What causes....

[Downdeep]

Went to a new spot on Monday to hunt civil war relics. As I do when I get to any new spot, I dig every positive signal until I get a feel how the detector is working with the ground at this location and how much trash there is. And good I do. My first swing after turning on the V3 and ground balancing gave me a consistant +28 vdi. As sometimes small items come up in this range, I cut a decent sized plug, flipped it and rechecked the hole. This time I got a reading in the high 50's into 60's, right where a bullet should be. Dug more dirt, rechecked and found I had the target out. Pulled out the pinpointer and moved it around in the dirt to find a confederate gardner. The next three targets in the next 10 feet were also gardners. Odd thing is that each of them came up inconsistantly between +4 and +20, with one even bouncing down into -10's.(glad I accepted to -25) BUT once I broke the ground and rechecked the hole, I got a great vdi reading, even some higher than they should have been. I don' know if I'm having a problem with the detector or if its the ground causing this. Each of the bullets was probably in the 8" range. As of yet I can't say I've found anything "deep" with this detector. I even went so far as to lay one of the bullets on the ground to see how far from it I could get. Best I could do while still getting a good reading was about 4-5 inches. Anything higher than that went haywire, giving low positive to negative readings. The detector was running quiet with a gain of 15 and discrim setting of 85. In one area I was even able to run those settings with tx boost on. My bullet on the ground test was with it running wide open like that.

I guess I'm asking..what causes my first experience
and second..shouldn't I be picking up a bullet on top of the ground much better with the detector wide open like that?

 

[Downdeep]

I remember when learning my xlt that Jimmy Sierra had said thatwhen detecting certain ground, too much transmit power could cause a "reflection" so to speak and cause problems. How do I know what ground this is. Will the same happend with the V3?

 

[nw1886]

DD, I took Jimmy's advice on cranking back on the sensitivities and it helps me a lot. (Not in the cleanest of ground but in the average/moderate dirt we find mostly here in the NW.) What does your ground probe say? As far as the anomolies with your VDI's...same thing occasionally happens to me and I couldn't tell you for sure. Could be some kind of disturbing the ground matrix kind of thing? I've had the signal dissapear...put the flap back and...there it is again.???
(This has happened a bit, with all the detectors I have ever owned.) Any one found a more solid reason for this happening occasionally?

 

[thebeatmachine]

My Classic IDX will pick up a penny 12 inches plus easily laying on top of the ground. The V3 sounds like a dud and I don't buy 1600 dollar duds. The DFX is a dud too. My IDX puts out 5 watts of power running to the TX circuit.

 

[BHNugget]

My Classic IDX will pick up a penny 12 inches plus easily laying on top of the ground. The V3 sounds like a dud and I don't buy 1600 dollar duds. The DFX is a dud too. My IDX puts out 5 watts of power running to the TX circuit.

Do you always swing your IDX 12" above the ground?

 

[BHNugget]

DD, are you running the D2?

 

[Neil in West Jersey]

I think in the default filter settings, the D2 requires an EXTREMELY fast swing. I noticed that on broken signals, when I sped up the speed of my swing, the signals cleared up and became more consistent.

 

[Downdeep]

I'm running the D2 coil and have dropped my ground filter to 5khz. I should have mentioned I had tried different filters in the scenarios above and found them to be worse, with my swing speed.

On a opposite note, the penny I have buried in my yard at 10" comes up clean as a whistle with perfect ID with the way I have my program running. Remainder of my settings are relic mode, single freq of 7.5, recovery at 80, accepting to -25vdi, ground filter at 5khz. Running discriminatin mode instead of the factory setting of mixed.

The ground in my yard is way different than the ground in Gettysburg. Even reading posts about it, I haven't done the ground probe yet as I don't understand what it is telling me and what I would do with that info anyway.

 

[BHNugget]

In 3 frq best data,RX 15,TX Boost On,does your machine overload with the D2 in the air?

 

[Downdeep]

Falsing? If I hold it still, no. If I move it, I get falsing.

 

[Taterhead]

Does it false if you tap the side of the coil when you are holding it steady in the air well above the ground and away from EMI? What does ground probe give you when its held in the air?

Does the coil overload if you have it well above the ground and turn the TX boost on when your gain is above 8 or 9?

I have had bad coils which did both of these things, it seems that there are two different kinds of coil failure at the minimum. One is loose housing (Tap from the side results in falsing) the other has to do with the coil being made wrong (overload at high gain or with TX boost and ground probe recommending very low gain, as low as 2 on my partners machine even when it wasn't near the ground, targets, or EMI)

My EMI goes out of whack at 6-8 inches when the soil is mineralized or on salt/iron sand. This seems to make sense, as the signal is traveling through more material that has a chance to effect it. I would guess that this would be common in highly mineralized/salted ground? Or should ground balancing fix this? My machine ground balances almost every 2-3 seconds at the pre-set for C&J, which seems like a lot.

Tater

 

[Downdeep]

When I tested it in the air, I was out away from the buildings, etc. I had the gain at 15(sensitivity probe suggested while in the air), discrim at 85 and tx boost on. I do know the detector receives signals when I tap the coil. It with either give an audible signal with a +vdi or sometimes a nulled signal, but either way I get something from tapping the coil.

Ground probe..if I remember go into ground filter and push zoom? I'll check that in a little while and report back.

 

[Rob (IL)]

I never had the the coil tapping problem, but had badly nulled D2's. Any good coil will not overload in the air with TX boost. if you use the ground probe don't forget to zero. Rob

 

[Downdeep]

Found ground probe...and zeroed.

In the air...
Phase VDI -91
2.5 - +178.
7.5- +178.
22.5- +176
strength at rx gain 15
2.5- .2
7.5- .7
22.5- .8

On the ground...zeroed again

phase VDI -95
2.5- -1.3
7.5- -1.1
22.5- +1.2
strength at rx gain 15
2.5- .7
7.5- .7
22.5- .6

What does this tell me? And how do I use it in the field?
Thank you.

 

[ak_1234]

When you looked at your ground reading, did you zero with the loop in the air? You need to zero with the loop in the air before lowering the loop to the ground.

 

[Downdeep]

hmm. not sure. I know I zeroed in the air to get my air reading...dont know about ground. I'm thinking I may have done it while it was on the ground. Never played with it before, will do it again tomorrow when I am home. I'm guessing I misunderstood the directions...