The answer isn't always in the subject or in the first few posts. I too was looking for how to tell the difference a little while back and searched and ran across the thread in the link below. I used the same search criteria you did.

http://www.scrapmetalforum.com/showt...light=ballasts
Towards the bottom it has BRASSCATCHER saying "They should as long as they say non-pcb somewhere on them." This leads me to believe that the ones with PCB's in them dont have this marking. Now I dont take it as a hard and fast rule because there could be one without PCB's that doesn't have this marking but its a place to start.

Lots of time you will find a post that someone says "Hey I found some ballasts and got rich off them" Then further down someone else will say something like they found some that were just like those and you could tell they were the good kind because of X. Think of your search as bringing up every post that contains what you are looking for but the more you look through it the more you will find.



As another example I was looking to buy a scale to weigh my e-scrap. So I searched scales and passed up all the people talking about the scales at the yard that seemed to be off (but earmarked to pay attention when I go to the yard), passed up the posts with people talking about the scrap scales that they picked up, and eventually settled on two or three good posts about different kinds of scales and who is using what scale. Now I have in my mind the scale i want to buy but I had to dig for it.