coil depth

[Cache Man]

what is the depth difference between a tornado 10" coil and the sun-ray s-8 coil? is it 2"-3"
Thanks.

 

[grumpy]

I would think more like 1 or 2 at the most difference. Check it on your machine (found machines and coils will varry from one to the next) with a quarter held flat and a wooden or plastic ruler (air test) After that you have an idea but all the other factors that come into play when you actually hunt pretty much makes it a toss up. diff moisture content that day wheather you have on the 8 or 10 , minerals in the soil , coins or rings laying flat or on edge. Personally I think coil size is mostly a trash and seperation issue thing not a depth thing so much.
Just my 2 cs worth; which ant worth much.
Grumpy

 

[jbow]

Hard to say. You may be able to turn the sensitivity up more with the 8" coil and get more comparitive depth. I don't know though... but you never know.

I do know that I can get almost the same depth with a 5.75 HOT coil on a Tejon as I can with the stock 10" spider coil. I can get 10" on a quarter with a 4.75 coil on a T2...

J

 

[Minermangold]

Everybody by now should know minelabs DO NOT airtest well , simply lay out a test garden with a quarter at 8" and a penny at 5" . You can also mark those buried items with small colored flag or other kind of marker. Only then can you do "proper" comparisons , I have personally found sunray coils to perform slightly better due to more stable operation. And one important rule to remember in your testing is to experiment with coils only when minelab is at OPTIMAL operating power ( fresh battery or full charge).

My sovereign will detect targets deeper in ground than air because the machine needs to "read" the surrounding soil conditions to perform not open air.
There is no one coil that will do it all , I use sunray s5 for parks, heavy trash , original 10" for beach ,general hunting, and finally a WOT 15 " for extreme wet and dry sand hunting.

 

[Goldringer]

Depth is always an interesting subject and often overstated. Few people really know how deep they are going. i used to provide all sorts of depths until I decided to do some controlled tests. By controlled I mean that i took lengths of plastic tubing, measured them precisely and placed a known value target in the bottom of the tube. My chosen target was a mans size 10, 4mm wide, comfort band by FG. This is a rather heavy piece of 14K and not an uncommon real life target. i then inserted the tube into the bottom to a depth where the top of the tube was flush with the bottom. Next I took a total of 5 different detectors, all that i owned at the time and tuned them to the location. I recorded the exact depth each would get a barely discernible response from the target. I varied the depth by inserting a measured plastic spacer under the ring in the measured tube. i made sure that my coil was passing and touching the top of the tube. the tube was of course vertical into the bottom and back filled with sand and salt water when submerged.

I was very surprised at how I had over estimated actual depth. Not one of my detectors would detect that ring at more than 9.750 inches in clean lightly mineralized sand in salt water. I learned that larger coil size did not equal deeper depth. I learned that in most cases an 8 inch coil proved deeper than a 10 inch coil. I have repeated the test several times now with same results.

I believe that the concentration of power by an 8 inch coil seems to optimize performance. I have found that while an 8 inch and 10 inch might have the same depth each has an advantage depending on conditions. an 8 inch will out perform the 10 in trashy or highly mineralized areas. the 10 will cover more ground faster in areas with minimum trash / targets. The 8 inch coil can perform well with a faster sweep. The 10 inch is easier to cover every inch hunting zone. Coils less than 8 inches seem to lose depth capability as well as coverage but can pick a good target out of heavy trash.

I have now completed these tests in salt water as well as dampened mineralized soil with similar results. I did not have any large Wot coils for this testing, only stock coils as provided by detector manufactures.

In real world hunting an old target can possibly be detected at greater depth as a result of the "halo effect" of electrolysis.

 

[Serge]

Good observation Goldringer,

I do my test Little bit the same way . I use a small nylon bag attache to a line. I have 6 marks on that line 4" to 10". Dig the bag 12" deep and pull the line until i get the signal. That's a test kit that i always carry with me. I use it to maximise my setting . Also where i hunt, there is almost no mineral's soil, so i use very high sensitivity to get the signal deep, but the return signal is not as precise. Those test help me to understand the deference between the deep signal and the regular one. In my particular soil, the 10" was just a bit deeper. My test was maid with the same detector (excal11) but on different times, witch can change the result to.


Did you try the 8" and the 10" with the same detector?

Witch machine did you test and witch one had the best response?

Thank you for sharing those test with us.

