The WLD will go to 2 MHz in constant current mode and will have a depth of modulation of 100% at 1 MHz or more. It starts to roll off once one gets past 1.8 MHz, it drops 5-10% at 2 MHz and holds there well with a 2 MHz square wave. It will perform slightly better with a sine wave. But 10 MHz will roll off significantly and probably will not be usable. The output signal rolls off to zero at about 6 to 7 MHz; depending on the amount of current needed, it might work up to this range.