I clipped this from the newspaper a few years ago. It doesn't include ketchup, but there's no reason it couldn't be added. I haven't made it yet, but I'd probably add a little brown sugar as well as some ketchup or BBQ sauce. Adaptation is what cooking's about, don't you think?

1 tsp. vegetable oil
3 reduced-fat beef franks
1 (28-oz) can baked beans seasoned with onions, bacon, and brown sugar
2 (14.5-oz) cans vegetable or fat-free chicken broth
1/2 tsp. chili powder
1 tsp. spicy brown mustard
1/2 lg. green bell pepper (3/4c. chopped), optional

Heat oil on medium heat in a 4.5-quart Dutch oven or soup pot. Cut franks into 1/4" slices; add to pot. Cook until franks start to brown.
Add baked beans, broth, chili powder and mustard. Stir well. Raise heat to high and bring to a boil. Reduce heat to medium to maintain a moderate boil. Seed and coarsely chop green pepper; set aside. Let soup boil for about 10 minutes to blend flavors, adding green pepper for last 5 minutes of cooking. Serve at once.
(If kids will be served the soup, you might want to omit the green peppers. They often don't like them. Or ladle out theirs and then add the peppers to the rest of the pot.)