It's a Faraday Shield he has done and just basic physics blocking the signals.
Only thing is it will also probably interfere with any headphones and WM08 so would need hard wired headphones to the...
on an american site I belong to someone who had a serious EMI problem on the beach came up with the novel idea of covering the control with kitchen foil. It worked!
another contributor said:
"I...
this was answered on 'Detectorprospector' some time ago
so it's easier to just use the reply from there:
Park 1: General / Coins
Park 1 is optimised for modern coins and larger jewellery with a...