Does anyone know what the voltage signal to the leading ignitor must be before the coil will successfully fire?

I'm trying to use the second gen coil on my first gen. I don't believe my pickup sends adequete voltage to fire the ignitor, which results in no spark. So what can I use to boost the signal?

 

The voltage signal received from the ECU is a 5V logic signal. The signal will go positive (close to 5V), and will then transition back to ground. The ignitor fires on the ground transition. In a second gen, the pickups supply AC signals that are interpreted by the ECU along with RPM and other conditions to determine when the logic signal fires the coil. Hope this helps.

Irv, Keith's dad

PS The ignitor case must be grounded for it to work.