Hi Tom!
No egg that I can see on your face.
Sounds like you're now beginning to understand how that 1:1 transformer really works.
Although your test components might be damaged goods at this point....
Your receiving cap should really be rated at a bare minimum of 400v though. 100v peak tolerance, I'll almost guarantee you, is letting some of that EMF blast through the innards of that capacitor.
Here's the big advantage in using this system for boosting voltage. You can vary the output voltage ANYWHERE inside the maximum EMF voltage that you can collect on the capacitor. If you want 120v pulses, just discharge the cap at the 120v point. Controlling that discharge with a transistor will let you do a limited discharge, say, only down to 100v, then stop the output pulse. This lets you rock the cap voltage back up to 120v and then dump another pulse. This is how you power a 120v load efficiently (heating element?). It's only a little different than using fixed voltage AC. The cool part is that in a real pinch you can build a purely mechanical system to do this so you could run HV loads from a low voltage battery bank. So many permutations available that it can be a universal fix-all for load control.
For example, Put a 25% duty commutator on your motor shaft. Wire the commutator between your power source ground and the negative lead of the transformer primary. Hook the motor terminals between battery positive and the transformer positive. Then give it a spin to get it going. You might want some flywheel mass on the motor shaft. Now you have a mechanical transformer driver with no solid-state parts. But, you WILL have a small light-show on the pulse-commutator.
Anyway, I'm rambling again....
Your component problem (my take on it anyway):
If you're peaking out at 65v or so, you should do a DC charge test with 120v DC to see if the cap is now leaking current above the 65v threshold. I'd be suprised if it isn't.
I've ruined several LARGE low voltage caps with direct emf collection. Now I put a bunch of 600v caps across the primary emf reception point, ALWAYS. Then run wires from that small bank, down to the larger caps.
Even though you're only putting 5v DC pulses into the primary, the emf voltage is always WAY above that. Basically, the emf voltage is a function of the field-collapse speed as it falls back into the core (almost the speed of light). That's why the rectifier bridge needs to be a 1kv tolerance and the caps should be at least 400v tolerance.
Once you have the high voltage components in place, all you need to do is adjust the pulse-width and frequency for max transformer transfer efficiency.
When transmitting the power down a long wire, let the receiving caps develop maximum voltage. Then pulse THOSE HV caps through a bucking inductor(see the DC-DC tutorial page), down into your low voltage bank. I'm piecing together a comprehensive block circuit diagram that will be in the diary section shortly. Not much time to play lately because they've been keeping me for O.T. at work the last few weeks.
I'm going to now suggest that you spend a couple of dollars and order one particular book. Barnes and Noble usually have one on the shelf.
"The Inventions, Researches and Writings of Nikola Tesla", ISBN #1-56619-812-7
Start reading at the bottom of page 202, "Now compare this phenomenon which you have just witnessed....."
This is where he is describing some of the first observed differences between his high frequency AC systems, and his systems that operate by "adjusting the discharge circuit so that there are NO OSCILLATIONS set up in it..."
Here's where he is beginning to demonstrate how pulsed DC systems prove much more practical and useful in many ways than his older AC designs.
These are the "uni-directional pulse" systems that Peter Lindemann describes in his books and videos.
In a nutshell, with this 1:1 tranformer thingy you're only touching the very tip of the iceburg. It only gets more interesting the deeper you dig!