Diagnose Coil

[30ccpickup]

http://modelabasics.com/pics/38sparc.mp4

I am fairly new to this side of the site and am a self taught Model A guy. In my research for my 38, I see many questions on how to check a coil. (Envious of the Herbrand 660). For the Model A, I use a homemade device that connects between the distributor and coil. It checks the color of the spark. Blue good orange bad. I made a similar device for the 38 that connects between the distributor and spark plug to find my miss.

Now comes my lack of knowledge.
Let's say someone has the problem of, "runs bad and/or no start, once warm". If they connect my device and drive around for a while to warm up the coil, then check the color of the spark, would that diagnose the coil?.. or would the condenser still be in play… or would you have to have either the coil or the condenser known as good to diagnose the other?

 

[30ccpickup]

http://modelabasics.com/pics/38sparc.mp4

 

[ndnchf]

I'm no expert, but I do have a Herbrand tester and have checked good and bad coils and condensers with it. Since the condenser is balanced with the coil (in a perfect world), either one failing would show a weak spark. Fortunately, its pretty easy to swap a condenser to see which is the culprit.