Question for Rick on the GT.........

[Art (NWOH)]

Don't know if this is normal, but is a bit of an irritation.........

My GT responds with the correct tone and meter reading as long as the target has a HIGHER conductivity than the previous target. That's OK.

The meter and tone response is WRONG if the next target is LOWER than the previous one.

Example.........

Swinging the coil over a nickel, then a zinc, then a dime, the zinc and the dime will read right and produce the correct tone. BUT if I swing back to the zinc after the dime, the tone and reading are too high. Something on the order of a high screwcap or silver ring.

No amount of wiggling the coil will drop the reading to normal. Only way to get back to normal is to deliberately false the detector by giving a fast vertical pop to force a iron response, or by swinging the coil over my boot.

I don't consider this to be all that big of a problem, but will require some consideration at particular locations.

I was used to my 2a requiring a couple passes to come up with the right reading, but it was never so determined to hang in one place.

Does this seem right to you, or is there something a bit different about the GT ??

HH

 

[Rick(ND)]

I really never notice this and will have to check this out on the dime, then the zinc penny. The tone is close, but with my SunRay DTI meter with the 180 numbers is where I can see the difference. I will have to check this out on Tuesday if I get a chance in the field.
One thing I have notice with the GT and the SunRay meter is I have not yet not got a 180 on a good coin, my XS and XS2 plus the Elite on the faint ones sometime I couldnt get a 180 on the meter, but knew the tones were climbing along with the meter readings so it was one I would dig.
I did get a IH on Saturday I was able to get a 179-180 out of instead of the 176-177 normally with a new coil I am field testing. The IH was a good 8-9 inches deep and was very hard to get a signal in pinpoint, yet in disc I could get a 179-180 doing the Sovereign wiggle :?:
I feel the GT may be able to lock on better to some of those deep ones I am seeing. I also notice some of the iron is fooling me more too, but I feel I am learning a new way to tell the difference now.
I will try to do this test on Tuesday and post the results later in the day.

Rick

 

[Art (NWOH)]

In response to your post first.........

The GT does seem to ID better on weaker targets than my 2a.

Now, on to my "problem".....

Took 3 cups of coffee in my living room to do this.

The thing about not turning up the right ID.....

Some times could get the ID after just a couple passes, sometimes took more than 10 passes. The more furiously I waved the zink, the longer it took.

Got closer to the coil tip and noticed that it worked better.

Increased the distance over the center of the coil, and it worked perfectly.

So it seems that if a descending order hit is very strong, this is going to happen with my GT.

Will have to keep this pattern in mind.......must raise coil a bit to get good readings on strong hits that are in descending order.

Have also noticed that raising the coil will some times "break loose" the iron and hot rocks.

Does not appear to be a defect.....simply an unexpected oddity.

HH

 

[Art (NWOH)]

This spring right after getting the GT.........

Went out two days in a row to the same iron infested site. First day with the T-10, next day the S-12.
S-12 did not seem to grab for the iron the same way the T-10 did. Ground was perfect, uniform moisture.

Coil selection may make a big difference on how the GT grabs the unwanted stuff.

Now, this strong hit (shallow or surface) thing is very similar to my QXT. It also really hates them, and has ID problems until they get down a ways.

Just other things to think about.

HH

Art

 

[Rick(ND)]

I got a chance to try it today at one of my sites and was using a 8 inch coil. I put the dime and the new zinc penny on the ground about 5 inches apart. I would swing over the zinc penny first and get my 176-177 reading then went over the dime and it went right to 180. Now I got a good lock on the dime and would swing back to the zinc penny and it would sound about the same, but my SunRay DTI 3 dropped right to 177 the first time over it then 176 when it seen it on the return swing. I even got it when I almost touched the coins. Now this is with the 8 inch coil and the SunRay DTI 3 meter as I didnt get a chance to try the stock 10 inch coil and it may do it. With the number so close it is hard to hear the difference and why i like a good meter like the DTI 3 as a number or 2 can make a difference where the tones is so close it is hard to tell.

