Teclast X98 plus II wifi modding and experiments

[Golden]

I bought my X98 plus II just before the reviews came out and the wifi issues became clear. Had I known, I would have stuck with version I.
Since then I have followed this forum and tinkered with the wifi.
I have learned several things:

• An external wifi dongle works a treat in Windows, but it would take a genius to get it working in Android
• The X98 plus II is remarkably robust for taking apart and putting back together. I must have opened it several dozen times, still no clips or notches broken
• There is sufficient space inside the tablet for different or more wifi antennas and their cables

Some other things regarding the wifi:

• The factory wifi antenna is not bad at all (compared to others I’ve soldered in place)
• The metal back of the tablet hugely impairs wifi performance. Taking it off increases wifi signal by at least +10 dB (I have actually routed a wifi antenna through one of the speaker ports to confirm)
• Compared to other devices, the signal strength is equal or better
• However, the data throughput at poorer signal strengths is worse. This can be as result of signal quality or as result of the wifi radio / chipset

An example of the last point is: when I lay the tablet and my old smartphone side by side, the tablet gets -70 dB signal strength and the phone -80 dB. However, the tablet’s data throughput is max 50KB/s whilst my phone still does 800KB/s (roughly 6Mb/s broadband).
I have concluded that until a software fix is issued for the wifi chipset, the only improvement possible is to ensure the signal strength that the tablet sees is as high as possble. I’m no wifi expert, but for now I have 3 wifi antennas in parallel soldered to the wifi connection on the motherboard. One sits where the original was (which eventually broke when I was experimenting with it), one between the speakers at the bottom and one on the left of the tablet, away from the screen electronics.
So far this configuration is the most reliable. Just a hint if you wish to do something similar: soldering these very thin wifi coax cables can easily melt the plastic around the core, resulting in shorting the antenna and ground, leaving you with very poor signal.

Good luck and thanks for reading.

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[abdul aman]

thanks. but when will we get the software fix, will we ever get?

 

[Max Barfuß]

Hi Golden, thx for your experience and your tips. If I do so too do I need special wire or can I reach better performane with usual isolated copper wire.

Thx again

Max

[Andy]

Golden, which version of Teclast X98 plus II did you investigate? Maybe C2D4 is somewhat different from C2D6 in the WiFi part?

[Veaceslav]

Hello, I did my own experiments about antenna, and you can read about them here:

http://forum.xda-developers.com/x98-air/help/hardware-mod-improving-wifi-connection-t3469374

 

if you didn’t put antenna behind the metal cover, you could get better wi-fi speeds. The good place is on top, where the plastic stripe is.

 

[Max Barfuß]

Thx Veaceslav this will help me a lot for my own tries ???

[Golden]

Andy, sorry, forgot to mention. C2D4 is my model.

Vaeceslav, that’s a really good idea. I was wondering how to have an external antenna which is aesthetically acceptable!

[Veaceslav]

I wanted to point out that this is a pure hardware issue. The fact that you see good signal displayed in Android that doesn’t mean that the connection is good.

The reason is because the displayed signal strength is the received one and the router transmit power is way more powerful compared to any mobile device’s transmit power. The problem appears when you have a strong transmitter(router) and weak transmitter(our tablet):

1. router transmit, but the tablet’s response doesn’t reach back the router, and the router retransmit the same thing over and over again
2. tablet request something, but the router doesn’t receive it

If our tablet’s antenna does not amplify enough, you get drops. The only software fix is to configure the driver to make the chip set the transmit power to maximum-> you will see a hit on battery life.

[Author]

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