Jump to content
Nugget Shooter Forums

Anyone Care to Quantify "Low and Slow"


Recommended Posts

OK, another SLNugget silly question. ) I read and hear experienced detectorist tell newbie's to go "low and slow" when swinging their detectors. I think I have the low part understood. Basically just lightly touching the ground, right? Is there anyway to quantify the "slow" part? How much time to cover say 3 ft in one direction? Any good videos showing the correct technique(s). Any info would be appreciated. Thanks,

Stan

Link to post
Share on other sites

I've only been detecting a little over 4 yrs, but I think of it like this,...

Imagine being blind, in a new room where you've never been.

You use a cane to "feel" your way around, at a safe speed and in a patern

that allows you to cover the whole area.

Or, how about 2 sec per 2' sweep, moving ahead 1 ft with each sweep.

That's 4 square ft. in 4 seconds.

That's not particularly fast or slow. You may want to go a little slower until

you get the "feel" for a sweep and an "ear" to distinguish tones of sound.

I practiced on silver coins, copper pennies, small gold pickers taped onto

a guitar pick, and roofing nails. Just toss 'em over my shoulder, out in the lawn,

turn around and go fetch.

You can learn the dif sounds, how close or far you are from the item when you

pick up signal, and how the signal differs for each metal.

I feel like I'm sneakin' up on the target, don't wanna scare it off.

Don't rush, if ya wanna hurry, take up joggin'. LOL

Most of all, have fun, 'cause it is.

Link to post
Share on other sites

Stan there may be a video out on it I don't know but the best way to completely understand this is by being with someone that can show you.

I will tell you this no bull, there have been many targets, usually GOOD ONES (gold) especially that I would have or DID miss hearing untill I made a second pass very slow and dragging my coil along the ground that is when a definite response was heard.

Some of these targets are right at the edge of the coils capability per depth and or size.

Other instances are a combined factor of the coils ability AND ground mineralization AND signal producing hot rocks or junk targets all close together and seen by the pass of the coil in a given situation.

I was out yesterday and detected a bank on a slope where nuggets were found in the wash that the slope led into and this exact situation happened. The 1st pass I made was an average swing speed then I went back over the exact area with a ground dragging SLOW sweep and a definate target response was hear(produced). A tiny nugget was recovered from amoung hot ground, hot rocks and at a depth of approx. 8 inches. A .4 10ths of a gram or .3 dwt. size piece.

That SLOW coverage swing at that exact moment saved me from getting the skunk Sunday hunting.

  • Like 1
Link to post
Share on other sites

"Low," is easy. Like you said, as low to the ground as you can - I scrape it with my scuff plate. "Slow," means that your FORWARD progress is slow enough that you are OVERLAPPING your swings, and not missing 2"-10" swaths of ground as you swing back and forth. It is unnatural and takes time to learn – like rubbing your stomach and patting your head at the same time. I grid the beach just like I do a nugget patch, east to west, then north to south. I take one half-step forward for every two swings – Left, right, half step, left, right, half step.. Patience and practice is all it takes.

Link to post
Share on other sites

Dang Terry, Small enough font??? Had to get out the wife's reading glasses. :ROFL: When are you heading back west? Hope to run into you this season.

  • Like 1
Link to post
Share on other sites

Got me thinking. I use a moderate swing when just seeking a place, When I know nuggets are in my spot I do go very slow, I would guess a full swing round trip may take about 5-6 seconds. But not that many places I can hunt is a full swing practical to get around manzanita or other bushes. Definitely one small step at a time and not anywhere close to a walk.

Link to post
Share on other sites

Thanks for the replies everyone. Good tip on gluing a small piece to a guitar pick, SP. I am gonna make an effort to get out and practice more often. There are a couple of tailing piles over in central WA that I want to check out. And of course the area surrounding the old mines is intriguing.

Stan

Link to post
Share on other sites

Stan If you can make it to the Nugget shooter outing in October... You will learn more in a weekend than you could in a year (or more) on your own... Not from me mind you. Lol. But some of these guys and gals are the best "Nugget Shooters" on the planet... And simply observing and listening to BS around the bonfire is a better education than any amount of money can buy... See ya out there someday.

Link to post
Share on other sites

Slow, slow slow! Like you were making love to your wife for the first time! Make it last, Slow and easy! Ha! Ha! Grubstake

Learn all the good spots.

Link to post
Share on other sites

In regard to nugget hunting with a GB2, I scuff the ground whenever I can (meaning no sharp stones sticking up, no brush in the way and preferably loose, spoil such as one finds in old tailing piles). I use a very fast swing in NORMAL mode for most of the time until I get a zippy response. It seems to induce a stronger response. But I slow way down when in AUDIO BOOST -- almost to a crawl. This is reserved for the faintest of signals (little pieces of gold sometimes embedded inside a small clay ball and as little as .01g or smaller).

Link to post
Share on other sites

Micro ... Yah, the GB2 does like a good whipping action when you're crumbing ... It does seem to enhance the signal, provided your coil is scrubbing the dirt ... I always switch to disc when I get a hint of a target ... GB2 gives a definite gold response in disc, distinct even from birdshot ... Cheers, UNc

Link to post
Share on other sites

Sweep speed is dependent on the machine, you can do bench tests to see how slow or fast behaves on your machine. Mine vary a lot one model to the next.

Scan width depends on the coil. An inch or two less than the coil's width should cover the most ground, but the deepest area is maybe half to two-thirds of coil width. This no doubt varies a lot by coil size and design.

