Ground balancing question


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I've got another rookie question. Can area thunderstorm conditions affect the ground balancing of the Minelab 5000? Couple of days ago we here in central Arizona had quite a bit of bad weather, thunderstorms, tornadoes, rain. I was having some difficulty getting a smooth threshold. The bad weather was not in the immediate area, but was close enough that I didn't venture too far from the truck. Makes sense that it would have some effect, but would asppreciate some advice. Thanks.

Lyle

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Lyle,

Yes EMI's from Thunderstorm will mess with your ground balancing. Now, I don't swing a GPX 5000, but I have some buddies that do. During a few of our hunts when the storm clouds started to pop up on top of the Sierra's we all heard the EMI's. You keep at it and fill your poke.

LuckyLundy

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It can also affect your conductivity, a Metal Detector makes a great lightening rod. Be Careful.

We have always had good and bad interference days in Gold Basin. We thought it was microwave towers.

We finally discovered that the problem was caused by whenever they had the generators running at Boulder dam. The EMI obviously goes right into the water and into the water table.

The water is so low at Lake Mead they don't run the turbines very often anymore.

Doc

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Dave it's not a great distance. Lake Mead, which was created when the Colorado River was dammed up, is only 10 miles from the place we detect, and there is actually placer right up to the waters edge. (Although he are not allowed with detectors onto Lake Mead Recreational Area.) But I have been down there on the Arizona side and there are old workings and hand stackings everywhere.

Every gully and wash we detect drains directly into Lake Mead.

Those turbines put out an enormous amount of power, enough that it supplies some to Nevada, some to Arizona, and most of it goes to California.

Here's a picture of Boulder Dam and the new bridge, although the bridge was photoshopped into this shot. It looks just like this. I think they didn't want anyone to see the lake in it's current state, we have had an 11 year drought and the lake is very low.

Seagull_View_Rendering_10_02300dpi[1].jpg

Take care!

Doc

DOC,

That is so interesting! Had no idea that something like running generators from that

relatively great distance could actually effect the water table and ground conductivity.

Amazing.

I love learning about stuff like this.

Flak

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Dave it's not a great distance. Lake Mead, which was created when the Colorado River was dammed up, is only 10 miles from the place we detect, and there is actually placer right up to the waters edge. (Although he are not allowed with detectors onto Lake Mead Recreational Area.) But I have been down there on the Arizona side and there are old workings and hand stackings everywhere.

Every gully and wash we detect drains directly into Lake Mead.

Those turbines put out an enormous amount of power, enough that it supplies some to Nevada, some to Arizona, and most of it goes to California.

http://www.hooverdambypass.org/HooverDam1.wmv

The lake has 357 miles of shoreline, if I remember correctly, and it is 57 miles from one end to the other, not counting where the Colorado river enters the lake. If you go up the Colorado river you end up in the bottom of the Grand Canyon.

Take care!

Doc

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If the detector is being use in Fixed then EMI will not effect the Ground Balance, if detecting in tracking mode the loud pings and warbles could pause the GB as if a large target has passed under the coil but should not overly impact on outright performance. If doing an auto tune and a loud ping hits (usually lightening strike) then that area of the tune position will be put aside as being noisy by the auto tune software.

If the detectors threshold is unstable with the coil held flat you should be able to tune it out assuming your not too close to the source of interference, if the coil is tilted then Sferics can be allowed in which can be tuned out to some extent but usually it is best to keep the coil as level as possible. I would not recommend detecting with thunderstorms about.

If the detector cannot be tuned to deal with the interference then use the supplied DD coil in Cancel mode, if the mineralisation is high then use the detector in Fixed GB in the Fine Gold or Enhance timings.

Hope this helps,

JP

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Thanks for all of the advice. The possibility of interference from the nearby storms made sense, but, not being all that familiar with detectoring, I was wondering if I had something goofed up with the settings. I had only the mono coil with me, was running fine gold in fixed, and did pack up and go as the storm was approaching over the horizon, mainly because of what Doc mentioned about the conductivity of the detector. We are new to the area, and plan to get up to the boulder dam in the near future. Must be quite a sight in person. Thanks again for the help.

Lyle

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HI Lyle,

I was in Gold Basin Arizona 1 week ago when the big thunderstorms came through. The 5000 actually was pretty quiet, except for the lightning, in which came the loud zip. I was mainly using a 12x15 commander mono coil. I also found that manual tuning and turning your RX gain down a little in the stormy weather almost blanks any interference to zero except lighting. I have also noticed coiltek coils are a lot more susceptable to the interference than the commander coils in stormy weather.

Dave

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I once had a garret ads blow some part from an atmospheric electrical charge...I was at least 30 miles from the thunder and lightning too. Most people don't realize that lightning and electrical charges can occur many, many miles from the apparent source of the storm...I don't go detecting during thunder storms anymore...

fred

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