bklein

I’m liking the Manticore but the lack of good targets is bumming me out. If there were some I could desensitize it to the junk and a much more fun day. The real good sounding stuff are cans and rusty pipes 1.5 feet deep, surrounded by rocks. In the wet, too deep to get, again in rocks with sand that continues to cover the scoop hole just dug. I don’t seem to be able to locate targets as well as I can with the CTX, just need more time and better conditions - or just hunt the dry. Thus, this is the time to learn the machine and experiment.

I posted this video on another thread but this one seems more appropriate, we were talking of starting one on this topic. In this video the manticore failed on a nickel. I tried several settings and had no added discrimination - only the stock iron settings in effect. The thing is that this was heavy black sand concentrate. I went back the next day and filled a 5 lb bucket with not as black sand from an area a few blocks up the beach, brought it home, put it in a plastic cement mix tray and the manticore did just fine - I could not duplicate the video. The AQ did exactly the same. I did not have my Manticore with me to test the second site sand before taking it. So yeah beat me up for not recording exact settings etc. Thing is that the video is not edited, my first take, I did not know what to expect. My friend came by and tested his manticore on an area maybe 15 feet away and had no issue. I don’t think there is a difference between his and my detector - I think it is a dependency on the ferrous content. We both walked towards the water and started hitting targets and compared responses between us - same numbers/strengths. We see black sand and yes, often there are good targets beneath it, but perhaps if the concentration is too high we miss them. This is not just a Manticore thing. Seen video of it happening with an eq800. So I hope others do some experimenting MC vs PI in black sand. Try my nickel test next time you run across sand like this. I screwed up my back carrying the damn bucket. I bought a bag of black ferrous material and may just mix it in with my sand to test.

I was focusing on a Bigfoot for a PI detector. Worked great on a GP extreme. Maybe all the gotchas are only true with a vlf?

Ok so I start a new topic that would regurgitate some of this one?

How should we proceed? I find the discussions interesting and would like to see and do more testing along these lines.

Big honkin’ wire on the black original! What would be the result if you were to make a cutout the diameter of the piezo in the backplate? (Ignore waterproof aspects) Guess I’ll have to play with them. Sorry to ask again but what is the goop covering the piezos in the photos? Does the thickness or coverage affect results?

Anyone take apart the stock headset? Cheapest route would be to modify it. Those MSA L/R’s are like $60 to begin with, Tony made nice replacement piezo plates. What he is charging for his headset is probably reasonable given the background work he had to do to come up with a product. I wonder what the high efficiency mod is. Good to know it’s right to get for the AQ. I just received the 50mm black rimmed piezos today. I’m just not that anxious to start this project… might just buy Tony’s and do mine later. OBN, you said Alexandre uses a JBL Clip for his demo. So he uses it as an amplified speaker (not Bluetooth)?

I believe it was set to 4.

Not sure what you mean by iron reactivity settings - but the iron settings were default and no added discrimination masking. Yeah, funny that the Carrot found the nickel just fine. But is the Carrot a PI design? What do you think of my experiment running in discriminate with higher sensitivity? The nickel is not giving me an iron signature - it’s not seen at all (unless within an inch of the coil). If I was an engineer at Minelab this would be a challenge I’d love to take on. Must be a way for MC coil and electronics to function better in this concentration sand?

I’m sorry I’m not sure of the settings in the video. I usually ran deep or LC mode and prospecting audio but during my time testing seen for the video not sure. If all metal the sensitivity was likely like 23. But towards the end I thought I’d see what would result if I ran in discriminate with Sensitivity cranked to 31. I was thinking if the detector has any ability to pick out a non-ferrous target (the nickel) from the black sand I’d be masking the iron and be more sensitive to everything else. That resulted in short random tones that you hear. Not enough of them to overload my brain. I went back and got a bucket of sand yesterday with my wife’s complete disapproval. She was pissed - wanted us to walk our dogs. This next day I was at an area a few blocks north and the sand was different - not as many black sand concentrations. My friend also went back yesterday and found more targets than the day before, perhaps because the black sand wasn’t as concentrated. One of these days I’ll get around to making a dual mic setup so I can narrate while the detector audio can be heard as well. I had seen a video by Fun With Jim showing the masking (Equinox 800) of coins by the dry black sands at Sunset beach, perhaps 5 miles north. He seems to get good targets there regardless. My goal is to eventually get a home test platform in a concrete mixing pan so I can test several detectors.

Just got depressed using my Manticore in black sand at Newport Beach. Put a nickel on top of the sand and detect it probably >15”, depress an area 1-2” down from surface and it only sounds if the coil is an inch or so from it. I tried all modes. Sorry I didn’t have my AQ to see how it would perform.

Yes that’s it, but I just powered the detector and it’s in deep not LC so now I need to retest to verify….

