Recently, Huawei's HG255D has been very popular, the reason is very simple, the configuration is high, the price is very low!
Generally, the current price of Taobao is about 50 yuan for a single machine + power supply, and the machine is more than 90% new~
I bought two telecommunications machines, original and undisassembled, and 100 yuan wallet mail! Original power supply included!
Let's talk about the configuration of the machine first
384MHz CPU
16M Flash
32M RAM
Dual antenna 11N 300Mbps
The most important thing is that you can brush OPEN-WRT, DD-WRT, and there is a USB port that can mount a high-power network card~
Some merchants can help you change to 64M memory, dual SMA antenna, priced at about 100 yuan! But for DIY, this route is highly playable, and of course you have to do it yourself to have fun! Hehe!
After starting the machine, according to the online tutorial, a non-disassembled telecom original U-BOOT is flashed into the OPEN-WRT 0508 version! Another disassembly, use the TTL line to brush the latest revised version of U-BOOT, and then flash into the 20120828 version of OPEN-WRT! There are many flashing tutorials on the Internet, which is not the focus of today!
What's the point!
It is a signal problem of suffering!
The main reason why this one will be so cheap is because of the positioning of this machine by telecommunications.
The shell of the machine is very large, and it says "low-end router"! So it is streamlined with materials!
A bad antenna is what hurts the HG255D, and it is also a not perfect place! The antenna of the original belt is just two copper platinum on board! It's really economical, so there is definitely no good signal!
To improve the signal, the antenna must be modified!
There are two reforms that are popular on the Internet.
A direct connection from the wireless amplifier chip when it is connected!
The other is to still use the capacitor banks of the original circuit, and lead the antenna from the end of these capacitor banks! Both solutions require a chip capacitor!
I have compared many such articles on the Internet, and my head is big~ I don't know if there are few people who have successfully transformed, or if some people say that there is not much improvement after the change, so they don't change! Anyway, it's just looking around, and there is no specific and useful statement! So I tried it myself!
The practice of retaining the original circuit requires soldering a feeder called a TP contact. Because the TP core point is too thin, my welding skills are limited, so I choose the first option! Simple and straightforward!
Therefore, this article is about comparing the effect of the antenna after the amplifier chip, and how about other modifications, I will not make an evaluation!
All is for reference only! The PCB of HG255D is very bad, the transformation risk is only a few dozen yuan, and it can be afforded!
Essential tools for retrofitting
Electric soldering iron, it is best to use 936 adjustable temperature~
Solder fine-dotted
Rosin is the best paste ~ When taking the capacitor, you can moisten it a little first
Tweezers, finer, because the capacitance is only 1/10 the size of a grain of rice!
Silk knife
SMA head with antenna ~ I disassembled a pair of 3dB from an early D-LINK 625
Renovation diagram
The first capacitor of the amplifier chip leads out of the pin, which is originally in C363, and it is necessary to turn to C337 and disconnect the original onboard antenna circuit!
Remove the gray feeder from the backplate
There is a soldering technique for turning capacitors, because the capacitor is too small, too hard will make the welding part of the capacitor peel and scrap, so you can stain the tip of the soldering iron, cover the small capacitor as a whole, let the solder beads wipe back and forth on the capacitor, and then the capacitor will melt and wrap in the tin droplet, quickly throw the tin on the paper, and then solder the capacitor, and then put the pad on the soldering pad after the treatment is clean. This success rate is very high! Both of us turned like this~ Both succeeded! If you accidentally lose it and pop off the capacitor, you can remove one from the disconnected circuit at the back to make up for it!
Weld well, be careful with the wire management, and then put it back!
Next is the comparative test
There are three routes
A TP LINK WR541G+, with band domain expansion function, that is to say, the signal is stronger than the ordinary routing signal on the market, for a single antenna 5dB! A HG255D with 0508 firmware without modification
The other is that we changed the antenna and flashed the 0828 firmware!
Test environment
TP LINK route is always placed unchanged, and the antenna is changed and the antenna is changed and the antenna is changed for testing!
The test scheme is
A, Comparison of the changed antenna and the unmodified antenna routing to receive TP LINK signals!
Changed the antenna to receive a TP signal to 74%
It is best to change the antenna to receive 77% of the TP signal, and it is more stable
The unmodified antenna receives a TP signal of 54%, jumping between 48% and 57%, and the signal is about 50% more ~ test 1 hour result ~
B, the change antenna receives the signal of the unchanged antenna, and the DreamBox11010 is the signal sent by the unchanged antenna placed in the living room!
C, the unchanged antenna receives the modified antenna signal, at this time, the signal of the unchanged antenna receiving TP jumps to 68%, ~ untrustworthy ~ DreamBox places the living room signal for the modified antenna route!
This renovation uses a 3dB antenna, and many of the online transformations use more than 5dB, and I don't know what the signal is, I think it should be better in principle~
To sum up
In view of so many transformation plans on the Internet, the transformation plan adopted this time is still more obvious than the original on-board antenna! If you think that such a renovation makes no sense to increase by more than 20 dB, then there is nothing to say!
However, it may be that the chip itself is not powerful enough, and when the two HG255Ds are connected to each other, the signal is not as good as when it is even TP~ This is undeniable!
Life is about tossing, I hope you can also enjoy it!
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Posted on 12/11/2014 12:49:22 PM
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