Simple and Working Wifi Antenna Quad Mod

[Dero]

Hi, I was looking at the mods some of you guys did and "invented" my own mod, base on a a round quad-antenna.

AFAIK, the shape of a quad antenna is not really important, only the TOTAL length of the cable has to be equal to the wavelength times the copper shortening factor (0.975), hence roughly 12 cm.

What I did:
- completely removed both built-in antennas
- clipped off the two antenna pins (the one close to the USB port), MK808 v1 doesn't have pins
- soldered a 12 cm piece of copper wire with one end to GND pad and the other end to ANT pad, the ones close to the USB port (take care that you don't kill one of the pads)
- drilled a small hole into the case
- bent the wire like an ear

Works very well! 100MBit download from internet improved from 16 s to 4 s, i.e. from 6 MBit to 24 MBit.

Be aware that the antenna is directional. In theory, that's the optimal positioning:
- let's assume the MK808 stick is a head, where the OTG port is the nose, the HDMI port is the throat, and USB+power is the scalp
- then the antenna is the right ear
- assume you have a wifi router with a normal rod antenna
- the rod-axis and the stick-head-axis must be parallel, i.e. if rod is standing upright, stick must stand upright (to have the same polarization)
- the nose of the stick-head must point into the direction of the rod, i.e. the quad-antenna is facing planar to the rod

I tried also to extend the antenna to a biquad by soldering another copper wire to the other GND/ANT pads (close to OTG port), but somewhy the signal dropped badly and I removed it again...

dero

BTW. I have another stick, where I killed both ANT pads while trying to solder and I can't get any wifi anymore. However, I could get an Edimax ew-7811un to work. But, I would love to fix the antenna pads. Does anymore know a bit about the circuit wiring of the MK808, i.e. where could I attach the antenna to?

WP_20121220_001.jpg

[itsme]

This works.

Plus extra kudos for the Picasso face/head/antenna description, really into surrealism there!

[Dero]

Thanks!

BTW, I get even better reception if I squeeze the antenna to look more like an elliptical folded dipole than a circle-quad, i.e. push the outer side of the ear to the head until roughly 1 cm is left.

Code: Select all

 ____________________
/                    \
\_________  _________/
          | |
        GND ANT


^single core wire with roughly 12 cm (one wavelength 12.4 cm multiplied by copper velocity factor of 0.97) soldered between GND and ANT and bent to a folded dipole.

I also experimented with a reflector: put a metal plate 14 mm behind then antenna. A bit of gain, but not worth the PITA to glue it to the right position...

Dero

[firefly1010]

Works like a charm
I can even see my neighbours Wi-Fi, which is in a house 20M away
Here is how mine looks.

[Dero]

Good work!

Your antenna looks very "lathy". I got even better result "pushing" it down to look more "fatty" (folded dipole).

dero