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GA1dad
02-08-2015, 05:31 PM
I've been needing to make a test plot of some sort every since I bought a detector. In my mind an air test will only be so accurate. So today I finally got it going. I wanted to be able to use different soil types, hence the divider. One inch PVC will allow up to quarter sized objects. Hopefully this will give me some better reference of what good targets will sound like in the soil.

Ill Digger
02-08-2015, 06:02 PM
Some serious thought went into this design. :yes:
This is probably the nicest , most versatile test garden I've seen on the forums!
It should provide you with the simulated situations your looking for.
You could even slide some junk targets in the tubes with your coin.
Your just gonna want to make sure that there's no rebar, or conduit in or under the concrete, or floor that your test garden is sitting on.

Lodge Scent
02-08-2015, 06:24 PM
Nice bit of craftsmanship there :perfect10:. I just might have to steal that design for my own test box :thumbsup02: The only mod I might make is to make a sleeve big enough for a big rusty old ox shoe.;)

Fire Fighter 43
02-08-2015, 07:18 PM
Nicely done, good luck with your test.

GA1dad
02-08-2015, 08:04 PM
Thanks for the compliments. A uni-bit ( or step drill ) made everything quick and easy.

I filled up one side with the dirt I snagged from the park this morning. I then slid a mercury dime in the 4 inch slot. Imagine my horror when the Platinum wouldn't register the silver dime at 4 inches. I bumped up the sensitivity and was able to detect it,,,,, even when there was no dime to detect. Hmm,,, not good.

Then I grabbed the Ace 350 and it wouldn't sound off at 4 inches either. Raised the sensitivity up to one notch below max and it finally sounded off.

I don't know what this stuff is,,, but man it's brutal. I'm beginning to think maybe it wasn't that gray sandy soil from the park, but instead may be the base material you put down before paving a road. It got dark on me. I'll keep fooling with it.

GA1dad
02-11-2015, 09:52 PM
All I wanted was to do some testing in a plot similar to the old local park,,,,

After my first unsuccessful attempt using the test plot, I was highly unsure if it was machines or mineralization that caused the failure. But how would I decide on the culprit? On the surface, my first option was to try different soil.

Option number two - I had a fellow detector come by with his AT Gold and Etrac this afternoon. Again, my goal was to determine whether it was my machines that were the issue, or the soil.

First up was the AT Gold. It ground balanced at 70, which was very close to what my Platinum read. The AT Gold read the Merc at 4" inches, but sounded pretty deep to me ( weak ). At six inches it wouldn't hit consistent, and the numbers were heavily skewed. The owner of the machine admitted that he would not have dug the signal.

The Etrac had similar results, but did make it down to 8 inches before losing the signal. The numbers were all over the place after 4 inches though,,, and again the owner stated he wouldn't have dug the signal. The owner added that he was very surprised how poorly the Etrac performed in the test soil.

So now I do at least feel a little better. If his mid and upper level detectors were affected by the highly mineralized soil, it would certainly affect my entry level machines. Moving forward, I think I will go and dig some test holes at the park and test for ground balance to be sure I am comparing apples to apples.

Am I making it too complicated? Maybe, but I'm thinking there is some usable learning in here somewhere,,,,,

GA1dad
02-12-2015, 08:08 PM
You tenured folks might be laughing at the newb,,, but thanks for your patience.

Well I made some headway this evening. My family was out when I got home, so I had more than 5 minutes to play. After a few minutes, I began getting some consistency out of the Ace 350 in coins mode at 5 inches, though the depth indicator was maxed out. This is PROGRESS!! Then I bumped it up to 6 inches and it sounded off, but not as consistent. That's okay I thought,,, 6 inches on a thin Merc would be respectable for my entry level machines. The test box showed me what I needed to know,,,,, forget about using the BH Platinum in the old park. Then on a whim I tried the 350 at 7 inches,,, and it was still giving an occasion high tone,,, but more importantly, I think it revealed a "tell". I noticed that while it gave the high tone associated with silver, the target ID was not consistently showing me anything. And when it did id, it would only stay showing for a millisecond. I had never seen this before. Additionally, even though the target ID would only show maybe one out of four swings/tones, every time it did show it was showing a dime. That combination of maxed out depth, high tone and no consistent target ID just might be my ticket for ID'ing a deep silver.

As you've all said,,, learn your machine.

MangoAve
02-12-2015, 08:30 PM
Weird. The 350 operates at a higher frequency which should be more susceptible to the mineralization. It's not much, 8.25khz vs 7.8khz of the platinum. Maybe it's the coils if you got the new 350 with the 8.5x11 DD Cuz the BH is prob the round altho there was a possibility to get the 11" DD. I haven't seen many Dimes below 5 or 6 inches altho I know my machine goes 7 or 8 on dimes. And yes it's all about learning your machine. Just learned tonight my new DD actually will read quarters like zincolns, when they are near bent iron such as a zinc coated iron L bracket but is repeatable. The stock 8" wouldn't read it. However, know the numbers for coins by themselves didn't change with the DD.

GA1dad
02-12-2015, 08:59 PM
Yep,,, 8.5x11 on the 350 and the 8" concentric on the Platinum.

del
02-13-2015, 06:38 PM
Its a great looking test "tank" GA1dad , very nicely done !