Beginners Guide 101: Calibrating the Sov GT Meter

[Anonymous]

Okay... I'm stumped.

I received my new DigiSearch meter for the Sovereign GT today. Excitement turned to disappointment rather quickly. :cry While I never expected to rely solely on the meter for discrimination... I had hoped it would aid in the process. I'm sure it does because there are a lot of satisfied Elite owners out there (as well as the GT owners with meters.) I just got gotta figure out what I'm doing wrong.

I grabbed the Sov GT manual and turned to the section "Calibration of Meter"

First... it says calibrate to 170. NOTE: A thread in this forum stated that Minelab identified the manual was wrong and it should have stated 180. Even though 180 is now the norm with the recent recalibration efforts, has anyone else confirmed with Minelab that the manual is wrong at 170?

Heck 170 or 180 doesn't really make a difference at this point... I'd be happy with either one!

I've tried using a new quarter (and other common coins) passing them past the coil. As far as adjusting the display to 180, its impossible. As I pass the coin under the coil the meter fluctuates wildly from 45 to 260 and every number in between. I can make multiple passes at the very same slow speed and never see the same sequence of numbers twice let alone where it shows a tendency to display a fixed number like 170 or 180 or even a fraction of a second

I've tried adjusting the meter in the smallest of increments (a breath at a time) but the meter reading still jumps all over the place, no rhyme or reason.

In desperation I decided to create a test where I could control some of the variables. I glued a three quarters to a eight foot length of plywood. A jig was used to hold the plywood in a path that would remain parallel to the center of the coil as the quarters moved underneath. All three quarters were 2001 (Maryland version) I then clamped the Sovereign so its coil was one inch above the surface of the plywood. As I move the plywood (quarters) under the coil, the tones sound identical as each one passes in and out of range...but... the meter never reflects the same numbers twice. Just wild swings up and down thru the spectrum no matter how slow I do the test. Never comes close to settling in on a specific number... not even for a second. At this time I see no way the meter offers any value add in discrimination.

Obviously... (hopefully) I'm doing something wrong. Sure don't want to think I got a bum meter. Can anybody out there set me straight? Suggestions for initial GT control box settings prior to the meter calibration? Anybody here have a write up; i.e., "Calibrating your Sov Meter 101"? :sad
Elton

 

[Art (NWOH)]

Sounds like you are in all metal mode. Meter only works for ID in discriminate mode.
HH

 

[Mike Bearden]

I didn't read in your post whether or not you conducted the meter test while in all metal or disc mode but here's what I found with mine.
The adjustment knob was so radical or touchy might be a better word that once I finally got it to read 180 on a silver coin ... all I had to do was barely breath on it and it was off the mark again. :rage I was having to reset the meter everytime I took the detector out of my truck,
As bad as I hated to do it, I opened the meter housing up and removed the knob pot assembly from the board and replaced it with a detent style pot. I recalibrated it to read 180 on silver again at the mid way point on the knob.
Not recommended for everyone because of warranty issues !!!
Now the meter is dead on and stays dead on, and if by chance the knob ever does get moved .. all I have to do is click it around back to it's centered mark and it's dead on 180 again.

Just for good measure I removed the 2 rivets from the meter mount, drilled and tapped the shaft to fit a threaded stainless steel machine screw & nut combo. This allowed me to mount the meter bracket low in the back and high in the front so it's now allot easier to see.
Now BOTH the meter and bracket work like a charm :cheers H.H.
Mike

 

[Anonymous]

Okay...so this is the best smiley I could find to display my embarrassment :blush

Although not intentional this SNAFU would serve as a good example of why some of us would like to see a Sovereign book. In fact, you just identified one of the tidbits that should be covered in the book! Thanks

In my own defense I made the mistake of reading the instructions (i.e. Users Manual... My wife always complains I never read the instructions)
After installing the meter, I turned to the "Calibration of Meter" section in my Sovereign GT Users Manual. I carefully followed "all" the steps. Nowhere in the calibration section does it say to the detector cannot be in all metal mode, or to take it out of all metal mode, or that it won't work in all metal mode, or that it will only work in Disc mode. :ranting

Exacerbating the problem... I was previously reading thru the "Quick Operating Instructions" section of the manual. In this section, the last Quick" setting they have you setup is the all metal mode. Since I was finding more stuff (including trash) in this mode I didn't think to change it. DOH! :sad

Like I alluded to in my post seeking a "Mastering the Minelab Sovereign" book... One dial, one switch, set in the wrong position and you could pass over the treasure of a lifetime.

