More than enough to get one into trouble with the FCC, I'm sure. The design allows you to set the carrier level and the modulation level independently from almost zero, to the stated specification, with no change in fidelity or circuit components. Yes, you can run 0.5 watt carrier, and modulate it to a 2 watt peak if you like. More comments, some repetitious, are at the end of the page. The circuitry described herein uses deadly voltages and dangerous power levels.
Tubes can become very hot and cause serious burns if touched.
Always use caution when building or working on high voltage equipment. God is only a prayer away, and a couple hundred volts is all it takes to meet Him. This design is proven by experiment. The modulator avoids the use of a modulation transformer and employs pass-tube technique to regulate its output. Audio voltages applied to the modulator's input are amplified along with any error voltages and supplied to the modulator's output.