Swing distance is what's comfortable for you. A really narrow swing can help as much or more than a snail-crawl speed normal width swing.

-Ed

Link to post
Share on other sites

I use a Minelab PI machine most of the time. Currently it is the GPX5000 ... swing speed for the detector is critical and variable ... and over lap differs greatly depending on using the mono vs. the double D coil. Remember that the mono transmit signal is like a cone in that the deeper you detect the smaller the area covered. Picture an old fashion ice cream cone ... lots of ice cream at the top (lots of ground coverage) and very little ice cream in the point at the bottom (very little ground covered). That point is in the middle of the coil so an overlap of 50% of the heel to toe distance of the coil is the minimum. The double D is a little different in that it is more like a knife blade heel to toe of the coil so overlap is not as critical but again necessary to cover all the soil area. In my case I overlap about 20% of the heel to toe distance when using the double D coil. As for speed it varies from slow to slower. For practise if you use the old "One thousand One, One thousand Two, One Thousand Three" rule for counting seconds your 3 foot swing should be about 3 seconds in one direction or 1 second per foot of swing when just searching for a patch or a target signal. Once you get the target signal slow and slower comes into effect ... meaning the swing speed could be 2 to 3 seconds per foot or even less if the signal is very faint. One caveat on the very slow constant swing over faint targets ... be sure you are in fixed ground balance so you don't balance out the target.

Hope that is clear as mud.:)

Mike F

  • Like 1
Link to post
Share on other sites

Thanks for the additional posts and info. I guess I should have said I am using a GB Pro. I have the 5 inch and 11 inch coils for it.

Adam, I figure if you get enough headaches there may be some nugs left at LSD for us rookies to stumble across. :rolleyes:

Stan

Link to post
Share on other sites

Dang Terry, Small enough font??? Had to get out the wife's reading glasses. :ROFL: When are you heading back west? Hope to run into you this season.

Sorry 'bout that! Looks like Bill fixed it. I sure hope to get out to Arizona soon. It would be good to hook up with my Brother and Sister in Glendale. Unfortunately, business here in New York is keeping me on a very short leash for the time being. Maybe September 20th or so.

Link to post
Share on other sites
  • 2 weeks later...

Ed in SoDak gave the best generic response. What he also said was very critical and that is, ideal sweep speed is detector dependent.

Some VLF's work better when they are moved faster and the only way to know for sure is to some serious testing. The best approach is to use a very small target, preferably a non ferrous one.

Next, bury the target. Yes, you can get an idea in an air test, but the in ground test also takes in other factors that are not easy to explain.

PI's are different. Because an extra amount of filtering is used on a PI, the sweep speed is more critical for more reasons than one. Also, on PI's such as the newer ML's, the programs change factors than can influence that sweep speed, so again, the best technique is to do a little experimenting.

The TDI is also very speed dependent and again, the ideal target is a very small piece of gold or other non ferrous object. Sweep too fast and small gold will be missed. The reason is actually reasons. One, the filtering is such that it has a peak at a certain speed. This varies a little between the TDI and the TDI pro because of a slight filter difference. The second has to do with the circuitry that eliminates half of the wee-woo response. Remember, on the TDI, the audio is either a wee or a woo. The corresponding second part of the wee-woo or the woo-wee is eliminated and filtering is involved. Sweep too fast and this filtering becomes an issue.

Since most people use a Mono type coil on the TDI, the determination of the ideal sweep speed is quite constant. However, switching or using a DD coil does alter this ideal sweep speed.

As for the "cone" theory on a mono, you might be surprised if you actually try to determine any front to back width between a mono and a DD. If you think about it, why would the transmit signal strength differ between the DD and the mono in terms of the theoretical field structure.

Now, side to side or width of detection does change between a mono and a DD. This width difference also has a large effect on the ideal sweep speed. Experiment with it and you will see for yourself.

One last note, too fast of a sweep speed has another serious problem on the ML. Swing over a shallow piece of iron trash and see how long the target signal lingers. While it is lingering, the ground covered is basically not detected for weaker signals since the stronger iron signal is still dominating.

The two basic factors to determine the ideal sweep speed is to experiment and using common sense. Slow and fast are relative terms. A good example is fast to a nascar driver is not the same it is to the 75 year old neighbor driver. BTW, slow isn't the same for the two drivers mentioned.

Both types of drivers require practice and experience if they are going to do the best they can. The same holds true for people using detectors.

Reg

Link to post
Share on other sites

Here are two quick points regarding ML sweep speed:

1. When EMI is bad to horrible, by slowing WAAAAY down [approximately one foot per second or less] one can clearly distinguish a target despite all the crackling and chatter caused, for example, by a nearby lightning storm. This is so because all of the EMI I have ever heard is sharp, crackly, short in duration and never repeatable, while a target such as a nugget, emits a much more continuous and much purer high-low or low-high sound. Next time you are experiencing a lot of EMI that you cannot seem to filter out, take out a small test nugget and compare the difference in the sound duration between a fast sweep and a slow sweep. Memorize that longish, lazy but repeatable wave of sound even though it may be very, very faint. It will be your ticket to more nugget recoveries.

2. Regarding long buried small metallic objects that have created a halo and give off a very, very faint signal -- as soon as you disturb the ground by scraping it with a pick or with your boot, sometimes the signal mysteriously disappears. It's like popping an electromagnetic bubble. In case the source metal is a small gold nugget continue to sweep your coil over the mysterious Steven King Spot but slow way down as you scalp off surface material. You may again pick up an ultra faint response. I generally mark these spots if i still can't find the target and come back later with my GB2.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...