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"Pip Squeek" detectors and more (very long)

A

Anonymous

Guest
Hi All,
A recent post on a prospecting forum has generated some interesting posts including one about "pipsqueek" detectors using AA batteries. The issue was, a PI running on AA batteries can't compete with one using a much larger battery.
Rather than discuss it there, I thought I would bring it over here since it is a PI question as much as anything.
Now, my response to the above statement and competing PI's:
HUH?
Well, for the record, a typical semi can't compete with a Nascar truck either. Yes, the logic is the same. Brute doesn't always mean better. If you think it does, just try to take a semi to the local dragstrip and compete against any of the spunky street cars or trucks that run there on a daily basis. I wouldn't bet on the semi on a quarter mile run. Pick the conditions and Brute doesn't look so good.
Ok, getting back to PI's, again just for the record, I can, with my pipsqueek PI, detect nuggets the "brutes" can't detect. (I do need to point out that I have shortened my delay to be able to detect these nuggets better.) I can detect under power lines that give many of the brutes problems. I can hunt in areas where my PI is very quiet and others are complaining about all the interference. I can hunt in many areas and experience little or no ground response. With a DD coil, I can hunt many of the more mineralized areas also.
What about the other side of the coin? Yes, there are conditions where the brute PI's will outperform mine. Under certain ground conditions, the Brute will be a much smoother operating machine. Is it perfect? Nope, but it can be quieter than a PI without ground balance (GB) because of the ground signals. Add a much bigger coil and the Brute PI will most likely go deeper simply because of the increased flux in the coil. To, there are places and times where the Brute will simply work better.
Ok, now for the power question, itself. Just how important is brute power? Well, I recently built Carl Moreland's Hammerhead (HH) PI and set this one up so I could increase the current significantly. The main limitation was the coil resistance, which, which I do have fairly low at less than 4 ohms. For batteries, I used some special 4/3A's rated at 3800 mah. Total battery voltage was 12V. So, battery power was no problem on the HH. Simply stated, the batteries used would power most of the "brute PIs" with ease. In fact, I would have to lower the voltage for proper operation on most of the Brute PI's. The HH could pulse approximately 5 to 6 times the current my GQ clone is pulsing.
My GQ clone (the pipsqueek) is powered by typical AA's, again 12 Volts. The clone and the HH are now designed to use the same coils, so a coil difference was not a problem. I also increased the gain and made several changes on the HH so it was very close to the my GQ clone in performance (no easy task). Since the HH is a very good basic design, then the idea that the overall design is poor on the HH, isn't correct, so it isn't a factor.
Now, one would think that testing for depth on something as basic as a nickel the HH would clearly show a superior depth advantage simply because of the shear "power " into the same test coil, a 11" DD design. Well, it didn't happen. On the nickel, it was a toss up. Personally, because the GQ is so much quieter, it was easier to hear the signal from the nickel.
Overall, my GQ clone either outperformed or at worse matched the competitor on targets ranging from a 1 grain nugget to a little less than a 1/4 oz nugget. Now, tossing in the fact the GQ clone is so much lighter, I considered the GQ clone to be the clear winner overall.
Why would the GQ clone display such great results? Partly because GQ is quieter do to the overall design and because of using less power. Also, it is partly because of a shorter delay I was able to obtain on the GQ. Now, shortening the delay does two things. It allows my PI to detect objects that others can't see and it provides a much stronger signal with which to work. In other words, sampling sooner increases the receive signal as effectively as does adding more power. In some cases, the advantage may be greater do to secondary effects.
Now, for the record, I have conducted tests against one of the Brutes and have gotten the same results. My GQ clone beat the Brute in some tests and matched it in others under certain ground conditions. Again, the testing was done with similar type and size coils. Change to the right conditions and I am sure the Brute would win.
My point is, what Eric stated on the prospecting forum is correct. Shear power isn't the only factor to consider. Coil design, sampling delay time, and even pulse repition rate are just a few things that can have a large influence on the results. Sometimes pulsing with large currents create bigger problems also. So, overall design because very important.
As for ground balance, any type of GB will result in a subraction of most signals, including the ground signal. This simply reduces the signal available for target detection. Another side effect is increasing the gain of the subtractive signal introduces increased noise which detracts from the net signal also. So, while GB does "quiet" the ground, it does cause problems. I know, I have built a form of GB into my GQ clone.
Since Eric's GQ doesn't have ground balance, and is designed primarily for beach hunting, one shouldn't expect the GQ to match or beat the Brute under the more hostile ground conditons normally found where gold nugget hunting is done. Simply stated, the Brute will most likely win in such areas.
A DD coil will help quite a bit in many areas, but will not cure a severe ground problem, so one shouldn't think the GQ is the perfect alternative. It is lighter, easier to use, and now with the new second filter, will work better, but it still isn't the absolutely perfect machine for nugget hunting.
Reg
 