 

[Anonymous]

Mike... I was conducting my test in all metal mode. DOH!

For some reason I wasn't initially able to open your reply on the first two or three attempts... Strange. I was able to open Arts reply first attempt ... he made me see the error of my ways.

After a couple more attempts I was able to open your reply. Anyway... my meter behaves the same way as yours did. I swear even breathing on it can cause the setting to change.

Although I have no trouble modifying anything electrical / mechanical, I' wasn't ready to open my meter and make any modifications (I've had it less than 24 hours) I also find comfort in knowing its under warranty. However, once the warranty expires ... lookout. BTW, I don't supposed you know the manf & part number of the detent pot you installed. Might not even be a bad idea to send Minelab the details of your modification. They might even be grateful enough to send you some freebies. Since I didn't want to open my meter I went about finding another way.

Borrowing from the rubber band / o-ring idea, and after some experimentation, I used a rubber valve seat from a Delta ball style faucet. I discovered the larger open end of the valve (where the spring is supposed to be inserted) was a perfect snug fit to when stretched (forced) over the locking nut where the pot stem exits the case. The valve is also the perfect length so no cutting is required, and the hole in the smaller end of the valve is a perfect fit over the pot shaft. The diameter at the small end of the valve is the perfect size to present considerable friction to the inside of surface of the knob and prevent it from turning. I've found it to be a good solution, looks good, and will even serve to keep dirt out of the pot. :thumbup

If you're unfamiliar with the Delta sink parts the valve seat they can be seen here: (They're the two small round black things in the background by the tip of the wrench.)

http://www.hardwarestore.com/pop-print/larger-image.asp?product1No=1748

 

[Art (NWOH)]

Wait until you forget to switch back to discriminate after pinpointing. How many targets will you have to hear before you figure out what you forgot to do??

Happens to all of us :lol .

HH

 

[Mike Bearden]

Yeah, I tried every configuration of O ring out there that even looked like it would work. I even used a dab of hot glue where the inner/outter shaft meet and it would still lose calibration.
All I know is that I was constantly having to calibrate the meter and didn't trust it. I hunt by sound 99% of the time anyway but it's nice to have a meter on the questionable targets.
The detent pot I used is a ALPHA ( same as stock) with 2 exceptions. It has a shorter shaft and it's a 10 K. I simply installed it, set the shaft at the midway point and calibrated the meter internally to read silver @ 180. This way if for some reason the knob does get turned ( like when my knob turning little grandson gets ahold of it :lol ) all I have to do is click it back around to the straight up position and it's back at 180 again.
On the meter mount, I simply used a threaded stainless screw front and back to elevate it until I could see the meter without looking over or around the handgrip.
All of this took about an hour to do but it works great and I TRUST the meter now.
Pics to come.
H.H.
Mike

 

[Rick(ND)]

