Jens,
The power output is determined by the input voltage and the drive setting. Are you using batteries? If there is a sag in the voltage when your radio goes into transmit, the output power will go down. Although you can crank up the input voltage upto 12V it's not recommended as the heatsink on the radio can get quite hot given that the 5V linear regulator has to drop the input voltage.
?
Can you please confirm if you've set the drive to 100??
?
73,
Ragav
