latest detectors not picking up gold

I have found some nice pieces although small gold that the detectors haven't..
This is 6" gravel over metre or so of clay in crab hole country and snake bush tree arears in the Pilbara.

Pieces found go as high as 1.5 grams and there are quiet a few small ones that should have been nailed but to no avail..

Has anyone had any luck on these Pindan soils and would switching the machine into normal and using a DD coil or anti interference coil help..Interesting..

yep back in town again --something else has come adrift on the machine...always something new to deal with..i'm patient.

regards
oneday

G'day Ray,
I spent a some time out at mt regal after everyone had well and truly gone and worked around that snake tree crab hole country using a 4500 in enhance and a 5000 fora few days also.
At the time I liked the 5000 but I now realise I didn't. Have it set up correctly.
I can tell you I found small stuff everyday and got a couple of bigger bits in that crab hole ground, I wish I knew what I know now as I'm sure the 5000 would have done well with the correct settings .......I still miss the pilbara
Regards snapper