Review of three popular low-cost digital satellite receivers (Part 1)

Just a few years ago, the mention of digital machines was almost synonymous with high technology, high price, and high-end. At that time, the price of a NOKIA 9500S was more than 10,000 yuan. However, in these few years, especially in the past year, the price of digital machines has fallen to the level of one-twentieth.

Among the high-end digital machines, TOSHIBA's 1000-type FTA digital machine has won the recognition and favor of users for its outstanding picture quality, sound quality and stable performance, especially high-end users and many large hotels and hotels. Momentum not used by TOSHIBA digital machines. The machine has been produced in Shanghai, China. However, the strange thing is that a few days ago, a TV station in Shanghai came to the local area and bought the last three machines in the hands of a local distributor of TOSHIBA digital machines. Why did the TV station move closer and farther, and travelled thousands of miles to the northeast to buy 3 TOSHIBA digital machines? Originally affected by the low price of the Chinese digital machine market, Shanghai Jinzhi's TOSHIBA digital machine has been completely discontinued. The station was finally found here after searching the national market. Similarly, at the end of last year, a Korean digital machine manufacturer was planning to build a digital machine in the Northeast. During the inspection period, it was decided to first put a batch of products into the Northeast market for trial sales. The manufacturer once took a prototype to ask the author to do the evaluation. Whether it is the sound quality or the function and operation, it is satisfactory, and the performance is very good. However, after half a year of market trial sales, it was necessary to accept the harsh fact that the price was cleared from the initial 1,500 yuan to the last 600 yuan, and few people liked it. It is also because of the price factor that the world famous brand NOKIA ’s FTA machine has not been seen in the Chinese market. In fact, the machine has not been discontinued, but because there is no demand for the high-priced digital machine in the mainland, there is no dealer ordering and distribution. Even some digital machines in Taiwan in our country have been completely removed from the mainland market in the price war. The low-priced digital machines produced by the mainland have completely occupied the digital machine market in China. Even in Myanmar, Indonesia and other places, Taiwan and South Korea The product was completely defeated. As the price of digital machines has been reduced to a low level, it has also brought some quality and service problems. Some have high repair rates and some have reduced after-sales service quality. The author always believes that the price reduction is based on the premise of ensuring the quality and service of the product. If you can't do this, the price will be the lowest, but it is just some waste that cannot be used normally, and no one will want it if it is cheap.

The three kinds of digital machines introduced by the author here are all common and low-priced, practical and popular products currently on the market, and they are guaranteed in quality. Heikewei HIC-2000H digital satellite receiver The machine is small and compact, the front panel is 35.5 cm long and 6.5 cm high. On the left side of the panel is the Hiwayay trademark, and below the trademark is the switch. In the middle is the display screen. On the left of the display screen is a LOCK display small red light. When the small red light is on, it means the signal is locked. The IR on the right is the remote control receiving window. The red number in the middle shows the number of channels. The basic operation keys of the machine are on the right side of the panel, and a circle is formed by the up, down, left and right keys, and the OK key is at the center of this circle. On the left and right sides below this circle are the main menu key and the left and right channel switching keys, respectively. In this way, the user can also operate through the panel without a remote control. On the back panel, the intermediate frequency input port adopts the popular one-in-one-out structure, with a set of S terminal and AV output. The aircraft has recently added a new set of RS232 upgrade interfaces. I often test the latest software of various versions for many digital machines including this machine. Since the original machine does not have this upgrade interface, I have to solder the circuit board for jumper every time I upgrade, which is very inconvenient . Now with this interface, I feel much more convenient. Regarding the addition of the RS232 interface, there is a short story here. The original Heikeway digital machine did not have the RS232 interface. Many manufacturers have been confused about the long-term strategy of Heikewei to keep the price low. A factory sent a person to the author at the beginning of this year to understand the situation. After fully understanding the internal circuit and external output structure of the machine, the person in charge called the factory in person and instructed the relevant personnel to immediately remove the RS232 interface on the back panel of the factory's digital machine to further reduce costs. But shortly after the incident, the new version of the Heikewei machine added the interface. Later, the author specifically consulted the company's General Manager Zhou on this matter. Chief Executive Zhou believes that the price of a product in the initial stage of entering the market is very important, and manufacturers must do everything possible to control costs. But when the market opens, the functions of the products must be constantly improved. On the other hand, while the aircraft is doing the domestic market, it is still exploring overseas markets, and overseas markets have demand for this function. Now the domestic market of the aircraft is also forming a scale. The same version of domestic and overseas products is also the trend . The success of Heikewei is inseparable from their good grasp and operation of the market. The practice of some manufacturers in this respect is very worth pondering.

