Well 90% is close enough to 100%. And used on Victorian goldfields.
So here are my main points on each of them after using all the Vlf's you've mentioned on both hot and dead quiet ground in Victoria. Although you've excluded the best one, I'll mention it anyway.
Gold Bug 11:
3 coil choice of 10x5, 6x4 and 14", all elliptical.
The very high frequency of 70khz alone makes it very shallow searching, unless a larger deeper piece on quiet ground sends it off.
They are beautiful to work over dead quiet ground and on both reef mullock and mullock heaps in general, and scream on tiny pieces of gold.
They are 5/8ths useless on hot ground. See below in the bracketed paragraphs.
Fisher F75ltd:
Around 13khz. Good coil choice.
Much better than I thought they'd be. Really nice to use on dead quiet ground.
Cannot handle hot ground, it upsets them to no end, but due to the lower frequency compared to the higher frequency units they do a bit better at it.
They run a touch better with a big drop in gain. I use that American term for sensitivity simply because you won't Gain much at all dropping the sensitivity so low to be able to run on hot ground. A ridiculously high gain was placed in them.
So overpriced at $1600 It's a mockery though.
See below bracketed paragraphs.
Whites GMT:
50khz, good coil choice for them. Again, great to use on dead quiet ground. Hot ground upsets them.
See below bracketed paragraphs.
Garrett AT Gold:
So much could have been done with this unit, but they just went backwards again. This is not 1985.
See below bracketed paragraphs.
Infinium:
Shocking coil choice, along with shockingly bad coils.
The most badly designed detector made to date, and to think it's still in production, is to me anyway, quite unbelievable.
You must remember, that while it began and still is being marketed as an all rounder with a dive depth of a couple of hundred feet and a new beaut reverse discrimination, they were also marketed here as a full on Gold Detecting unit that could handle hot ground, getting 2 to 3 times the depth of a 'typical Vlf'.
Truth is they weren't as deep as a Minelab gold Vlf run with a big coil in the correct frequency over hot ground, or as sensitive.
*(Welcome to the bracketed area.
This is a place where we can secretly chat about why Whites, Garrett, Tesoro and Fisher haven't bothered to produce a usable gold detector over hot ground. And not just here in Australia either, plenty of bad little patches of hot ground on the goldfields in the States as well.
The engineers that design these detectors are dinosaurs of the industry. Not only can't they come up with step forward in regards to improvement of the units, they can't even keep up with the times.
They are still producing 1980's models of detectors, as that is where they are still stuck in regards to R and D.
Even when designing digital units, they use the same 1980's outlook on Ground Balance, the all important Threshold, and Tone.
They only thing they seem to place any futuristic importance on is a ridiculously silly Boost of Sensitivity.
There are reasons why the AT gold, GMT, Gold Bug's and F75's cannot handle hotter ground. They are designed with really bad Ground Balance and correlation between Balance and Threshold.
There is no way you can work, tweak, operate correctly, tune or whatever words you'd like to use, to get these units to be able to detect deep over hot ground to detect gold.
Why?
Because the designers cannot even match the Ground Balance to Threshold correlation of a Minelab 15000, and they were produced way back in 1984, nearly 30 years ago!
The Minelab Vlf's, like the current Eureka Gold and XTerra's, can handle that hotter ground when operated correctly, simply because the designers of these units are ahead of the times and built them to do just that.
You think I'm a Minelab lover and like to bash other detectors?
The SD's and GP's have been so overpriced since their inception, that I still can't believe we bought them. And there's been a few dud models that were badly designed amoung both Minelab Vlf and PI range.
The promise of quietness over the hottest ground, three times the depth, deeper than the previous model ect.
I'm still taking a pre-set ground balance Vlf detector to places that are just too noisy for my GPX!
