Thanks StayyerAU. V good point !
Reg Sniff ( TDI SL US guru) says the TDI SL will run a DD and I have an old 350 DD Pro Coiltek and after reading your post I double checked the field on that coil on the SL & it detects on both sides of the centre line with the centreline more sensitive so I guess it is working as a proper DD.
Yeah not too many small DDs out there. There used to be smaller ones available, especially in USA. I am looking for something that ideally has a smaller effective footprint than my 8x6 Sadie ie <7" round.
If I cant find a v small DD I might have to go a Minelab 10 x 5 DD or that 8 DD Detech in your post.
If anyone has either of those second hand I would be interested.