I'm gona hate this, but I think were on the wrong track. Sorry for the long post but...
The common types of pickup systems we have today are: magnetic, "Hall" effect, optical, and "ECKO". More or less In order of today's usage.
It seems our XS ignition system is a ECKO, "Eddy Current Killed Oscillator" system. The pickup uses two coils of wire wrapped around iron cores that has current flowing through them all the time. The sensor detects current disruption when a magnet passes near by. Pickup uses three wires, power, ground and signal.) Induction ignition, (TCI=Transistor Controlled Ignition) where the signal wire GN/W, relays a signal to a transistor ( SCR fast switching) when the pickup coils senses a current disruption. In this system the coil/s are also powdered at all times. The coil field collapses and fires the plug. So the magnet is not inducing a current in the pickup coil but instead, the TCI is watching the disruption of current it's providing to the pickup when the magnet passes. That also explains why the copper is around the magnet. The magnet's field is isolated from the rotors field and in this way provides a clean signal for disruption of current in the pickup as the magnet passes. ( I'd like to know the Ohms out the pickup on the orange/white and black/white wires.) And mention was made earlier about the coil/s to use. Induction ignition uses higher resistance coils compared to CDI systems that can use lower resistance coils. So we can't use low resistance type coil in an "induction" ignition (TCI) system unless it is specifically designed for that. The low resistance coil will flow more current thru the TCI. It will work for awhile, but eventually burn out the TCI module. I think the coil mentioned above, was in the 3 ohm range? Anyway, I think TJ used his XS pickup to fire Gonzo? If so, Gonzo is a TCI type and will work for someone just needing a TCI box and using their old pickup. ( Even if Gonzo works, if the old TCI pickup dies, soon it will be hell finding one of those. I'm very interested in the type pickup Gonzo uses, 250 Suzuki? I hope it's TCI and can be adapted to the XS.
The magnetic pickup, on the other hand, has to have a reluctor or vane to interupt it and make it work. That might be a trick to add. If your going to make a whole system, pickup and box, then you could put together a complete CDI system. CDI would work but it will be best to match the pickup and the CDI unit .
I'm looking into info on Gonzo's pickup to see if it's TCI. ( which should be the case since TJ got it to fire using his old pickup, or dragging a magnet across it.)
Oh, Man, The distance between the stock pickup coils will make a difference on where Gonzo thinks the advance should start and stop. Guess I have some more studying to do.
EDIT: Gonzo is a CDI unit. Figures.