Results of last week's 4kHz trial hunts...

[CZconnoisseur]

So I've been having some success with using 4 kHz in trashy areas, most notably at the fairgrounds site. The first two pictures is the result of the first hunt at the roller coaster area using the 4 kHz program. Didn't find any bottlecaps in the 2 hours I was there at that trip which was refreshing, and the number of iffy signals seems to have reduced while using this program. The silver medal is likely from an Army dress uniform, and is from the 301st Regiment probably WWII era. This medal sounded off and locked in at "85" and was only 2" deep, so in 8 kHz on previous visit, it sounded exactly like a bottlecap to me. I switched to 8 kHz and scanned the medal, it came in at "91" which is where those pesky caps like to register most times!!! Also found a nice 1920 Wheat which came in at "61", and I think I may have notched it out on previous trips since in 8 kHz it reads as "70" - the highest notch value for that program. I don't have any mid-level notching for the 4 kHz program as I try to listen to the signal and read the VDI stability (when applicable) to determine if I want to go after the target. I've found a ton of old brass lightbulb bases near the old coaster, and in previous hunts those were notched out - but I also notched older Wheats and possibly some Indians in the process

The next night I was worn out from not sleeping, so I did a quickie 45-minute hunt next door at a vacant rental house I've detected before. Using 4 kHz I went to the front yard and got a squirrelly "75-80" VDI but the signal was fairly strong, and dug out a worn 1924 Merc around 4" deep. I then stayed in a 20' x 20' imaginary box and took my time in this tiny area looking for masked coins. Managed to get a 1953 Wheat and three other pennies before I gave up for the night

The next set of pictures is from last night's 4-hour long concentration at another end of the roller coaster area that I've hit pretty hard with the Deus already. Almost right off the bat I got a strong "61" which turned out to be a 1936 Wheat 5" deep. This signal had a steady VDI and there was no trash around the target. Probably a target I notched out previously - but who knows...Went on for another 30 minutes, digging a couple of nice-sounding cast-aluminum trash, which always gives a good audio signal especially if it's deep. There's no way I know of around deep cast aluminum, just one of the perks of visiting the site I guess! 4 kHz really sings on this stuff, but given the age of the place and the potential, I don't mind finding some trash like this. The large aluminum washer really had me going - it rang up at "89" and was 9" deep , and I really thought I had another silver half, even when I spotted the edge of the washer I thought I had a keeper :veryangry:
Got a couple deep clad quarters around 6-7" which rang up at "83-84" solidly, just mild disappointment that they weren't silver, but at least they are spendable coins nonetheless! The Merc was a little unusual - initially I got a "72" but sweeping 90 degrees it changed to "78". Dug down to find a rotten wooden 2 x 4 eight inches deep with a few nails poking out of it. Reswept the area and the target was still there, indicating a solid "77" both ways. Propointer had it in the sidewall, about 6" deep, and a quick flick of the Lesche dislodged the Merc, which was beat up and scratched before I touched it.
Not pictured were a few large iron objects that bled through, one was a nut almost as large as a baseball that I recovered from about 12" deep. At this depth iron will still sound good in 4 kHz, but switch to other frequencies and it will sound even better unfortunately. The VDI in this case went DOWN, the same as a bottlecap would, when switching to 8 or 12K; but I dug it anyway to get a feel for the program. I also found a large 8" long spike, and upon rescanning the area, there was a clearer signal in close proximity which turned out to be a high-relief Memorial - illustrating the masking effect of large iron over coins at this site.

The last picture is from the last rental-house permission hunt I did early last week. I used a 12 kHz program with Reac = 3 and Silencer = 0 and spent about 2 hours searching close to half the front yard. Found the lovely 1937 S Merc and 11 Wheats, which is a personal record for # of Wheats in a single hunt. The renter wanted to give a couple of Wheats to his kids, which I had no problem with!

Next hunt will be another permission hunt on a 130-year old homestead. I can't wait to get out into the country and lower the Reactivity, raise the Sens, and see what the Deus can sniff out - should be a virgin site and I have the entire day (when the Sun is overhead! Not a night hunt!) set aside for this....can't wait! Should be a great area for the new 4 kHz program!

