It's hard to tell from the picture but it sounds like blossom end rot. You should check the FAQ over on the tomato forum and/or re-post this over there. That forum is much more active.

Rodney

Here is a link that might be useful: Growing Tomatoes Forum

thank you. Here is a pic of the black spot. The pic above is one that was healthy and ripe!

Wow - your 1st shot of the cherokee purple is beautiful!

Pathydroman:

How is the yield? I grew Cherokee Purple twice. I found it
to be the best tasting tomato I ever grew but the worst for yield. Wimpy growing vines and not much fruit. If my garden was bigger, I would grow it again just for the flavor .

Well so far so good. I have four plants and they are producing well for me. The first week of ripe ones I got a little over a pound from three of them. Here is a pic of Two that I harvested, the other one got sliced before I remembered. They are very dense and very juicy. Ill post another pic of one sliced open. Right now I have 3 more ready to pick and about 50 in total still left in all different sizes. So I am very pleased right now with harvest numbers.

Thank you Shane11