The brakes are setup all WRONG.
first up, pads need to sit closer to the rim.
second, the yoke shouldn't be that high. The straddle cable should be just slightly above the crown and bridge eyelets
third, if the pads are original, and have never been replaced, they're probably rock solid from drying out and need to be replaced.
reference:
Okay:
1. maybe I moved the pads around to a less than ideal position, but the bike braked badly when I first started riding it.
2. the cable that has the little 'tabs' on it that pull the calipers up is a
certain length . If I lower the yoke, the brake pads will rest even farther away from the rim... how can this help?
3. I said in the OP that I had replaced the pads twice in a last couple years.