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Took a two day jaunt this week. About 60% prospecting and 30% detecting. Still looking for that virgin spot. A lot of rough country, very steep, rock covered hills, washs and canyons.

Went in as far as the quad would take me and hoofed it from there on in.

Was looking for a certain area over by.......well thats another story. Anyway had been checking my GPS on occasion, so stopped for another check and found that I had over shot the place I wanted to stop, by a good half mile, so had to back track a ways.

After I got my pick, a couple canteens of water, GPS, and 3500 with a 14" round mono, I hit the hill from the bottom of the canyon. After about twenty minutes of climbing and trying to detect at the same time, I think I know just how a billy goat feels, and by the time I got back out of there, I also know how he smells.

Somewhere not so far from the top, the terrain leveled just a bit. A good place for a short break and drink of water. Shut the detector off, had a drink, and checked my location again with the GPS. Looked like I still had about two tents of a mile to go.

The area looked good to me. Lots of Quartz, loads of decomposing granite and a touch of exposed vertical or near vertical schist here and there. Did see a few old diggings here and there and also found and old miners pick at the base of the hill, [no handle] wedged between a couple of rocks.

My GPS has the ability to switch to or pull any one of seven different screens, at any time. My thought was to pull up the Plotter Screen. This would give me a continuous visual track of where I had been. Much like drawing a circle, square or zig-zag line on paper. I wanted this in memory so I could later transfer it to a 7.5 quad. so it would show me exactly where I had been.

So I set up the GPS, picked up the detector turned it on and let it tune up, and ground balanced it.

At that point all hell broke loose. The detector sounded like it was in great pain and was about to die. I have heard it make a lot of different sounds in my time but not like this. It was warbling, screeching, and screaming and doing everything but playing taps, not to sure it wasnt doing that also.

Put my test piece on the ground and you could hear the signal but you had to listen real close to pick it out from the rest of the noise.

At that point I shut it down, thinking, well this is a hell of a place for the 3500 to throw craps. I checked the coil cord and everything seemed to be OK, nothing broken winding snug. Checked all fittings, nothing loose, everything as should be. Pressed on the fittings, wiggled them, nothing loose. Had to be that 14" Coiltek coil. Fired it up again, let it tune up, checked all fittings again, shook and bumped the coil, the same as if I was detecting. No change in all the noise.

Its too bad someone was not with me, because they could have bought a cheap machine, at the time. Besides it was hotter than hades and the blood preasure was rising by the minute. At that point I was looking for a scapegoat so it seemed that Rob and ML should be at the top of the list.

I shut down again, just had to be that Coiltek Coil, checked it over again, nothing broken, no cracks, dents or anything. As I sat there looking at it, the thought popped into my head, I wonder how far this whole thing would fly down the mountain side, if I was to give a whirl and release it, kind of like a discus thrower.

I fired the rig up again, same old problem. At that point and having checked everything several times, I thought, naw couldnt be, but then I havent checked that. So out comes the GPS, yep, still working great, turn the thing off. Yes the 3500 was now purring like a kitten.

Sorry Rob and ML. Nothing wrong with the Coiltek [great coil] or the ML.

I don't know about all the others out there, but my GP 3500 is certainly no fan of the GPS systems.

So if your running a GPS and the detector goes crazy, shut the GPS down and see what happens.

Bob T.

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Bob, have had the same problem. Have GPS mounted on Quad, which is left on all day to track my where abouts. Gotta get 10' away before turning GP3K on, no matter what coil. Wish I could wear GPS at times, but don't even try. At Gold Basin, even noticed cell phone worn on belt and on caused problems????

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Colo. Bob and Shep,

I have noticed both problems too. I like to wear a gps for the same reason

you do Bob, to track where I've been and where I'm going.

There are times when the 3500 simply won't accept the gps signal at all and I have to

turn it off...but it's not a constant, sometimes it's fine.

The cell phone is also a huge contributer to having the 3500 act up. I usually am out range

on my stupid Verizon phone anyway, so it does't matter that much, but it can be

a big problem if it's on when you're trying to detect.

regards,

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Colo. Bob and Shep,

I have noticed both problems too. I like to wear a gps for the same reason

you do Bob, to track where I've been and where I'm going.

There are times when the 3500 simply won't accept the gps signal at all and I have to

turn it off...but it's not a constant, sometimes it's fine.

The cell phone is also a huge contributer to having the 3500 act up. I usually am out range

on my stupid Verizon phone anyway, so it does't matter that much, but it can be

a big problem if it's on when you're trying to detect.

regards,

I'm having trouble understanding this issue. Not trying to start anything just need to understand how a passive instrument like a GPS can cause signal interference with a detector. A cell phone makes sense as its a high freq transmitter but a GPS is only a receiver without any transmitting RF so how does this happen? If anything I would think the detector would mess up the GPS accuracy. :blink:

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Even if the electronic device is only a receiver it is not passive because it has an oscillator circuit that still emits a very weak signal and if it is in close proximity to say your GP3500 it can still interfere with the detector. I hope this is helpful Bob. God Bless and be careful out there.

