Deep On - Deep Off Test Garden Data

[dgc]

Spent some time in the test garden today. Targets were Jefferson Nickel and Clad Dime both buried at exactly 8 1/2 ".
Soil Conditions - Dense brown clay, moist from recent rains
Detector setup: 8x6 SEF coil, Sensitivity Auto +3 (at 27), Conductive sounds, multi tone, Fast on, Trash high, Ground difficult, Noise channel 5, Open screen

I was comparing readings with only a change of Deep on and Deep off. I swept each target until I got repeatable tones then stopped and glanced at the VID. I did this 4 times for each target.

Data:
Deep On - Nickel readings 35-24, 35-21, 35-37, 1-18
Dime readings 13-44, 1-40, 10-43, 1-43

Deep Off - Nickel readings 9-15, 8-16, 12-15, 17-13
Dime readings 7-44, 1-36, 8-44, 10-44

Conclusion - Deep off provided the most accurate target IDs. Had I been running any iron discrimination, I might have missed the nickel with Deep on.

One other observation. The nickel was freshly buried today. After I dug the hole I placed the nickel at the bottom and swept the open hole. Detector would not hit it. Not a peep. After placing soil back in the hole and compacting it, I started picking up the nickel. I've seen this phenomena before when digging targets. Sometimes after removing dirt over a target, I re-sweep the hole and it seems to be gone. Knowing I heard it initially, I just keep digging until I pick it up with my Sunray pinpointer.

 

[McDean]

Interesting dgc, I usually leave deep off when hunting. Mostly because everything I dig is within surface to 6 inches so I don't feel the need for the deep on setting which allows extra filtering of the target and can slow down response time and throw the #'s (as you have shown) however if at a beach or relic hunting deep on may be the preferred setting with minimal discrimination...

Numbers aside, how did the signal sound with each setting?

 

[Jack Flynn]

Deep is not a filter, it magnify's the sound so you can hear it. In certain instances the report is so faint you cannot hear it. Deep on makes that target sound off for you to hear. It should not affect the TID at all. If you cannot hear it it will not give you a TID. The fast on will affect the TID reading making it less accurate reading wise, turn it to fast off and see what you have.

 

[dgc]

Deep is not a filter...The fast on will affect the TID reading making it less accurate reading wise, turn it to fast off and see what you have.

Jack, I believe Deep on does add filtering.

From the Etrac manual:
In the deep setting there will be a slightly slower reaction in target signal and Target ID due to the extra filtering that is employed in the processing of the target characteristics.

Good idea. I will repeat with Fast on and Fast off

 

[dgc]

Numbers aside, how did the signal sound with each setting?

I couldn't tell much difference in the tone quality or smoothness between Deep on and Deep off. I keep my gain at 15 so I can tell when I'm dealing with a deep target. I've spent a lot of time over deep test garden targets and frankly, I've never been able to hear an advantage with Deep on.

 

[McDean]

Dgc,
You've inspired me to create a "test garden" based on your results... this should be fun!
Before you buried the nickle, did you sweep to make sure there were no other objects (iron) nearby? I only ask because w/deep on, you were consistently getting 35 fe or 1 - which is typical of iron "wraparound"...

Gain @ 15... you are extreme

 

[Goes4ever]

Interesting, please post your results with fast on and off. I have never used deep on.....ever. But I have always used fast on.....

 

[Jason in Enid]

Please try the test again with some level of iron discrimination. Hunting in a fully open screen is a very rare occurance for any hunter, so it should be that the similar settings are used in the test garden.

 

[dgc]

Dgc,
You've inspired me to create a "test garden" based on your results... this should be fun!
Before you buried the nickle, did you sweep to make sure there were no other objects (iron) nearby? I only ask because w/deep on, you were consistently getting 35 fe or 1 - which is typical of iron "wraparound"...

Gain @ 15... you are extreme

Yes I checked for Fe before I buried the nickel. As you can see the Fe numbers were quite different with Deep off.

Will be interesting to see how your results compare to mine. Will you be using the 6x8 SEF coil?

 

[dgc]

Please try the test again with some level of iron discrimination. Hunting in a fully open screen is a very rare occurance for any hunter, so it should be that the similar settings are used in the test garden.

Ok Jason. I'll run it with my slightly modified "relic" pattern loaded. I block out 01- 48,49,50 and 02-48,49,50 to stop iron falsing audio that occurs in the very upper right corner. I leave everything else along the 01 and 02 lines open because I've seen too many deep non-ferrous targets that hit on the 01 and 02 lines. This is one area where I take exception with Andy's book. From my experience, the Fe bounce above 12 on good targets spans the entire range to 01.

 

[McDean]

Dgc,
You've inspired me to create a "test garden" based on your results... this should be fun!
Before you buried the nickle, did you sweep to make sure there were no other objects (iron) nearby? I only ask because w/deep on, you were consistently getting 35 fe or 1 - which is typical of iron "wraparound"...

Gain @ 15... you are extreme

Yes I checked for Fe before I buried the nickel. As you can see the Fe numbers were quite different with Deep off.

Will be interesting to see how your results compare to mine. Will you be using the 6x8 SEF coil?

That"s what had me so curious... the numbers were completely different! High mineralization? Had you been in ferrous tones with deep on it would probably not get dug up.
It"s snowing now and maybe tomorrow too, so I don't know when I will be able to construct a "test garden". When I do though, I'll create a new post with settings used, and other variables along with the results of my observation. I'll be using the pro-coil and ML 8'' coil (smallest I have) I don't think I'll be able to get the sens as high as you with +3 but it should be right up there in the lower to mid 20's..

interested to see your other observations, maybe try manual vs. auto sens at same values?