I wonder if other have tried this and see what they come up with as I too am curious.

Rick

 

[Art (NWOH)]

Had the coins about a foot apart and was moving fairly quick. Running 547-548 at first when going back to zinc. Went down to 545 or so with more passes. Expected 539.

Seems very strong hits don't want to go down to correct value.

Makes readings very stable but can be erroneous.

Tone is hanging with the reading on the meter.

Couple times had meter and tone stay at 550 clad on the zinc.

Don't seem to like very strong hits.

Thanks for comparing. Appears to be normal to the GT.

Anyone else welcome to share on the subject.

Thanx Rick.

HH
Art

 

[Art (NWOH)]

Looks like it dropped right in after a couple passes. I'm running over 3 times the target resolution you are.

Don't know what kind of coil you are running. May have something to do with it.

Have same trouble with the Detech coil. Maybe more so than the T-10.

Should try the S-12, as it seems tamer around iron.

Fun and games.

HH

 

[berkeley bottle boy]

You don't have auto-ground-balance on or something like that do you Art?

What happens if you go from a dime to a nickel? Does it go from 550 to 470 (sb 445)?

Does it do the same thing with an S-1 probe that it does with the coil?

 

[Art (NWOH)]

Didn't pay any attention to the nickel other than at first when it read 420. Picked it up and got a null on the spot. Either a piece of iron or a hot rock.

Don't have a S-1. I use the pocket Uniprobe. No additional weight to the detector and can use with anything.

The tracking switch has no effect in disc mode, so this was not an issue.

Iron mask on/off, no effect. Band 1/2, no effect.

Just don't want to back down the reading and tone on a very strong hit.

Usually this will not be a problem, as there will usually be enough trash around to keep the tone and meter below most of the good stuff.

Besides, a lot of the time, I just walk over zincs anyway.

If it's loud and distorted I don't want it in most places.

HH

 

[Rick(ND)]

I put the stock coil back on and put a nickle, zinc penny and a new dime on the ground and went over them one at a time, everything sounded like it should and locked on. I went over the dime first and it went to 180, then went over the zinc penny right away and it sounded the same, but my Sun Ray meter read 177 like it should have. Went from the zinc penny to the nickle and the first pass it read 148 instead of 145, but on the way back it dropped to 145. I event tried going right from the dime to the nickle and it worked just fine. When I dragged the coil on the dime, then the zinc penny it too read like it should, but more erratic reading being it was touching the coins.
Are you doing these test in the air or on the ground as mine have been all on the ground.
I left the coil on and went back to my farm yard to see if i could find anything I may have left with the other coil I was testing and got nothing where I was before. I tried a few other areas where I hadn't been before and got a 1941 nickle , a 1908 IH and 6 Wheaties, a 1957, a 1929, a 1927 S, 1925, 1912 S and a 1910 with the IH, the 1910, the 1912S, the 1925 and the 1927 S in the same hole as they were on top of each other. The 1925 even has the new coin luster in spots as it was between the other coins. It gave a reading of 176-177 on my Sun Ray meter even though it was 8 inches deep.
For a farm yard that has been worked hard 3 years ago by 2 guys with other detectors the Sovereign and the Explorer has done well for me with over 40 old coins between 7-10 inches deep in around 15 hours. I also got 2 old toy cars, a nice kids ring and a real old lighter, maybe one of the first ones made as it has 2 caps on it , one for the fluid and the other one for the wick that are pulled off.The spark wheel on the outside of the lighter and see no name on it. it is about 2 1/2 inches long and little bigger than a dime around.

 

[Art (NWOH)]

Sounds like you been having fun.

I was testing both on the ground and air tests with a distance of 2-4" .

Could hear the tone hanging and stepping down when the meter hung or stepped down.

Must be a peculiarity of my machine. Most of the time it won't be worth worrying about.

HH
Art