Setting txpower above the power of your card

[Scott Stapleton]

Hi,

After setting hostap up, I noticed the default txpower from my card was
4dbm ( 2.5mW ). I procedded to set my card to 20dbm ( 100mW ), as this
is what it outputs ( WL200 ). I noticed the NS graph on my lappy shoot
up, as expected.

I then thought I'd try setting it to 150mW to see what happened. I never
expected it to increase, but it did somewhat. I then proceded to try
30mW, then 100mW again. The signal did not increase this time after I
changed from 30mW to 100mW.

Is it possible to overpower these cards? I have not used the card a lot
since, but it still seems to be working. I only left it at the 150mW for
30 sec's max. 

Is it possible I have damaged the card.

A friend did a similar thing previously and left the power set higher
for a much longer period ( days even ). His card is a Dlink running
HostAP and the box now dies and a reset is needed to get it working
again.

Whats the chance of damage and if it is possible, why is it allowed,
either by the card or driver?

Regards,
Scott