I think I was running configured as you guys are suggesting: beach LC, prospecting mode. I dug a hole in the wet and dropped my gold ring on a string into it - digging the hole deeper and repeating to test depth. It would become a still rather strong ferrous target - which the manual suggests may happen. I didn’t try/toggle the ferrous tone function - I’ll try that today. Just saying if you are running like this, dig the ferrous targets.

OBN, I called PUI tech support regarding the "50mm" discs with black plastic ring. He came up with this one: (48MM): https://puiaudio.com/search?query=aps4812b-lw100-r Is this what you used?

I just tested detection depth on a gold ring in the wet at probably 15” with my new xxxxxxx. Yes it turned to a ferrous target - but a loud one that I’d dig. My AQ probably would hit it, my modified White’s machines maybe. If you hunt in the surf though (here in so CA) you wouldn’t want to risk the AQ in the surf as they are pretty fragile. You don’t need or want extreme depth as you can’t dig a hole deep enough in time to get the target. So I’d advise not spending big bucks. Your Sand Shark has about the smallest profile of the detectors Steve listed. Might still be the best for you and worth fixing.

I emailed Tony and he has two options now for his headphones: One is adding drain holes for guys that really soak them underwater. Drains easier. Second is an "high efficiency" option that results in more volume. Stalker, do you have any thoughts on these options? Is the AQ audio drive intended only for piezo loads?

Here on soCAL beaches, a while back there was a guy that drilled holes in penny’s and distributed them around the shores. I think he got caught doing it once. I’ve met him a few times but never discussed this topic. He and another guy got in a pretty bad way about it. I never heard what his purpose was for sure but I imagine it was to track coin movement. Now this year someone is cutting penny’s in half and spreading them at several beaches. Same purpose? Anyway one thing about getting coins is I’d think it’s a sign that gold may be nearby, like if you find lead sinkers. Also a sign that it’s working well. With a CTX it’s the sweet sound of a nickel. With the AQ I haven’t found enough targets or tried it enough times to remember the sound of a gold ring jumping out at me.

Anyone tried these? https://www.steminc.com/PZT/en/multilayer-piezoelectric-speaker-700-hz https://om.rsdelivers.com/product/sonitron/sps-3530-03-c1/sonitron-piezoelectric-miniature-speaker-81db-700/7868917 I am also wondering about your link for the black ringed piezo. It doesn’t show the ring in the photos.

Continuing, the Equinox series and Manticore have all these settings for ferrous/iron this or that. CTX doesn’t - or at least simplifies it. For beach hunting (I’m generalizing) just not a real factor for me. Maybe they could improve performance in black sand - but it likely could be one additional “black sand” check box to set. As far as the battery goes, I have one that I upgraded the cells on. It goes for hours and hours - I never have found out how many. The thing is it charges really fast. Much faster than say my EQ600 or Manticore. (The WM10 takes much longer.) I could have used just two cells and replicated normal duration with half the weight. The CTX is missing the Prospecting mode and the higher Sensitivity capability. Wish it had it. There is a balance between the Volume Limit and Sensitivity. The CTX recommends a Sensitivity setting but it is always lower than I set. You can run in Auto and forget about it depending on conditions (I don’t). The others don’t help you out in this regard. If they did there would be less returns and happier first time users. My CTX ground balance is set on Auto and I haven’t touched it in years. My Manticore changes GB on mode change and I didn’t realize it so it ran like that and was a pain. The NC on the CTX doesn’t work well and rarely repeats the recommended number if done repetitively. It works great on the MC. So firmware upgrade, lighter coils, EQ housing/shaft concept…. Or just a firmware option for the Manticore?

So why doesn’t the CTX get as outrageously noisy like the Manticore and Equinox if the Sensitivity is maxed out? I often run mine full out. I set the volume limit back some to reduce the small trash targets (beach) but it seems either the CTX could have more Sensitivity/gain or the MC/EQ could use the volume limit function.

Ah no, you can’t escape that easily! Give us details on build details!

Hold out for the third edition of Carl Moreland’s Inside the Metal Detector (ITMD) book hopefully early 2024. (Discussed on Geotech) it will have new content since the earlier versions. I hope you try a Bigfoot type for the Impulse AQ or Dual Field.

Any diy’r try one of these on a PI, Equinox, CTX, or Manticore? The last 3 require a board from an old coil to satisfy the security chip requirement. PI would be an Impulse AQ.

Doesn’t the CTX have the heaviest coil set? A Pro harness can take the detector weight off you but the swing mass still is a killer. If they came out with a new line of lightweight coils…. I did the work of taking out a board from a damaged coil, now I’m not sure what coil could adapt to it. Wondering if one of the Detec Arrows would be good? Is its weight a problem too?

Great info, thanks! So that’s the Heyco to get…. Been wondering on that for years. You have an impressive ability in not only making things but researching the market for products and solutions.