The brains behind the system is the PA3 or SPA4 controller from Spectrotek Systems. It is developed by a devoted engineer and HAM radio enthusiast, Ralph Hartwell, and sold at a very favorable price. It is made to replicate Rife’s original setup as much as possible.
Assembled system
Here are pictures of my system. It is based on the SPA4 controller (although I recommend the PA3). It has been assembled in an enclosure designed for a power amplifier. My rig is not the prettiest in the class - but it works.
The PA3/SPA4 needs a large heat sink assembly to cool the main mosfet (a component that gets hot when you run your tube). I put the heat sink assembly on the outside of the casing, which works well and there is plenty of fresh air. And house dust… ahem :-) I put as many components as I could inside the casing.The 19volt output is handy to power the frequency generator and fans.
The SPA4 can have several switches controlling the operation, I ended up removing all of them. If no switches are connected, the SPA4 defaults to the most idiot-proof operating mode. No further comment :)
The SPA4 controller casing on top, power supply beneath. The system is set for 75 volts, the tube is not lit (no current flowing and no duty cycle).
This is the inside of the casing. I opted to have the main STW mosfet heat sink assembly on the outside of the enclosure, as seen in a previous photo. (Note that this is the previous version of the board. The last version from Ralph has more noise filters installed and is slightly bigger.)
This is the plasma tube mounted in a shelf from IKEA, with plastic wrap for protection. Not the most elegant solution, but it works. The plastic wrap keep nosy cat and clumsy hands from touching the high voltage equipment.
The tube lights up beautifully, even at low voltage. If you are sensitive, you can sometimes feel it in your body, even with your eyes closed and blindfolded.