Hi,

I have found that we can use in shell "wl" command to see current TX Power and we can adjust TX Power with this command. I don't know what max values we can set TX Power in WRT54?

root@SP2ONG-home:~# wl txpwr
pwr in mw 76
pwr in mw after override adj 76
79
root@SP2ONG-home:~# wl txpwr 100
root@SP2ONG-home:~# wl txpwr
pwr in mw 80
pwr in mw after override adj 80
100

root@SP2ONG-home:~# wl txpwr 255
root@SP2ONG-home:~# wl txpwr
pwr in mw 96
pwr in mw after override adj 96
251

In help of "wl" command with txpwr :

txpwr   Set tx power in milliwatts.  Range [1, 84]. (<-- ????? I have try use 255)   

txpwr1  Set tx power in in various units. Choose one of (default: dbm): 
        -d dbm units
        -q quarter dbm units
        -m milliwatt units
Can be combined with:
        -o turn on override to disable regulatory and other limitations
Use wl txpwr -1 to restore defaults

You can see table with max TX Power on www page: http://db0fhn-i.ampr.org/wrt54gs/

You better be careful or else you can burn out the transmitter. Best put a heat sink on those sensitive TX components too.