Reg,
I agree strongly with your observations.
I have tested my GQSS (slow SAT and 10uS) against my old modified SD2000 (sold a few years ago). Well after testing depth capabilities of both units against various GOLD rings and jewellery in a beach environment.......well, the GQSS outgunned the SD2000 on most of these GOLD targets... <img src="/metal/html/smile.gif" border=0 width=15 height=15 alt=":)"> <img src="/metal/html/smile.gif" border=0 width=15 height=15 alt=":)"> <img src="/metal/html/smile.gif" border=0 width=15 height=15 alt=":)">
The SD2000 had a depth advantage on our coins, but that is of no consequence to me as I'm after the good stuff.
Tony. <IMG SRC="/metal/html/ausflag.jpg" BORDER=0 width=32 height=17 ALT="au~">
 
Hi Reg:
Thanks for the interesting and educational post.
I want to assure you that the rest of the members of that prospecting forum do not necessarily share Bob's "MORE POWER" view of things. Power is an element in how a detector performs, but only one small part of it. I hope you dont mind, but I reposted a quote of your comments and a link to this thread so the rest of the prospecting forum can read.
Chris Ralph
"Reno Chris"
 
I think Potholes Bob was looking in the mirror when he suddenly thought up the name "Pip Squeek" <img src="/metal/html/lol.gif" border=0 width=15 height=15 alt=":lol">
 
Reg, I really enjoyed reading your post, and found it to be both interesting and informative.
The purpose of my post was to encourage forum participants in Bill Southern,s www.nuggetshooter.com
to post their ideas and experiences regarding an improved, or "souped up" Minelab SD...2100, and also the 2200.
I used the term "pipsqueek detector" when I was attempting to help an obviously non technical forum member understand the power difference between 13 volts at fifty milliamperes and 13 vots at one ampere. In the same post, I also used the example...."Could you use eight AA batteries to start your truck engine? Why not, eight AA cells produce 13 volts also, the same as a 13 volt high amperage lead acid starter battery! <img src="/metal/html/lol.gif" border=0 width=15 height=15 alt=":lol"> I intended the Term "Pipsqueek Detector" to be "provocative", and hoped that it would tempt. some technical folks to post. Apperently, I was correct, and was delighted to see Eric Foster post a very interesting piece on the PI detector! I realize that although most of you are interested in coin shooting, as I am, you have a great deal to offer us with your technical back grounds, on the prospecting forums, and I do hope that you will visit us and give us your input on technical matters!
Incidently, Bill Southern keeps Reg Sniff's Bench Mark article "on understanding the Pulse Induction Detector, permanently on his web site, it is the best all around article of its type that I have read!
Warm Regards
"Potholes" Bob Martinez / W6PU
 
Arizona flash...One of my favorite sayings is, If you can't listen to yourself talk, and occasionally laugh at yourself, then you are in trouble! <img src="/metal/html/lol.gif" border=0 width=15 height=15 alt=":lol">
Potholes
 
It's ok PH Bob you're a mental gaint!!! <img src="/metal/html/lol.gif" border=0 width=15 height=15 alt=":lol">
 
Hi Bob,
It is becoming more difficult to think of new names for PI detectors, so I will keep <FONT COLOR="#ff0000">Pi</FONT>p <FONT COLOR="#ff0000">Squeek</FONT> in mind for any future development that uses AA, AAA, or PP3 batteries. Very clever, as it incorporates both the principle and the sound it gives. Trust it is not copyright <img src="/metal/html/biggrin.gif" border=0 width=15 height=15 alt=":D">
Eric.
 