I just did a quick look in my owners manual and didnt see where it said to calibrate the meter in disc mode. I suppose they just figured that most ID with their Sovereigns in disc mode so they didnt even mention it. This is one thing they did overlook like the 170 for a calibration number when it should have been 180.
I havent used one of the new meters, but I know those 550 were very touchy and the numbers would overlap the close ones, but when we rescaled them to 180 numbers they were very stable and it took a little to change them. I use the SunRay DTI meter on my GT and on most of the Sovereigns I had and find the rescaled Minelab 550 meter would stay in calibration better,but I couldnt ID like I could with the SunRay on the close ones. I find that when I turn it on I will put a new dime or a pre 1982 penny on the ground and check my calibration to get a 179-180 before I start hunting. Just get it to stay between those 2 numbers as I find it is hard to just get a 180 everytime and it will not stay anyway. Now I am ready to hunt and if I ever see the meter give me a 182 then I know it is ready to recalibrate as the temp got warmer or the control got bumped. I also knew all my reading will be with in 2 numbers. My good copper and silver and clad was 179-180, my new zinc pennies and IH were 176-177 while 90 % of all screw caps were 177-178 with a slightly differnt tone than a coin. If you run freq 1 on the GT or Elite the nickles would be 147-148, but we find freq 2 works better and nickles will be 144-145 like all the other Sovereigns were.
On the rescaled Minelab 550 meters I found I could wrap a couple of rubber bands around the shaft of the meter and then put the knob back on and it was rare I had to recalibrate and think it was less then 5 times all season as like I say it wasnt as touchy as when it was a 550 meter. The SunRay meter I only calibrated it on the first hunt 3 weeks ago and I havent had to recalibrate yet as it is staying between my 179-180 when testing my coin.
On the meters in all metal pinpoint some wonder what the numbers mean and this too should have been put in the owners manual too. These are intensitiy meters in all metal I call them. If the number change alittle than it is a deeper target, if they change a lot they are surface targets, but you can do the same thing with the audio of the Sovereign in pinpoint as too how weak and how small. I also seen if you have a negitive number when switching to pinpoint those numbers may stay a negitive number and may not change, so I usualy dont pay attention to the numbers in all metal pinpoint.
Good Luck with the Sovereign and get to know it and you will see it is one of the very best there is. :thumbup :minelab

 

[Dan R.]

I have the new gt meter and it sets up very accurate and no bouncing around when placing a target within the coils reach for calibration.

First make sure your not in an area that is affecting responses to your coil other then the target you use to make the calibration. get away from any types of interferences.

You can set the controls to either auto senstivity or some mid point like around 12 oclock or round 1 oclock. Take your quarter if thats what you want to use and set the meter to 180 if that what you choose.

I have my meter set for 170 on a dime and it goes 170 on a quarter also , i can get as high as 171 on the dime or quarter also but no less. I get 139 to 141 on nickels , all pulltabs are higher by several numbers like 148 and higher . Pennies also vary from the clads and silver and come in higher the pulltabs but lower then the clads and silver. 167 and 168.

The detector is very accurate with tones and I use the meter and it lock on very tight if I do the sov wiggle of only an inch to around an inch and a half wide wiggle over targets that may be very near other targets.

The stability of my dete

 

[Dan R.]

I have the new gt meter and it sets up very accurate and no bouncing around when placing a target within the coils reach for calibration.

First make sure your not in an area that is affecting responses to your coil other then the target you use to make the calibration. get away from any types of interferences.

You can set the controls to either auto senstivity or some mid point like around 12 oclock or round 1 oclock. Take your quarter if thats what you want to use and set the meter to 180 if that what you choose.

I have my meter set for 170 on a dime and it goes 170 on a quarter also , I can get as high as 171 on the dime or quarter also but no less. I get 139 to 141 on nickels , all pulltabs are higher by several numbers like 148 and higher . Pennies also vary from the clads and silver and come in higher the pulltabs but lower then the clads and silver. 167 and 168.

The detector is very accurate with tones and I use the meter and it locks on very tight if I do the sov wiggle of only an inch to around an inch and a half wide wiggle over targets that may be very near other targets.

The stability of my detector and what senstivity settings I use are according to the ground I am working. The meter works very good because it seems to follow my adjustments for stability over the ground I set up for. I will get readings in minus numbers that sometimes are in the 400 area when over iron big time but can also wiggle some good targets and solid lock ons for coins even in areas of iron. I find the sov the most accurate detector with numbers I have used up till now, I guess its the bbs thing.

HH

Dan R.

 

[Anonymous]

Hi from down under in New Zealand
I am new at this and hope someone out there can help me. I have an old Minelab Sovereign with type of digital meter on top. Can anyone tell me or have a manual I could buy a copy of about how to use this meter and to understand the readings, there are no numbers shown only a vertical bar that moves from left to right depending on a signal.
Left side has the word normal and right side has expanded, with a mode button (panel) near the bottom.
Any help would be appreciated