Rodney

I have not examined any real late design receivers but; in the past, what limits the voltage is the breakdown voltage of the capacitors. To keep them physically small, the breakdown voltage is very low, often just 6 to 10 volts. Also, the internal voltage regulator in the reciever (most have the rf stage running at about 3 volts) will get excessivly hot at the higher voltages and this can lead to early failures.