John Tomlinson, CET

John's Detectors

Best in the West ! ;)

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Even if the electronic device is only a receiver it is not passive because it has an oscillator circuit that still emits a very weak signal and if it is in close proximity to say your GP3500 it can still interfere with the detector.  I hope this is helpful Bob. God Bless and be careful out there.

John Tomlinson, CET

John's Detectors

Best in the West ! ;)

Wow, for sale... one new "highly blinged" 2100 sd v2 that can't see gps reciever interference from one foot away. Would hapily trade for a 3500 :blink:

Mostly just kidding so don't get the panty's in a wad but all those years at tech school have gone to waste I guess. Is a 3500 THAT much more sensitive? If it can see the timing pulse from a sheilded gps I am truly impressed and need to change beepers I think. I also think there must be a better explaination to the interference than a gps being near. What other reasons have been considered?

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Lotsa Luck,

and my panties are doing just fine...

LOL...

Now that's different but does it transmit your position automaticaly or does the problem only occur when you are talking with your second? Even so I would think the bleed over should not be so bad as to cause a problem but maybe Motorola has cheapened up a bit in recent years and the FCC just lets it go. :o

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Colorado Bob,

Glad your situation ended well and no Minelab gear was chucked off the mountain. You can be glad you didn't drive 200 miles and then unwittingly forget to screw in one end of the power cord and *poof*$#@! Have the detector cease functioning on the spot. Looks like a shipment to Minelab is in order for me :mellow::o:unsure:

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Thanks for the different views on the subject matter.

Naw, I wasnt going to chuck it off the mountain, just talking through my hat, [ however the idea did cross my mind.] :o

Have never had a problem with the 3500 or the Coiltek coil. Have used that 14" Coiltek a lot and really like it. I swing it all day without the bungie as I dont like the harness in this hot weather. Was around 110 today!!!

I'm thinking that maybe the age of my GPS has something to do with the interference. Maybe its not shielded as well as the new ones. Mine is probably 8 yrs. old.

Not being an electronics guru, I have no idea why it happens. I do know that the results are the same if I'm here in Quartzsite or a hundred miles away over in the Wickenburg area.

Guess its about time to up-grade to a new Garmin. :)

Bob T.

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Hey Bob,

If you do decide to upgrade, I would suggest a Garmin Rino as one option.

It has a GMRS radio and a weather band built in. It also is great when you're hunting

with another person who has one; when you key your radio you transmit your position

to the other person's gps screen. Cool.

http://www.garmin.com/products/rino530/

(this is the most expensive model, there are three other, less expensive Rino's)

regards,

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Wow, for sale...  one new "highly blinged" 2100 sd v2 that can't see gps reciever interference from one foot away.  Would hapily trade for a 3500 :blink: 

Mostly just kidding so don't get the panty's in a wad but all those years at tech school have gone to waste I guess.  Is a 3500 THAT much more sensitive?  If it can see the timing pulse from a sheilded gps I am truly impressed and need to change beepers I think.  I also think there must be a better explaination to the interference than a gps being near.  What other reasons have been considered?

Sorry fella I don't wear panties.

John Tomlinson, CET

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HA !

Back in the days when the SD2200 was the Ducks Nuts, I got this brilliant idea to help fight the boredom of swinging for hours with no targets in virgin ground. I'd listen to some music.

I had this little am/fm portable radio that runs on one AA battery, no speaker, just ear buds. I'm thinking, I can use one ear bud in one of my ears, and headphones over it, and I will have a lovely way to detect and hum along with the tunes.

So I place the earbud in my left ear, tune it to the appropriate FM channel, ah yes, delightful music it was, "sittin' on the dock of the bay, hopin' some nuggets come my way, just sittin' on the dock of the bay la la la, la la la."

OK, put the headphones on over the earbud, yes no problem at all, very comfortable.

I proceed to turn the SD2200 on and the most God awful screach comes out of that ear bud, something akin to having a knitting needle shoved through your ear and into your brain.

I scream and rip the headphones off to get rid of the excruciating assault on my eardrum. But it doesn't stop, I mean this was really painful. So painful that it had not occured to me that the sound was not coming from the headphones, but from that single earbud that was now making me bleed from the nose. Finally, I realized that it was the earbud, and the radio picking up the interference from the SD that was the culprit, and I yanked it from my ear.

I would have liked to have seen a video of myself, I probably looked as if there was a bee in my headphones as I dislodged them and threw them to the ground all the while jumping around and screaming.

Those PI machines and other electronics just don't seem to mix well.

BCOT!

DOC

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I had a stupid watch that would sing a little tune every hour on the hour. Believe it or not , my PI would go nuts every hour on the hour for a few seconds. Don't wear that watch detecting any more. It's no wonder that a lightning storm causes problems.---Bob

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