If the Hebrews had no J than explain this?

The original pronunciation of YHWH was probably YaHWeH. This seems to be the case by examining Jewish names. Many names contain part of the divine name, i.e. yah, and by examing the vowels that they used to construct their names with the divine abbreviation attached, we can get a feel for how YWHW was originally pronounced. We conclude from the examining names such as Joshua, Jehoshaphat, Elijah, and even the word hallelujah (hallel=praise; yah=Yahweh), that YH was pronounced as yah. We also have evidence that Yahweh is probably the correct pronunciation from examining the Greek’s tranliteration of the divine name as iaoue or iabe.