allocated to all provinces in the country? However, if you look at a Shenzhen station, the Android box is just fine. Why toss it out, mainly to prepare for criticism of capitalism on the other side.

This is the distribution of three transmitting stations that can be transmitted from Hong Kong. There are six large transmitting stations and numerous small stations. There is no problem for the signals of the Zhaidu, Nanshan, Futian and Luohu facing the transmission tower. . TV has been there early, also recently moved to the high-level direction in the face of the sea only have the mind to engage DTMB, the antenna's angle is very important, to find the strongest signal must be fixed to make a mark.

Before Xiao Bian hit it back, it must be said that it has advantages and disadvantages, because it is not a finished product. Pure DIY, general speaking, the difficulty of antenna production is very low, there are too many online posts, everybody has a look, there is this, this is legal, the Olympic Year Huimin project at that time. Unlike early Shenzhen, it did not give residents an antenna on the roof of the building. It was to promote cable television. The head of the xcb ordered was still the former leader, and he wouldn't look at the station anyway. Basically, there are no shortcomings. If you have a good antenna, you can say it. The television station opposite the station was supposed to provide the benefits and broaden the horizons. Until now, it is believed that the level of translation of several foreign languages ​​at Jade Terrace is only high for the average student, the early TOP gear, the bbc, and so on.

There is no time to look at the antenna. The old man in the family does not like Cantonese. Hey, he has learned Cantonese for 2 months.

If you have any doubts, you can leave a comment and try to answer it.

This time on these, hope lazy cancer and save, find time to write something else.