The Heikeway digital machine uses the most popular Fujitsu solution, which is also the solution used by many low-priced digital machines. But a good digital machine has spent a lot of energy on software development. Because Heckway has also made great efforts in software development, the operation of this machine is much improved compared with other digital machines that use the same scheme, such as the parameter input speed of this machine is more than some other schemes. It ’s fast, so it has formed some of its own unique style.

The following is the main menu of this unit. In the two submenus of "TV program" and "Broadcast program", the TV or radio channels stored by the digital machine are arranged. After entering the submenu, you can use the up and down arrow keys on the remote control to move the cursor to the name of the program channel you want to watch, and press the OK button to watch or listen to the corresponding program. If no signal is found, no satellite signal is displayed on the screen. The "Program Settings" submenu in the main menu contains most of the basic operating functions of this unit. The menu is as follows: "Add Program". In this sub-menu, set the parameters such as downlink frequency, symbol rate, polarization mode, 22K switch, DiSEQC switch, and LO frequency. The lower part of the sub-menu of this layer displays the corresponding The percentage of signal strength and signal quality, if the signal is received or locked, the word "signal" appears in the bottom signal state. At this time, press OK to search for programs. For enthusiasts who like to seek stars, using this machine to find stars is also a good choice. After the parameters are input, the response speed of the signal status bar is still relatively fast in the ordinary digital machine. The numerical response of the signal quality of the aircraft is also very sensitive, and it is better to fine-tune the satellite signal. "Modify the local oscillator frequency", in various digital machines, the local oscillator frequency is relatively fixed. This function actually modifies the default value of the LO frequency column in the "Add Program" submenu. "Program parameter setting", the function of this menu is equivalent to the editing function in some digital machines, where the program name can be modified, and the local oscillator frequency, downlink frequency, symbol rate, polarization mode, DiSEQC switch, 22K switch, etc. The parameters are modified. However, unlike the general editing menu, the PID code can also be modified here. In fact, this is also the menu option for the machine to increase the PID code. "Auto search", the machine has preset parameters of more than ten satellites and hundreds of channels. However, too many storage channels actually bring a lot of inconvenience to channel changing during actual viewing. If the antenna orientation has been fixed, the machine will automatically search for the factory-set program after powering on. If it can be locked, it will be automatically added to the program list, and the remaining unsearched programs will be automatically deleted, which will bring great convenience to daily use in the future. The "program editing" menu in the main menu is a very popular function. In this layer of sub-menu, you can easily realize the arbitrary movement and position arrangement of each channel, and arbitrarily delete unnecessary or unfavorable programs. The "Signal Strength" submenu in the main menu can display the signal strength and quality of the current channel, so that the user can adjust the antenna status and maintain the best reception quality. Although related parameters are also listed in this menu, they cannot be edited or modified. By operating the "default settings" submenu in the main menu, the unit can be restored to the state, parameters and channels preset at the factory. It is worth mentioning that the remote control of this machine is very unique. It is said that it is unique. It does not refer to its rich functions and luxurious appearance, but the design is very simple. The remote control buttons of this machine are also less than those of other digital machines. In addition to the basic operation keys such as numeric keys, MENU keys, up, down, left and right keys on each remote control, the other shortcut keys have only one SIGNAL for display Signal strength; an AUDIO, used to adjust the channel; a set of volume keys, used to adjust the volume. Unlike some digital machines that make big fuss on the remote control, the remote control of this machine is very light and thin like some low-cost VCD remote controls. As a low-cost, practical digital machine, a simple design is necessary, but if the buttons of the remote control are slightly enlarged to increase the convenience of user operations, it will be more perfect. There is also a hidden function in the shortcut keys of the remote control. If you press the OK button while watching a program, the program screen will pause and display a still picture, which is very interesting.