Hey Tony , have you had much success using the GQ for nuggets or are you talking about rings etc.
Regards tj
 
Hi Kev,
The forum was the Nuggetshooter forum. Hopefully, the link below will take you to it. Once there, the thread was the one about 'Hotter detector than the GP's'.
Reg
 
TJ,
My hunting with the GQ is strictly limited to the beach/water. I'm looking for gold/platinum/silver jewellery.
The goldfields over here (I am in Western Australia) do require a detector with some form of ground balancing/cancelling.
The ironstone laterite is like "nothing else on earth", with marble sized pieces able to easily "jump" onto a regular magnet !! <img src="/metal/html/oh.gif" border=0 width=15 height=15 alt=":O"> <img src="/metal/html/oh.gif" border=0 width=15 height=15 alt=":O">
Having said that, I have experimented in that sort of ground with the GQ by burying a large gold ring and being able to detect it at about 4" deep. I HAD to reduce the delay to around 40uS, ensure SAT was at fast, and then sweep the coil about 4" off the ground at a VERY regular height. Even though there was still a fair amount of ground noise, the audio response from the ring was clear and unmistakable.
So, if you want to find decent sized nuggets (of which Western Australia is famous for), then the current GQSS will find them. A GB detector would be my first choice though. I'd guess and say that nuggets over half an ounce "should" be detected.
Here's some "Tough Ground".....Ironstone laterite. <img src="/metal/html/cry.gif" border=0 width=40 height=15 alt=":cry"> It's actually the pathway down the side of my house. Worse ground is with a hard clay compacting the loose stones together.
Regards,
Tony. <IMG SRC="/metal/html/ausflag.jpg" BORDER=0 width=32 height=17 ALT="au~">
 
Hi Tony
You certainly have nasty ground there. A couple of points to ponder over. You may want to change over to a widescan coil, (DD). It would require a bit of re-wiring both on the circuit board, and your coils. Not hard to do if you have some experience working with electronics.
The new additional filter circuit we are now using in the Goldquest SS V.2 certainly would help. Again, it’s something that could be added to your unit. I’m not suggesting that this would put a end to all those problems, but it certainly would help.
Depending on your beach conditions it may improve things there also. <img src="/metal/html/shrug.gif" border=0 width=37 height=15 alt=":shrug">
Mr. Bill
 
Hi Tony,
Geez, looks like someone working in an old marble factory went to work drunk. That stuff looks pretty ugly. I have never seen anything quite like it over here.
I don't suppose I could possibly pay you to box some up and send it to me? That way I would have a better idea of what you guys are up against.
Reg
 
I think that would be a great name for a detector Eric, also, how about "The Mighty Mouse"? <img src="/metal/html/lol.gif" border=0 width=15 height=15 alt=":lol">
Potholes Bob <img src="/metal/html/wink.gif" border=0 width=15 height=15 alt=";)">
 
Mr.Bill,
Thanks for those ideas. Although I don't detect for gold nuggets much, I'd be curious to know how the GQSS would perform with those changes....
Thanks,
Tony.
 
Reg,
No problems with doing that...
How much material would you need ??
I have good contacts with Fedex and DHL, although regular Australia Post might be cheaper.
The bad ground that we have over here contains plenty of what you see in the picture, but is cemented together with a hard clay (depending on rain). Do you think the TX strength would be less affected by a loose material only (as the picture shows)?
Tony.
 
Hi Tony,
I am not sure whether loose rock or gravel will generate as bad of a response as a clay and rock combination. I am inclined to think the clay and rock could be the worst of the two under the right conditons. If the combination is the right mix, I would think the rock/clay combination could produce the strongest and widest signal variations which could easily mask a deep nugget signal.
As for the amount of laterite sample I could use, I would love to have enough to build a nice test large bed, but that is not practical. So, I have to try to get enough to sufficiently produce a decent signal as large as a typical coil. One way to try to determine whether the rock or a clay/rock combination is the worse is to simply test them.
So, what I am thinking is maybe two boxes, one filled with the rock such as in the pic you posted, and a second one filled with the clay/rock combination such as found in the field. What I am thinking for box size is something about the same size as one used for priority mail supplied by our US postal system. They are about 12" by 15" by 3". If completely full, they should be enough for basic testing, I would think.
Does this sound unreasonable?
Just let me know the general cost and I will be happy to ship the money before you send the material. If you have a paypal account, I can make a quick transfer also.
Reg
 
Reg,
I will get a rough idea of what one of those boxes will cost to send to the US. At this stage, I can send a box of the "ironstone marbles" but I don't have ready access to some heavy mineralised clay base such as is found on the goldfields 600km away.
Leave it with me and I'll keep you posted.
Tony.
 
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