John's right. I use Dayton interconnects from Parts Express, and am very pleased with them. You mention a 15 ft. cable. If a 12 ft. cable will do, I think this would do the job just fine.

http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=18676714&St=7978&St2=89256733&St3=72761411&DS_ID=3&Product_ID=117461&DID=7

Jack

"People generally quarrel because they cannot argue." - G. K. Chesterton