Well might have sorted it out.
Reduced the size of the fuse before the BR, still same problem.
Decided to get serious and put the old tong tester directly after the main fuse, before the MOV and line filter.
Set it up to 'peak' and checked the amps.
Couldn't get the peak amp draw above 2.1 no matter what I tried.
Still blowing the main fuse every other time.
Had me screwed, by this time I have gone through 8 or so 4 amp fuses.
Then I thought about it, bought these fuses as part of a large assortment off the net.
Changed to a 3 amp Bussman fuse, so far not blowing.
Cheap fuses might be OK on the secondary side of the transformer but definately not recommended on the line side.
If I have got this wrong I will post accordingly, but in the meantime if any of you got the cheap fuses on offer a whiles back, you might want to think twice about using them on 240V!
