Halos my thought on them , all metals will erode except 24 kt gold some faster some slower they will all form a halo over time if the soil receives moister once a halo forms it dose not get bigger and bigger it actually get smaller over time as the metal erodes away . Rain after rain the fringes of the halo get wash down never letting it build . Let's look at a halo say iron it forms ferrous oxidized that is not metal it can't conduct electricity you don't detect anything more once you get the iron out . In fact these ferrous oxidized grains are not even connected in the soil there separate from one another like a gold chain . So how can it generate a signal though tiny grains of ferrous oxidized I look at it this way the ferrous oxidized is making it hard to hear the pure iron signal lol . Now as to the halo making the target seem louder and hit harder I am going to say no .
24 kt Joe digs a 12 inch dime tells his friends he only got it because of the halo , well I will say he had everything working for him perfect conditions and that's how I see it .
Now as to the ? I think I answered it .
Also trying to correlate ground balance numbers changing with different soils.
These will only change with different levels of mineralization OR you have tons of bottle caps nails or just plain thrash the #s will go down I often think the #s go down because it's to much for the machine to handle so as the ground becomes more cluttered with targets it wants to eliminate the deeper targets and try and id the mid range and shallower targets by reducing sensitivity . sube