Right Phil, that's the question.

Imagine how much you'd trust that coil with the occasional puny little spark it made if you didn't already know it was a good part.

Ignition Amplifier or Power Stage

The photo I included is the ignition amplifier with the cover removed. It is a good one. Working one. I still have not run into a defective one in all these years and all these cars. Yet we replace them all the time on this forum, don't we?

You've got a better picture in the Bosch Handbook you told me you bought -- on page 116 in the Battery Ignition chapter. The text explains all the functions this "simple little solid state relay" performs, such as feedback dwell (charging current/time) and protection against leaving the key switch on. It has some brains:



Manually Testing Coil

The best way, in my opinion, to get the same spark you'd get from the coil in a running car, is to use the power stage to charge and discharge the coil:



If you really want to become the breaker points with a clip lead to ground the negative terminal of the coil, add a condenser. This will squelch the spark at the primary break which tends to dissipate all the magnetic collapse energy meant for the secondary. Then it will spark every time, and with enough voltage to jump the 3/4" gap proving it.









--
Art Benstein near Baltimore

Good research: Charles F. Kettering Dayton Engineering Laboratories (DELCO)