Nice work Jet.

Check out my post about alternate tuning sg theres a diagram there as to how I set up the scr. Mine is the same as Ricks except the scr is in the positive leg. My understanding of the scr is that it is like a diode, but it has a gate function.

Here is a excerpt from Wikipedia.

" When the gate to cathode voltage exceeds a certain threshold, the device turns "on" and conducts current. The device will remain in the "on" state even after gate current is removed so long as current through the device remains above the holding current. Once current falls below the holding current for an appropriate period of time, the device will switch off."

I have been using a resistor in line with the diode that triggers the gate. I could be wrong but I think the voltage that builds up in the cap has to be strong enough to (a) be above the voltage of the cathode and (b) be high enough to overcome the resistance and diode to trigger the conduction.

Some one can set me straight if it isnt what is happening. Id be interested to see if there is much difference in having the scr in the positive leg or negative leg of the charging circuit.