Just My Opinion:
Any coins refered to are Aussie coins.
To cut a long story short, this is what you should do to get the best chance of finding gold with the Infinium.
!!!! DIG ALL SIGNALS !!!!!
If you must pick and choose then dig all signals that are hi/lo at zero disc and are hi/lo at a reduced signal level in rev disc. or that fade out completely.
Gold can be either hi/lo or lo/hi. (Large nuggs are likely to be lo/hi at zero disc.) All hi purity gold will be hi/lo in rev disc)
Dig all signals that are lo/hi at zero disc that change to hi/lo in rev disc.
Don't walk away from any signal that is hi/lo in rev disc at any sort of reduced signal level no matter how slight the reduction.
To find silver. (.925 or better)
Dig all lo/hi tones . Silver alloyed with other metal can be hi/lo
Most aluminium cans are also lo/hi at zero disc and rev disc. as are iron tent pegs, coat hangers, clean nails and larger nuts and bolts.
Bits of sparkler wire and other soft iron items give a LO/Hi tone in both modes and are of almost equal strength signals. One and two dollar coins give a warbled HI/LO LO/HI in normal and change to HI /LO at a disc setting of approx 3 or 4. Of all Aussie coins the one and two dollars detect at lesser depths at zero disc than our other coins due to the poor conductivity of the metal. i donot recomend trying to ID targets other than gold from iron.
I have found as a rough guide, that any strong HI/LO signal in normal mode that all but disappears in Rev disc at the beach is very often a steel screw cap. A strong signal from gold or silver will not disappear in rev disc but it will reduce somewhat.
So from this maybe you can see why I say Dig All Signals.
The discrimination on the Infinium is not ment to be a wide range discriminator, it is designed to separate gold from iron in gold field conditions. If you must use the discrimination to try and identify other targets like coins and various items of jewellery then you must experiment with a wide range of coins and other targets to get an idea of how the Infinium responds to different items at different settings of the discrimination dial.
This is how my Infinium (2004 Model)responds to small gold in air test.
Later models seem to be not as sensitive as reported by other operators.
Vol control set 1/3 up from minimum so that max was not too loud.
Threshold at 4.
Headphones used: Standard Garrett HPs supplied with the Infinium.
Sound level meter weighted for flat frequency response between 100hz to 10,000hz.
1/4 inch from HP speaker element.
Nugget= 4.7gm solid.....80db (max voume) at 8cm.
60db (75%) at 17cm.
54db (65%) at 22cm.
0.55gm solid................62db (77.5%) 3cm.
54db (67.55%) 8cm.
0.14gm solid flatish.......58db (72.5%) 3cm.
53db (66.25%) 4cm.
below 50 db............ 6cm.
Using the db meter eliminated any errors due to hearing loss.
I will see what running the HP vol at max does and also setting the threshold high.
I will try a set of more sensitive HPs later and see if there is a noticable difference.
The following shows the infiniums response with 3 different sets of headphones with differing sensitivities\ and impeadance. detector threshold at 6 and disc at zero.
1 Standard garret land HPs supplied with the Infinium
2 Garrett Clear Sound
3 Scaler - 30B
STD:
4.7 gm nugget....... 96db max at 9cm.....86db at 15cm.....23cm detection limit (nil signal)
0.55gm nugget.......90db at 6cm......80db at 10cm......15cm detection limit.
0.14gm nugget.......80db at 4cm......76db at 6cm........7cm detection limit
Clear sound:
4.7gm nugget.......84db max at 10cm.......80db at 12cm......23cm detection limit
0.55gm nugget.....80db at 4cm.......70db at 10cm.......15cm detection limit
0.14gm nugget.....70db at 4cm 7cm detection limit
Scala 30B:
4.7gm nugget......102db max at ......10cm.......90db at .....14cm.......23cm detection limit
0.55gm nugget.....92db max at 4cm 82db at 6cm....... 15cm detection limit
0.14gm nugget.. 80db max at .....4cm.......74db at ......6cm..........7cm detection limit.
So from this it can be seen that for each particular nugget the maximum detection limit remained the same irrespective of the HPs that were used. which of course is correct because after a particular distance no detection signal will be produced because there is nothing to amplify.
if you notice an increase in detection depth when you use a more sensitive set of headphones it is due to a certain degree of hearing loss of the operator being compensated for when the more sensitive HPs bring any remaining or existing signal up to a level that overcomes the hearing loss, not because the Infinium is detecting any deeper.
Of course if you use a set of high power HPs that require a high voltage input signal above what the infinium is capable of, then you won't hear anything at all.
Last edited by Adrian SS on Thu Sep 08, 2011 7:07 pm, edited 2 times in total.