Serge

 

[Cache Man]

This is great info,I thought I needed to get a 10" tornado ,I got my elite without the stock 10" coil the 8" S8 sun ray is doing a pretty good job but I need Moore depth the coins at this 1840's site are pretty deep, I have found 1940/s silver back in the early 80's 8"-10"deep that's why I got a sovereign so I can get to the old silver,I thought I had one this week, weak signal pin point did not change at 18"deep was a aluminum can. I find clad coins at this site 6-8" deep, I am the only person to detect this site, I didn't realize the sink rate was that bad until I found the can, its not been back filled I have lived next to this property since the 1950's were I grew up. is it normal to find rusty nails in each hole? the aluminum can hole had 2 nails in it, every time I find money theirs always 1 or 2 nails in every hole, this wk I found some ones plastic Easter egg with several 1980's quarter's inside at 8" deep and in the same hole was 2 rusty nails and one aluminum nail. I have hunted this same place with a new fisher f70 with 11" DD coil but it didn't find what I have been finding with the elite.the silver at this site may be unreachable, but I keep trying, this a great forum I have been lurking (reading) all the post and alot of the old post going back 2005. since early spring, thanks for help.
Cache Man.

 

[Neil]

Depth is always an interesting subject and often overstated. Few people really know how deep they are going. i used to provide all sorts of depths until I decided to do some controlled tests. By controlled I mean that i took lengths of plastic tubing, measured them precisely and placed a known value target in the bottom of the tube. My chosen target was a mans size 10, 4mm wide, comfort band by FG. This is a rather heavy piece of 14K and not an uncommon real life target. i then inserted the tube into the bottom to a depth where the top of the tube was flush with the bottom. Next I took a total of 5 different detectors, all that i owned at the time and tuned them to the location. I recorded the exact depth each would get a barely discernible response from the target. I varied the depth by inserting a measured plastic spacer under the ring in the measured tube. i made sure that my coil was passing and touching the top of the tube. the tube was of course vertical into the bottom and back filled with sand and salt water when submerged.

I was very surprised at how I had over estimated actual depth. Not one of my detectors would detect that ring at more than 9.750 inches in clean lightly mineralized sand in salt water. I learned that larger coil size did not equal deeper depth. I learned that in most cases an 8 inch coil proved deeper than a 10 inch coil. I have repeated the test several times now with same results.

I believe that the concentration of power by an 8 inch coil seems to optimize performance. I have found that while an 8 inch and 10 inch might have the same depth each has an advantage depending on conditions. an 8 inch will out perform the 10 in trashy or highly mineralized areas. the 10 will cover more ground faster in areas with minimum trash / targets. The 8 inch coil can perform well with a faster sweep. The 10 inch is easier to cover every inch hunting zone. Coils less than 8 inches seem to lose depth capability as well as coverage but can pick a good target out of heavy trash.

I have now completed these tests in salt water as well as dampened mineralized soil with similar results. I did not have any large Wot coils for this testing, only stock coils as provided by detector manufactures.

In real world hunting an old target can possibly be detected at greater depth as a result of the "halo effect" of electrolysis.

If youve hunted the beaches enough with various coils you should know what gets you the best depth, the best sensitivity and so forth. take a small tape measure with you if your not good at judging distances and also you can use your scoop handle as measuring device also.
as far as the 8" coil getting greater depth, not here is all I can say. depth wise here is a descending order of what I found from deepest to least.

WOT
S12/10" Tornado
8"Tornado/S8/8"coinsearch/joey coil
S5
same line=same approx depth
soil conditions can vary day to day as well as tuning the detector correctly

one home test I did find very useful and hard to do in the field was to bury a ring and coin next to iron and see what coils picked up the ring/coin and from what directions. widescans are clearly better is what Ive found.

on the minelabs not air testing well, they do better in the ground but do air test well actually, just make sure and do it outside and not inside with the tv on or other appliances. and the new etrac, air tests very very well

this is just what I found hunting ocean beaches in NJ. I would guess different areas might provide different results as do operator skills provide different results.

Neil

 

[kered]

The deepest i used on the sov at the beach was the 15x12 SEF, very stable and very sensative to smaller targets too

 

[crazyman]

I use the 10 inch slimline and the S-8 on my Elite and in my ground which is pretty hot there is not much if any difference in depth. I can run my sensitivity much higher with the S-8 while with the 10 inch I usually have to run in auto sens. to keep a steady threshold without ground null. In some areas with better ground I can run the sensitivity at about 3 o'clock with the 10 inch. On the beach the 10 inch has an edge though.

 

[Ron from Michigan]

For most parks in my area the 10 inch Slim Line gives excellent depth.Even with the sensitivity turned down a little it still has better depth than the 8 inch Coinsearch or 800 Tornado coil.HH Ron