Up for 'buy it now' are these Made In USA 3/8" very handy Female Weld On Cable End Repair Links for Popular Slotted End Style Cables.  This is for cable size 3/8" and is the Female Cable End Only. 

If you've twisted off the end that secures the bit to the cable or you wish to change to the slotted end style cable, I have weld-on female ends in stock for your 3/8" cable. These are very easy to install as long as you have a mig or oxygen/acetylene welder. They are an inexpensive quick permanent fix and saves you the cost of a new cable.

The slotted cable end is used on General, Cobra, Speedway, Brasscraft and Harbor Freight's Hydrostar and many other Chinese made drain cleaners.

Just slip it over the broken end of your cable and weld it on and you're good to go.