WiFi - hardware problem with antenna soldering

Hardware Mods For the MK808.
BooLE
Posts: 61
Joined: Tue Sep 25, 2012 9:41 am

WiFi - hardware problem with antenna soldering

Postby BooLE » Sat Nov 10, 2012 2:22 pm

Hi,

after several people found that their antennas in MK808 have been badly soldered, I was curious and opened the casing myself. With multimeter instrument I checked the connection between live wire and shield (ANT and GND points) and confirmed that they are in my case also in closed circuit. This means that at factory they don't know what they are doing, or just don't care when soldering antenna.

I decided to solder new antenna, that I had from my old Vodafone mobile connect card, and I did it. Results were immediately great, no more signal loss, my wifi found also APs from my neighbors (which I could never see before on MK808). I only solderer one antenna, and the other I just unsoldered. I made little modification on the casing for the cable, and now it works great.

I recommend everyone to check this if they have knowledge and instrument, and if possible at least repair bad soldering.

BooLE
Last edited by BooLE on Sun Nov 11, 2012 4:24 am, edited 1 time in total.

T68
Posts: 30
Joined: Thu Nov 08, 2012 7:21 am

Re: Sv: WiFi - hardware problem with antenna soldering

Postby T68 » Sat Nov 10, 2012 6:50 pm

Interesting! Please post some pics and a more thorough instruction on what to check and to solder.

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stelin
Posts: 37
Joined: Sat Oct 13, 2012 6:18 am

Re: WiFi - hardware problem with antenna soldering

Postby stelin » Sat Nov 10, 2012 9:46 pm

BooLE wrote:Hi,

after several people found that their antennas in MK808 have been badly soldered, I was curious and opened the casing myself. With multimeter instrument I checked the connection between live wire and shield (ANT and GND points) and confirmed that they are in my case also in closed circuit. This means that at factory they don't know what they are doing, or just don't care when soldering antenna.

I decided to solder new antenna, that I had from my old Vodafone mobile connect card, and I did it. Results were immediately great, no more signal loss, my wifi found also APs from my neighbors (which I could never see before on MK808). I only solderer one antenna, and the other I just unsoldered. I made little modification non the casing for the cable, and now it works great.

I recommend everyone to check this if they have knowledge and instrument, and if possible at least repair bad soldering.

BooLE


I think you're completely wrong, if you check the orginal antenna plate and you will see it is linked together
check with your multimeter and you will get closed circuit on this 2 pads
even when you soldered off one on the circuit board

I don't know why this working better for you guys maybe cheep antenna

/Stefan

joe9002
Posts: 23
Joined: Tue Oct 30, 2012 8:19 am

Re: WiFi - hardware problem with antenna soldering

Postby joe9002 » Sun Nov 11, 2012 5:02 am

I had a short on one aerial and after my antenna mod from an old o2 router ive had no wifi problems so i agree with the first post , factory don't care + cheap rubbish = unhappy customers.

lukesan
Posts: 40
Joined: Fri Nov 09, 2012 5:24 am

Re: WiFi - hardware problem with antenna soldering

Postby lukesan » Sun Nov 11, 2012 11:12 am

Ok guys, let me first tell you that I have alot of HF experience.

You cannot measure an antenna with a multimeter, and certainly not its performance.
What for a multimeter is a shortcut is not for HF (wifi on 2.4GHz).

Now if you have an antenna of a old router you could use that.

Also you can create your own simple 1/4 wave antenna --> Frequency * wavelength = speed of light

frequency = (speed of light)/ (wavelength)

So for a 1/4 wave lenght antenna you need 2 pieces 0ft. 1 - 3/16inch or 0.030 M which means 2 pieces of 3cm will do. 1 connected to the 'ant' and 1 to the 'gnd'

I have yet to receive my MK808 so I haven't checked the antenna on the thing yet

devil66663
Posts: 32
Joined: Fri Oct 19, 2012 2:25 pm

Re: WiFi - hardware problem with antenna soldering

Postby devil66663 » Mon Nov 12, 2012 12:36 am

Hello

The Chinese burns the Isolation between live and shield!
Use half wave, it works better.
Solder 2 wire with 6,3cm on each ant Pad and you will see, it works

Regards
Bernhard

devil66663
Posts: 32
Joined: Fri Oct 19, 2012 2:25 pm

Re: WiFi - hardware problem with antenna soldering

Postby devil66663 » Mon Nov 12, 2012 1:59 am

lukesan wrote:Ok guys, let me first tell you that I have alot of HF experience.