And I'd much rather buy a brand new Vlf, set it up and work it correctly, than buy a 17 year old SD that's had more owners than I've had socks, and has rusted electronics and screws that nobody can fix)*
So here are my main points on each of them after using all the Vlf's you've mentioned on both hot and dead quiet ground in Victoria. Although you've excluded the best one, I'll mention it anyway.
Gold Bug 11:
3 coil choice of 10x5, 6x4 and 14", all elliptical.
The very high frequency of 70khz alone makes it very shallow searching, unless a larger deeper piece on quiet ground sends it off.
They are beautiful to work over dead quiet ground and on both reef mullock and mullock heaps in general, and scream on tiny pieces of gold.
They are 5/8ths useless on hot ground. See below in the bracketed paragraphs.
Fisher F75ltd:
Around 13khz. Good coil choice.
Much better than I thought they'd be. Really nice to use on dead quiet ground.
Cannot handle hot ground, it upsets them to no end, but due to the lower frequency compared to the higher frequency units they do a bit better at it.
They run a touch better with a big drop in gain. I use that American term for sensitivity simply because you won't Gain much at all dropping the sensitivity so low to be able to run on hot ground. A ridiculously high gain was placed in them.
So overpriced at $1600 It's a mockery though.
See below bracketed paragraphs.
Whites GMT:
50khz, good coil choice for them. Again, great to use on dead quiet ground. Hot ground upsets them.
See below bracketed paragraphs.
Garrett AT Gold:
So much could have been done with this unit, but they just went backwards again. This is not 1985.
See below bracketed paragraphs.
Infinium:
Shocking coil choice, along with shockingly bad coils.
The most badly designed detector made to date, and to think it's still in production, is to me anyway, quite unbelievable.
You must remember, that while it began and still is being marketed as an all rounder with a dive depth of a couple of hundred feet and a new beaut reverse discrimination, they were also marketed here as a full on Gold Detecting unit that could handle hot ground, getting 2 to 3 times the depth of a 'typical Vlf'.
Truth is they weren't as deep as a Minelab gold Vlf run with a big coil in the correct frequency over hot ground, or as sensitive.
*(Welcome to the bracketed area.
This is a place where we can secretly chat about why Whites, Garrett, Tesoro and Fisher haven't bothered to produce a usable gold detector over hot ground. And not just here in Australia either, plenty of bad little patches of hot ground on the goldfields in the States as well.
The engineers that design these detectors are dinosaurs of the industry. Not only can't they come up with step forward in regards to improvement of the units, they can't even keep up with the times.
They are still producing 1980's models of detectors, as that is where they are still stuck in regards to R and D.
Even when designing digital units, they use the same 1980's outlook on Ground Balance, the all important Threshold, and Tone.
They only thing they seem to place any futuristic importance on is a ridiculously silly Boost of Sensitivity.
There are reasons why the AT gold, GMT, Gold Bug's and F75's cannot handle hotter ground. They are designed with really bad Ground Balance and correlation between Balance and Threshold.
There is no way you can work, tweak, operate correctly, tune or whatever words you'd like to use, to get these units to be able to detect deep over hot ground to detect gold.
Why?
Because the designers cannot even match the Ground Balance to Threshold correlation of a Minelab 15000, and they were produced way back in 1984, nearly 30 years ago!
The Minelab Vlf's, like the current Eureka Gold and XTerra's, can handle that hotter ground when operated correctly, simply because the designers of these units are ahead of the times and built them to do just that.
You think I'm a Minelab lover and like to bash other detectors?
The SD's and GP's have been so overpriced since their inception, that I still can't believe we bought them. And there's been a few dud models that were badly designed amoung both Minelab Vlf and PI range.
The promise of quietness over the hottest ground, three times the depth, deeper than the previous model ect.
I'm still taking a pre-set ground balance Vlf detector to places that are just too noisy for my GPX!
And I'd much rather buy a brand new Vlf, set it up and work it correctly, than buy a 17 year old SD that's had more owners than I've had socks, and has rusted electronics and screws that nobody can fix)*