13 replies to this topic

[Rob Allison]

Hello All,

Since the recent price reduction on the Minelab SD's, there has been a lot of talk about the mods and overall performance of them. Over the years, whether you're in Australia or the US, people have stated the SD's still get more outright depth on larger gold nuggets than the GP or GPX series.

I've done some testing over the years and found there is no doubt the GP or GPX series can find small gold and smaller gold at depth over the SD's series. I've missed hundreds of gold nuggets in old patches with the SD's, but keep in mind I didn't have the Pocket Rocket or any type of mods back then (early-mid 90's).

Would like to hear what others have seen, concluded or believe about these two different metal detectors (SD vs. GPX) & technologies.

Very curious myself .....

Rob Allison

[The Shadow]

Since selling my SD2100V2 and getting a GPX4K I believe there is a substantial depth and sensitivity improvement in most spot I hunt anyway. Largely because of the smooth threshold I can get with the 4K at high gains that just could not occur with the 2100. I have found though that some small flat flakes are not detectable with it while a 2200 can hear them barely. Not sure yet why but maybe settings.

[Todd]

I cant speek for the GPX 45k but a SD 2100v2 or SD 2200v2 with a Coiltek Pocket Rocket and a Gold screamer amp and an after market coil, will hold its own on gold bigger than a gram+ as long as you are out away from any EMI. If you have any EMI noise or the gold gets small the GPX4k will smoke the other 2 units. It also has alot to do with the opperators ability. Just look at Unc. Ron and his Baboo.
There are other mods you can do to the other 2 units that will make them compete with the GPX's on small gold, but you will have to deal with the EMI.
The size and type of gold also has a lot to do with it.
The SD unit have probably pulled more Oz's of the yellow stuff outa the ground than all the latter model combined.
For the price you cant beet the SD units.

[Paseclipse]

Hi Rob, very good topic to cover since I've been wondering the same thing for quite a while now because I own and operate both the SD2100 (army green) and a GPX-4000. I've got both machines equipped with Detacc SS enhancers, Coiltek Pocket Rockets, and I use my Black Widow headphones on both models. I've been swinging Minelab PI's for ~2.5 years now successfully hunting meteorites and gold.

From what I've seen and found so far (and I hate to say this) my ancient SD2100 is kicking my 4000's butt on deep gold. The average depth I've been scoring nice sized nuggets is in the 12"-18" depth range with my SD2100 and with my 4000 they're usually right on the surface to 4" deep using an 11" mono coil most of the time on both models. I'd say for sensitivity to small gold the 4000 wins hands down, but for the big deep stuff I go to the SD2100. The 4000 also handles EMI a lot better than the SD2100.

Don't know what it is, maybe it's my confidence level with my SD2100 or maybe I haven't figured out the right settings for deep gold on my 4000. I've spent more time behind my 4000 than the SD2100 and my SD has produced way more gold for me in the short time I've had it (3+ ozt's since August). There has been a few times where the 4000 impressed me (found 8+ oz chunks of Galena 2+ feet deep), but I still have yet to pluck a nice size nugget over 1' deep with it. So as of right now I have yet to see my 4000 outperform my SD2100 on deep nuggets.

Not trying to ruffle any feathers here or anything, just reporting what I've seen and found with both models so far in my short time in the field.

Del

[montana]

For outright depth on large nuggets, my deepest was with the SD2000. For sheer pleasure of operation the 4500 blows it away though. The 4500 ignores far more hotrocks, blacksands, and mineralized ground and can be run with no EMI warble without compromising depth and sensitivity too badly. I feel that I get a better feel for good targets as opposed to trash targets also. I had a blast today with the 4500 in a place that I know would have been tough with an SD or even a 3500. I got over an ounce of beautiful AZ gold in a trasy , hotrock infested gully . The hotrocks were pretty easy to distinguish from a good target with the 4500 and I never heard a wobble of the threshold as the military planes zoomed back and forth overhead at low altitude. ---bob

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[Inhere]

I have had both a good 2000 and a good Extreme for years, I spent a lot of time testing both, in the side of a creek and over natural in ground targets.
In the creek side test the 2000 won by about 1/2," in that ground.

I tested over a quite a few of deep in ground targets down in Victoria, and never found one deep target that both detectors never got. (mostly junk)

On gold in the ground, I believe they will all get about the same depth on a big nugget.

Too much B/S goes on with these detectors! When the 2000 came out there was a lot of big deep nuggets found, because there was a lot of big deep nuggets still in the ground. The 2100/2200 didn't do a bad job of cleaning up most of the rest, so the GP's were made more sensitive to detect the smaller deeper stuff, but there has been heaps of larger deep nuggets found with the Extreme/3000/3500.

Anyone who believes that the 4000/4500 won't go at least as deep on larger nuggets, needs to spend more time with it

[montana]

Inhere. I think you are probably right, in most circumstances there would be little difference in overall depth. With the GPXs your choice of timings could limit depth on certain size nuggets, or increase depth on others, but if run in normal timings there probably isn't a lot of difference on average ground types. The advantage of the GPXs is in the fact that timings choices can improve success on abnormal ground types. ----Bob

[Dutchman]

Can't say much about the GPX series detectors, 'cause I haven't used them myself, but I have found nuggets at several inches so small they wouldn't measure on my scale. My guess is 1/2 grain maybe. Travis and Charlie where there and witnessed me finding one that small. I have also found 1/4 to 2 ounce nuggets at extreme deeps. I hunt with a GP3000 and can't imagine where any improvement can be made on depth or sensitivity. I will upgrade when I am convinced that there is an improvement on depth, but I really don't need anymore sensitivity or my detector will be singing all day on flyshit size minerals.

[Steve Herschbach]

Hi,

Well, I sure found lots of gold with my SD2200 and continued to do so up until this last year. But now that I have the GPX I finally sold the 2200 just a couple months ago. I just really did not see myself ever using again now that I have the GPX-4500.

That said, with the price just lowered on the SD units they have the bang for the buck. With a brand new full warranty SD2200v2 going for under $1800 I can't in good faith tell your average Joe they just have to have a GPX-4500 for five grand. You have to be into your detecting for the GPX to be worth the difference or just have the money to spend.

There is depth and then there is depth. My SD would get a faint hit on hot rocks the GPX will ignore. So I'd just ignore those faint hits, not wanting to dig hundreds of rocks. But of course some were nuggets. The SD saw them but could not separate them from the rock. The GPX can and so while it may not get more actual depth I feel it is getting gold I missed with the SD. And at the end of the day that is what it is about. So it is GPX for me.

Steve Herschbach

[montana]

Steve. My feelings exactly and therein lies the difference. Here's my 2.59 ounces of GPX finds for today. And yes the 2100 would have probably barked at all of them although I might have passed on one of them because it was under a big ironstone boulder. ---Bob

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[Jim P.]

Holy crap Bob! That's awesome! I guess I'll have to cruise on over to Chris' forum to get the story. Thanks for sharing. Later...Jim P.

[montana]

Jim P. Yes there is a story behind these nuggets and it gets even more interesting. ----Bob

[Dutchman]

Bob,

That is an outstanding find I always dig the ironstone hot rocks too. Just for the same reason you did.

[Steve Herschbach]

Nice, Bob. Really nice!

I guess you guys are in prime time hunting mode, while us poor blokes up north just sit and wait out the winter. Thanks for showing.

Steve H