Now that I've had about 8 hours total using only the 4 kHz program; I feel that it runs a little quieter and more stably than the 8 and 12 K programs I'm more accustomed to.

 

[parkgt]

Great report and some neat finds. I have always wondered why more Deus coin hunters don't use 4kHz more. When I got my Dues it seemed that most were using 12 kHz programs with a few running 8 kHz. There has been relatively little talk of what is probably the best frequency for silver 4 kHz. Because so many including Andy seemed to favor the higher frequencies I have mostly used the 8 for hunting and 4 for checking; these report will get me back to utilizing 4 kHz more.

With my Minelab 705 the 4 kHz "Digger" coil although small was the "go to" coil for cleaning a site of silver or any high conductive coins. I found it to have better identification accuracy and as many or more finds than the 6" coil on my CTX.

Too bad that Dues so far has the TX power locked at 3; hopefully they will make this adjustable for 4 kHz in a future software update.

 

[DukeOBass]

Great hunt sniffing out those keepers in 4k! With the Reactivity at 2 and Silencer at 0, you should be able to find deeper stuff at an "uncluttered" site.

 

[Sleepyjim]

Great finds and report CZ!

Did you use the 4Khz prog you post when I asked?

I got a couple hours using that prog from you, in a super hunted out place with tons of trash, yet I got a token and what appears to be a dime???? and a couple other thingys...

Got them cleaning now, will do post after.....

I think the 4Khz is the way to go......

Jim

 

[CZconnoisseur]

Great finds and report CZ!

Did you use the 4Khz prog you post when I asked?

I got a couple hours using that prog from you, in a super hunted out place with tons of trash, yet I got a token and what appears to be a dime???? and a couple other thingys...

Got them cleaning now, will do post after.....

I think the 4Khz is the way to go......

Jim

Jim,

I'm going to run a few more air tests while changing the frequency only and see what pans out. I believe more depth is had with the lower frequencies, but I need to prove it for myself.

 

[Sleepyjim]

Well one of my items from my 4Khz hunt cleaned enough to identify it, it is:

1935 NEW MEXICO 5 MIL SCHOOL EMERGENCY TAX ON 25 CENT PURCHASE TOKEN
Still needs more cleaning time....

The other token is got more to go.......

Jim

 

[samandnoah]

Jim, nice hunt & finds!
CZ, thanks for the update. On finding big iron that sounds good and goes down in 4 kHz relative to 12 kHz (unlike bottle caps), did you notice the difference in readings? I was getting fooled by the same phenomenon BUT have noticed that it typically does not go down by nearly as much as a "typical" target. For example, a zinc penny typically registers 77-80 for me at 12 kHz, and 59-60 at 4 kHz. So I've dug a couple of targets that came in at 78 in 12 kHz and 72 in 4 kHz and haven't found anything worth keeping yet. Still now IH for me, so not quite sure where they register at 4 kHz. Similarly, had some junk show up at 88 in 12 kHz that showed 84 in 4 kHz. So I've noticed that the VDI delta btw 12 kHz and 4 kHz isn't as great when it's been junk. Did you happen to notice whether the difference in going down seemed familiar or within the range you'd expect based on other targets?
Rich

 

[CZconnoisseur]

Jim, nice hunt & finds!
CZ, thanks for the update. On finding big iron that sounds good and goes down in 4 kHz relative to 12 kHz (unlike bottle caps), did you notice the difference in readings? I was getting fooled by the same phenomenon BUT have noticed that it typically does not go down by nearly as much as a "typical" target. For example, a zinc penny typically registers 77-80 for me at 12 kHz, and 59-60 at 4 kHz. So I've dug a couple of targets that came in at 78 in 12 kHz and 72 in 4 kHz and haven't found anything worth keeping yet. Still now IH for me, so not quite sure where they register at 4 kHz. Similarly, had some junk show up at 88 in 12 kHz that showed 84 in 4 kHz. So I've noticed that the VDI delta btw 12 kHz and 4 kHz isn't as great when it's been junk. Did you happen to notice whether the difference in going down seemed familiar or within the range you'd expect based on other targets?
Rich

I've found that some Indian cents will register EXACTLY like zinc cents. Apparently a few early Wheats (the green ones you sometimes find) will also ring up very close or maybe 2-3 points higher in 4 kHz than zincolns. If you are a coinshooter, you can apply a few rough rules for U.S. coins while switching frequencies in the field to determine a "dig" from a "pass". Unfortunately, screw caps LOVE to register almost exactly the same as a zinc cent and Indian cents, and a 8-9" deep screwcap will sound really good most of the time ( at least where I've been hunting!)

