Wait, I finally figured out where I was having problems. I was thinking impedance which is a result of an AC current flowing through the capacitor. Not really flowing through since the alternate voltage will suck the power off the cap as the wave form varies. The diode doesn't really isolate the cap, it changes the RF into pulsed DC and there is no bottom side of the wave form to affect the cap. This means that the cap will charge up to peak voltage in a few cycles and essentially stay there.
None of the sites clarifies this simple little item. I even looked at a bunch of power supply calculation examples trying to understand why the impedance of the capacitor wasn't a factor other than filtering the pulse by discharging along the current path. My kind of thinking (related to AC impedance) comes from calculating the proper capacitor value to control a ceiling fan since a resistor would have to be too large and a triac introduces way to much noise into the motor assembly (causing a buzz).
I was right about the diode forward voltage drop though