 

[Rick(ND)]

I know many use them and I did too back many years ago, but these have to be done years ago to be any real advantage as most freshly buried targets are not accurate at any real depth. I had forgot about it until I had a Troy Shadow X5 and did the air test and it did well, buried it about 5 inches and it didn't get it unless I took off the soil on top of it so I called Troy and was told when you do this you introduce air which will throw off your readings and depth. He told me if you pack it down good you will started getting a signal and the more you pack it down the better it will get. I found this to be true as I dug dimes as deep as 10 inches, but as soon as seen the coins i would push the dirt back in the hole and tried it again with no signal and even packing it down still wouldn't at that depth.
Just trying to show you the readings may not be as accurate on your coins if freshly buried, but in actual finds that have been there for years will read different.

 

[sugar]

thank you for all the above information always trying to take it in and understand i too get a problem occasionally when hole has been dug and then it doent sound off and have to pick it up with my propointer it is interesting that you have experienced this i hope you keep testing guys and tell us what your findings are thanks happy hunting

 

[dgc]

I know many use them and I did too back many years ago, but these have to be done years ago to be any real advantage as most freshly buried targets are not accurate at any real depth. I had forgot about it until I had a Troy Shadow X5 and did the air test and it did well, buried it about 5 inches and it didn't get it unless I took off the soil on top of it so I called Troy and was told when you do this you introduce air which will throw off your readings and depth. He told me if you pack it down good you will started getting a signal and the more you pack it down the better it will get. I found this to be true as I dug dimes as deep as 10 inches, but as soon as seen the coins i would push the dirt back in the hole and tried it again with no signal and even packing it down still wouldn't at that depth.
Just trying to show you the readings may not be as accurate on your coins if freshly buried, but in actual finds that have been there for years will read different.

Yes my freshly buried nickel may be introducing an accuracy issue. I packed the soil the best I could but, as you point out, that's not the same as the soil settling naturally over months and years. Thanks for pointing that out Rick.

Still, the two settings, Deep On and Deep Off, are seeing the same test condition so there should be some relevance to the comparison.

 

[dgc]

thank you for all the above information always trying to take it in and understand i too get a problem occasionally when hole has been dug and then it doent sound off and have to pick it up with my propointer it is interesting that you have experienced this i hope you keep testing guys and tell us what your findings are thanks happy hunting

Sometimes I think I enjoy testing a machine as much as I do hunting with one.

Yes the open hole loss of signal phenomena is definitely real. I experienced the same thing with my Fisher detector. I wrote Fisher an email asking about it. Here is the reply from Dave Johnson.

From: David Johnson
Sent: Thursday, May 06, 2010 2:52 PM
To: Daniel Snell
Subject: RE: Technical question - Detector response over an open hole

Motion discriminators are based on the principle of looking for metal discontinuities in a uniform ground matrix. When you create a ground discontinuity by digging, the electronic signal from that discontinuity will either add or subtract from any metal signal present. So,depending on the machine, the ground conditions, and how you are actually using the machine, the ground discontinuity created by partial excavation may make the target signal either stronger or weaker, but most of the time it will make the target signal weaker.

So, the advice to keep digging if at first you heard the signal, is good advice.

--Dave Johnson
Chief Designer, FTP-Fisher

 

[Goes4ever]

When I first made my test garden a couple yrs ago, someone told me to dump 2 or 3 five gallon buckets of water over it to really help pack down the soil. Not sure if it helps or not but before I did that I could not pick up the freshly buried coins I had at 7.5 inches deep. After I dumped the water over them, I could pick them up. And it was not just because of the wet ground because even in the bone dry summer I can hit them loud and clear. I should try your test on my coins to see how it acts, as my teat garden is about two and a half yrs old

 

[dgc]

As promised I repeated the test in my original post with Fast Off and with the Relic disc pattern loaded. Unfortunately due to heavy rains I only had time to test over the nickel (freshly buried).

Results Fast Off / Deep On over the nickel with an open screen. All other settings were the same.
7-14, 1-36, 1-18, 1-28

Results Fast Off / Deep Off over the nickel with an open screen
3-15, 5-16, 1-22, 1-23

I repeated the test with Fast On / Deep Off
3-14, 14,14, 18-14, 27-15

Conclusion: Fast On / Deep Off provided the most accurate results on the nickel

I also loaded the Relic pattern and ran the test with Fast On / Deep Off
4-17, 25-16, 18-14, 16-16

Then the rains came! Goes, I think I'm getting the test garden saturated naturally. Its been torrential rain all afternoon here.

 

[Goes4ever]

just from your results, I feel pretty confident in my chosen settings I have used for a year now, that is fast ON, and deep OFF

it is raining here too, I will do a test over mine garden when I can get a dry time!

 

[Jack Flynn]

What I cannot figure out is compared to my E Trac your fe co's are all over the place. In air tests I get proverbial correct numbers. In the ground I get virtually the same thing not unless there is a little blending of metals going on, ie; confusing the detector.....number wise. My number one rule is, if it sounds good, dig it. My number two rule if it sounds good, dig it. A question, are you making one swing across the coin and recording the numbers? Just one pass.............

 

[dgc]

What I cannot figure out is compared to my E Trac your fe co's are all over the place. In air tests I get proverbial correct numbers. In the ground I get virtually the same thing not unless there is a little blending of metals going on, ie; confusing the detector.....number wise. My number one rule is, if it sounds good, dig it. My number two rule if it sounds good, dig it. A question, are you making one swing across the coin and recording the numbers? Just one pass.............

No Jack, I sweep over the target several times getting a good repeatable signal while intentionally not looking at the VID display. I then stop sweeping and look at the VID and record that number. I repeat this 4 times for each test condition. I have noticed on deep, marginal targets, that my Fe numbers vary quite a bit. When I stated Fast On, Deep Off gave me the most accurate results, I was speaking to CO numbers.