So the trend I've noticed for VDI spacing...is the more conductive the target, the less VDI spread there is between frequencies. For comparison I will use 18 kHz VDIs versus 4 kHz VDIs...in order to get a "conductivity coefficient" for some familiar targets. In the real world there are some variations, but to better illustrate the concept I've copied the values straight out of Andy's Book

A 90% silver half reads "96" in 18 kHz and "89" in 4 kHz................89/96 = 0.93
A large cent (100% copper) is "94" in 18 kHz and "80" in 4 kHz.....80/94 = 0.85
A 90% silver quarter reads "94" in 18 kHz and "82" in 4 kHz..........82/94 = 0.87
A 90% silver dime reads "91" in 18 kHz and "75" in 4 kHz..............75/91 = 0.82
A Zinc cent reads "85 in 18 kHz and "58" in 4 kHz..........................58/85 = 0.68
A nickel reads "64" in 18 kHz and "37" in 4 kHz..............................37/64 = 0.58

As a general rule, the more conductive the target, the less VDI spread. Silver targets conduct the best, followed by copper. There is slightly more spread with a large cent vs some 90% silver coins, and this data can be used in the field to determine what kind of metal the target is likely to be. Cast aluminum tends to be a problem especially at depth, since it sounds like coins very often. VDIs will drop if you lower the frequency on an aluminum target, with a tad more VDI spacing vs copper or silver targets. Deep brass or bronze targets will follow the same behavior, with similar VDI changes observed while changing to lower frequencies. Bottlecaps have a coefficient approaching 1.00 or higher - which is a dead giveaway to move on...iron doesn't fit this behavior since it doesn't conduct NEARLY as well as copper or silver.


Try this same test with a crushed soda can - there will still be a VDI spread but the spread won't be like it is on coins. Unless the soda can is 18" deep you probably won't have any trouble passing up a signal like this, not to mention the pinpointing "giveaway"

 

[samandnoah]

Ahh, YES -- screw caps are the on item I've found that has that perfect drop from 12 kHz to 4 kHz (about 20 pts in VDI) that make you say "that's a real target"! But for me, most of them register around 84 (a value btw expected values for good targets), have a very round but echo-y sound, and size up too large for most coins. But I will also say that most of mine have been shallow, probably no more than 3" deep, so haven't experienced what you have. Thanks again for sharing. And I think we're agreeing about the 12 kHz-to-4kHz expected VDIs. The more conductive targets have less of a spread, but the junk targets (other than the screw caps as you mentioned!) show less of a drop in 4 kHz than you would expect knowing some good targets. And I take back what I said about having not found any good targets with that lesser spread -- looking back at my notes I've found some toy cars and a knife that dropped less in going to 4 kHz than I would "expect" for a good target (ie coin). The rest have been junk.

In other words, dig it all

Rich

 

[Sleepyjim]

How about bottles caps going from 4 to 12Khz?


Jim

 

[CZconnoisseur]

How about bottles caps going from 4 to 12Khz?


Jim

Bottlecaps generally with not change much in VDIs across the board, unlike non-ferrous targets. There are different bottlecap compositions which affect the VDI slightly, but ALL of them are steel, and iron + steel alloys are still much worse conductors than zinc<aluminum<gold<copper<silver targets. If there was a way to lump bottlecap VDIs on the LOWER end of the spectrum I would be a very happy camper! I've learned to pick out the caps about 90% of the time, but get one 6" or deeper that's been sitting for a number of years and to me it sounds like a coin mixed in with trash, and I can't help but dig it....