Now, the threshold of digital machines has not been paid much attention to by users. This is mainly due to the popularity of high-power satellites and digital programs. Originally, the author did not plan to introduce this question anymore. However, recently, with the official launch of digital programs 1, 2, 7, 10, and 11 in the central government, many people find it difficult to receive these programs in the Northeast region, and the digital signal is very weak. According to the actual test by the author, in the northeast region, when receiving digital programs from CCTV, the signal strength of the 1.8-meter Zhongwei antenna has just exceeded the threshold value, and even in rainy days, there will be rare C-band "rain attenuation" phenomenon. On the same time in Asia Pacific 1A, Xinjiang Satellite TV, which also broadcasts using MCPC, showed that the signal strength of this unit was 4% higher than that of CCTV and 11-14% higher in signal quality. Even the digital programs of the provincial stations broadcast using the SCPC method are higher than the central station except for the signal strength of the Gansu station and the central station. At present, the main user group of domestic satellite TV is rural households receiving the Asia-Pacific 1A satellite. As the digitization of the Asia-Pacific 1A accelerates, especially the digitalization of the central station, the digital machine will soon become a hot spot in the rural market. For home reception, the 1.8-meter antenna is already the limit. The 2.1-meter antenna is difficult to popularize in terms of installation, windproof, and price. On the one hand, the price of the 2.1-meter antenna basically exceeds Zhongwei 1 . More than double the 8-meter antenna. The threshold has become the key to whether the 1.8-meter Zhongwei antenna can be used to stably receive CCTV digital programs. After actual testing, the author found that the threshold of this machine is indeed very low, and the reception effect is relatively stable under the same conditions. According to the author's observation, the threshold of this machine is not very different from other machines. It is impossible to distinguish when watching strong signal programs such as Asia No. 2, but only when using 1.8 meters antenna to receive digital programs from CCTV. It can show its advantages when it is rainy.

Although the price war of digital machines is very fierce, the low price does not mean low quality. The author has always insisted on any price of products, and ensuring quality is a basic premise. Heckway has done a good job in quality control. According to the feedback from dealers and maintenance personnel, the return rate is particularly low. Especially for the power supply part, its Switching Power Supply is an AC? DC high-efficiency switching power supply composed of the second generation TOP223Y conversion module of Power Company of the United States. The feature of this module is that it integrates all the functions of the pulse width modulation (PWM) control system into a three-terminal chip, and truly realizes the monolithic integration of the switching power supply. Due to the use of COMS circuit, the power consumption of the device is significantly reduced, and the duty cycle of the pulse waveform is linearly adjusted by the current; the chip has only 3 pins, which is comparable to the three-terminal linear regulator, and can be constructed in the simplest way. Frequency flyback switching power supply; the input AC voltage range is extremely wide; the switching frequency range is 90-110kHz; the peripheral circuit is simple and efficient, suitable for large-scale production, simple operation, and low production cost; the operating temperature range reaches 0 －70 ° C. Therefore, the reliability of this power supply is very high. And according to the person in charge of the technical department of the plant, the power supply of the machine is still being improved and the performance will be more stable.

For the compatibility of this machine, the author deliberately tested the Korean programs on the two satellites of 113 degrees and 116 degrees, which are the most recognized digital machine compatibility. It can be well compatible with all Hanxing programs. it is good. As a low-priced digital machine, its performance on images and sound is also satisfactory. Especially when receiving CCTV's "Newscast" program, the studio's blue background is very pure and very cute, which is annoying to CCTV's analog programs. The noise and hiss are no longer there, the blue has a feeling of flowing down from the screen. Watching the 10 sets of the Central Committee approaching the science program, the hostess ’s facial details are very clear, and the bright colors emitted by the lipstick can more truly feel the host ’s charm. var check_allow = "/d/Api/iscantalk.html"; var add_url = '/ d / article / write /'; function CheckLogin () {now_uid = ''; var ElecfansApi_checklogin = '/ webapi / passport / checklogin'; var logout_url = "{: U ('Login / logout')}"; var logout_url = 'http://bbs.elecfans.com/member.php?mod=logging&action=logout&refer=front'; $ .get (ElecfansApi_checklogin, function (data, textStatus) {if (data! = "") {EchoLoginInfo (data); CheckEmailInfo (data); data = $ .parseJSON (data); now_uid = data.uid; / * var login_content = 'write an article