You cannot measure an antenna with a multimeter, and certainly not its performance.
What for a multimeter is a shortcut is not for HF (wifi on 2.4GHz).

Now if you have an antenna of a old router you could use that.

Also you can create your own simple 1/4 wave antenna --> Frequency * wavelength = speed of light

frequency = (speed of light)/ (wavelength)

So for a 1/4 wave lenght antenna you need 2 pieces 0ft. 1 - 3/16inch or 0.030 M which means 2 pieces of 3cm will do. 1 connected to the 'ant' and 1 to the 'gnd'

I have yet to receive my MK808 so I haven't checked the antenna on the thing yet


Hello
Anyone can measure a short circuit.
The short circuit is directly connected to the antenna pads where the shield is soldered, burns through the insulation and producing a short circuit.

lukesan
Posts: 40
Joined: Fri Nov 09, 2012 5:24 am

Re: WiFi - hardware problem with antenna soldering

Postby lukesan » Mon Nov 12, 2012 3:46 am

devil66663 wrote:
Hello
Anyone can measure a short circuit.
The short circuit is directly connected to the antenna pads where the shield is soldered, burns through the insulation and producing a short circuit.



Well the antenna is short circuit for DC too so no matter if the coax is good or bad you will measure short circuit.


@Bernard.
Half wave. Then there must be something wrong with the rest because then the impedance will be extreemly high which results is only good for a balanced antenna.
Can you take a picture of your antenna structure?

devil66663
Posts: 32
Joined: Fri Oct 19, 2012 2:25 pm

Re: WiFi - hardware problem with antenna soldering

Postby devil66663 » Mon Nov 12, 2012 4:24 am

Hello

The Short circuit is directly on the Boardsite.
After i build my antenna it works perfect. (meanwhile 1week)
I used only a Monopoly-antenna.
If i had time i make a Picture.

Regards
Bernhard

lukesan
Posts: 40
Joined: Fri Nov 09, 2012 5:24 am

Re: WiFi - hardware problem with antenna soldering

Postby lukesan » Mon Nov 12, 2012 7:08 am

devil66663 wrote:Hello

The Short circuit is directly on the Boardsite.
After i build my antenna it works perfect. (meanwhile 1week)
I used only a Monopoly-antenna.
If i had time i make a Picture.

Regards
Bernhard



If it is the coax why don't you just replace the coax?

devil66663
Posts: 32
Joined: Fri Oct 19, 2012 2:25 pm

Re: WiFi - hardware problem with antenna soldering

Postby devil66663 » Tue Nov 13, 2012 1:32 am

Hello

I dont need this s.... filmantenna.
These coaxial cables are designed for crimping, no soldering.
You'd have to solder so short that you risk a cold solder joint.

Regards
Bernhard
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T68
Posts: 30
Joined: Thu Nov 08, 2012 7:21 am

Re: Sv: WiFi - hardware problem with antenna soldering

Postby T68 » Tue Nov 13, 2012 1:57 am

How do you open up the mk808 so you can access the internals?

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lukesan
Posts: 40
Joined: Fri Nov 09, 2012 5:24 am

Re: WiFi - hardware problem with antenna soldering

Postby lukesan » Tue Nov 13, 2012 5:30 am

Hi Bernard,
Lol at that photo. I think you are German so it looks like a 'Rasentrimmer' now :D

I have still to receive it... grrr takes a long time. The tools and proper coax I have at home so when I get it and wifi is bad I will try this first.

