In this paper, we look at the existence of ðv v; KÞ pairwise balanced designs (PBDs) for a few sets K of prime powers ! 8 and also for a number of subsets K of f5; 6; 7; 8; 9g, which contain f5g. For K ¼ f5; 7g; f5; 8g; f5; 7; 9g, we reduce the largest v v for which a ðv v; KÞ-PBD is unknown to 639, 812, and 179, respectively. When K is Q !8 , the set of all prime powers ! 8, we find several new designs for 1,180 v v 1,270, and reduce the largest unsolved case to 1,802. For K ¼ Q 0;1;5ð8Þ , the set of prime powers ! 8 and 0; 1, or 5 (mod 8) we reduce the largest unknown case from 8,108 to 2,612. We also obtain slight improvements when K is one of f8; 9g or Q 0;1ð8Þ , the set of prime powers 0 or 1 (mod 8).