but i thought a cock split for the mutation could only produce female opalines. Soes it make a difference that the hen is opaline too?
yes it does....
opaline is carried on the X chromosome = sex linked.
male budgies are X/X
female are X/Y
so if you have a male that is opaline he gives all his chicks an X chromosome with the opaline gene = Xopl.
If the hen is not opaline she will give half her chicks an X chromosome without the opaline gene (X) so those chicks will be X/Xopl = split opaline cocks. the other half of her chicks will get a Y chromosome from her so they will be Xopl/Y = opaline hens.
if the male is split opaline he gives half his chicks the opaline gene so you get half the hens opaline.
if the hen is an opaline though, she is Xopl/Y and when bred with a split opaline male X/Xopl (like yours) you get these possibilities:
Tonic is correct. A male split for opaline can only produce normal hens, opaline hens, normal cocks, and normal split opaline cocks. However because this cock was paired to an opaline, she passes one opaline gene to all her sons. This means when she is paired with the cock they can now produce normal hens, opaline hens, normal split opaline cocks, and opaline cocks.