To be honest, these sticks are actually worthless things if you think of it. You have to attach a usb hub to it. They have no proper weight so they just hang there.
Also the lack of connections and connectors which do not have any mechanical strength because they are only soldered (lead free, yuk) will be in an issue over time.

scanja500
Posts: 5
Joined: Sun Oct 07, 2012 9:40 am

Re: AW: WiFi - hardware problem with antenna soldering

Postby scanja500 » Tue Nov 13, 2012 6:43 am

lukesan wrote: 'Rasentrimmer'


:lol::grin::mrgreen:


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lukesan
Posts: 40
Joined: Fri Nov 09, 2012 5:24 am

Re: WiFi - hardware problem with antenna soldering

Postby lukesan » Tue Nov 13, 2012 9:33 am

Sh*t it just arrived with a .... 1 Amp 5 Volt adapter. I guess this is not enough?

wings
Posts: 6
Joined: Tue Oct 30, 2012 3:03 pm

Re: WiFi - hardware problem with antenna soldering

Postby wings » Tue Nov 13, 2012 4:37 pm

1A seems good enough for web browsing or HD video reading.
had jumped previously on 2A adapter but didn't solve the antenna disfunction

lukesan
Posts: 40
Joined: Fri Nov 09, 2012 5:24 am

Re: WiFi - hardware problem with antenna soldering

Postby lukesan » Tue Nov 13, 2012 7:00 pm

Using another modified adapter which supplies 5V and which can deliver more than 2 Amp just to make sure.

First test : boots .... disconnect the device from the TV and as a true geek install Finless1.5a
Been testing this thing all night. I don't like the remote I bought with it. Getting cramps in my hands, sometimes types double characters and the mouse cursor is not what it shoud be.

Ok now wifi. Using a Linksys wrt54 which runs Tomato firmware and being B/G only ... I get 'good' 54Mbit/s and that seems like constant. The device is about 8 meter away from the AP.
Using the E4200 and N ... not working like it should dropped to 8Mbit/s while it was 58Mbit/s a couple of seconds before.
I suspect that there are series with bad coax or soldering, Ok wifi is not the best I have seen but I also have seen some tablets which suffer the same issue.

I have alot of interference on 2.4GHz which you cannot see on wifi analyzer since alot of them are not wifi signals. On the spectrum analyzer I sometimes see bursts which are strong. I suspect security cameras or some other stuff.
Why can't they make these things dualband so we can enjoy the quietness of the 5GHz band? More bandwidth and more space for everyone.

DonHutch
Posts: 1
Joined: Thu Nov 01, 2012 12:38 am

Re: WiFi - hardware problem with antenna soldering

Postby DonHutch » Wed Nov 14, 2012 6:52 pm

Well after reading and reading a lot of forums, about Wireless hardware mods, I'm in the mood of opening my MK808 and look for a bad soldering...

So far I've found is that the GND(Ground or Shield or outer layer of wire) and the ANT (Core layer of wire or Antenna) both are important depending on the board / chip , because in some cases 1 antenna is for data receipt and the other 1 for transmit, which can be the case of the MK808

So without unsoldering the coaxial from the board, i'll try to isolate the GND and ANT cables (probably gotta need to melt the extra welding) separate and then apply some cold silicon on the core layer, so I can get something like this:
Image

T68
Posts: 30
Joined: Thu Nov 08, 2012 7:21 am

Re: Sv: WiFi - hardware problem with antenna soldering

Postby T68 » Thu Nov 15, 2012 8:11 am

This might be a bit OT, but I recently opened up my netgear router since the plastic antenna broke off, just hanging on by the antenna cable.

Inside I found that there was no gnd or shield for the antenna. Just an antenna cable (not coax with shield) solded to the board. The cable then went out into the plastic antenna stick. The antenna itself is not attached with screw mount, only plastic attached to the plastic chassi of the router.

So apparently there are wifi antennas working without ground/shield.

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devil66663
Posts: 32
Joined: Fri Oct 19, 2012 2:25 pm

Re: WiFi - hardware problem with antenna soldering

Postby devil66663 » Thu Nov 15, 2012 11:44 am

lukesan wrote:Hi Bernard,
Lol at that photo. I think you are German so it looks like a 'Rasentrimmer' now :D

I have still to receive it... grrr takes a long time. The tools and proper coax I have at home so when I get it and wifi is bad I will try this first.

To be honest, these sticks are actually worthless things if you think of it. You have to attach a usb hub to it. They have no proper weight so they just hang there.
Also the lack of connections and connectors which do not have any mechanical strength because they are only soldered (lead free, yuk) will be in an issue over time.


Aber es Funktioniert ;)

Mfg
Bernhard


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