Mini-PCI wireless antenna placement in T23- huge signal gain

[skydreamer]

Having read many suggestions on the WiFi antenna placement inside the T23 including the very detailed Raymond's link below:

http://www.rkawakami.net/ibm_t2x/t23_wireless/

I went on experimenting and made a very interesting discovery.
I have got an Atheron 5212 based card with two antennas, one went under the keyboard bezel and the other one next to the CPU heatsink but the performance was mediocre compared to an external PCMCIA card. I was testing the signal strength with the top cover and the keyboard off and the aerials (little PCB's) sticking out but the signal gain was only around 5dB (67dB) when compared to the fully closed laptop (signal at around 72 dB).
Then I tried something counter intuitive that brought the signal strenght to unbelievable 60dB (while noise stays at 92dB)- screwed the left antenna onto the CPU heatsink so that it is now sticking into the PCMCIA compartment. I had to put a washer under the screw fixing the heatsink to the MB to lift the antenna up away from the sliding path of the top PCMCIA slot. The screw is located on the Raymond's link above on the last photograph touching the bottom edge. And yes, it actually makes electrical contact too, there is a hole in the antenna's PCB perfectly fitting the screw with conductive material around.
The signal quality gain from the left (heatsink fixed) antenna is now such that it makes no difference if the right antenna is plugged in.
I will try to experiment with the right antenna placement, perhaps will be twice lucky?

As to why the performance is so much better I have no clear explanation. The longer the aerial the better the signal as long as it is at the transmitting wave length or multiples of it (fractions also do 1/2 or 1/4, at a signal loss). Since it is not practical to have a 6cm (5Ghz) or 12.5 cm(2.4 GHz) antenna inside- maybe the CPU heatsink is the perfect fit?

[RealBlackStuff]

That sounds almost too good to be true!
Any chance of taking a photo and publish a link to it here?

[RealBlackStuff]

Hey skydreamer, any follow-up on your post?
I have a self-made wireless T23, which could perhaps benefit from your 'accidental' knowledge.