Sovereign GT erratic behavior

[coinhoundNJ]

Hi everyone and thank you for accepting me into this great forum!

I am a relatively new Sovereign GT user. I have used Whites 5000's and a Tesoro detector in the past. I have two GTs now. I bought two used but practically new GTs with warranties on eBay after learning that the detectors were being discontinued. One is set up for inland use with a Ron 180 meter and SunRay S-1 probe. The other one is set up with hip/chest mount, a Ron 180 meter and a Coiltek 15" WOT coil for beach and shallow water hunting. I have a RCA extension cord on the 180 meter so I can attach the meter to the hip bag to keep away from water.

I have been going to a local ball field hunting for coins with fairly good success using the stock 10" BBS Tornado coil. This ball field is located in a park dating back to the late 1880s. Strangely I have only found clad coins and the older coins are eluding me so far. Only time will tell if I can locate the "hot spots" and perhaps enlisting the help of the WOT coil would be a good idea also. However when I find aluminum lids from Pringles cans at 8" this is disturbing. Sometimes the top of an aluminum beer can reads 180 on my meter. Other wise the meter is tested and calibrated correctly and works very well. The SunRay probe is also fantastic and I dont leave home without it!

The last time I was out the Ron meter was behaving strangely, never getting above 1.0. Also the detector was producing all sorts of signals when I am not even moving. I switched out the meter. I stand still holding the detector coil at waist height and the meter is reading all sorts of values. The detector settings were disc on, disc 3, notch 0, volume max, sens auto, threshhold six. The troubleshooting section of the manual says to check battery. All batteries have been fully charged and I could find no loose connections. Perhaps the NiMh battery pack did not click in properly. My outing that day was sadly ended. Today I have to test at home both detectors for a sanity check to see if the problem repeats itself. I will also get a voltmeter to test the charge on the battery packs.

Anyone who has similar experience with erratic behavior of the GT and/or the Ron 180 meter, this would be helpful.

George in NJ

 

[rl48off]

change the RCA cord that may be the problem

 

[xwyokid]

I had a similiar problem when I first got the meter. For me it was a bad extension cord from RS. Went back they gave me another and it was fine.

 

[deepdiger60]

I have to agree the RCA cord is doing it i had the same problem changed it and it was fine . Jim

 

[coinhoundNJ]

Thanks for the advice on the meter. I will provide a follow up. New Jersey environment has been less friendly lately for detectorists. Today it is snowing.

 

[Critterhunter]

If just the meter was acting wild while the threshold was stable, then for sure it probably was the RCA cord. If, however, the threshold was going crazy then my guess is EMI noise. Auto sensitivity won't always cure that. Try the lowest manual setting (all the way to the right with the dial) and see if the machine stabilizes. If it does then it's EMI. Continue to raise the sensitivity until it begins to act up again, then flip over to the other noise band and see if it once again stabilizes. If it does, continue to raise sensitivity until it just starts acting up again and back it off a hair. You've now found the highest sensitivity setting, and the noise band that allows the highest for the EMI in the area. Almost all of us use band 2 as that matches the ID charts (older Soveregins were locked into band 2), but I will switch to band 1 in some areas if it improves stability and allows higher sensitivity settings. All depends on the EMI type in the area.

 

[Critterhunter]

Forgot to add another tip on this. First, if the coil held still and in the air is making the machine unstable, with the threshold resetting or dropping out or chattering, then that is an EMI issue. If, however, the machine only gets eratic or nulls as you sweep around, but is fine when held still, then that tells you the sensitivity isn't too high for EMI, but it is too high for the minerals at the site.

How do you know if the nulling is minerals or if it's nulling on iron? Sweep over the same exact spot on the ground where it nulled. Is it nulling every time? Then it's iron. Only sometimes? Too high of sensitivity then. Try lowering it and see if it goes away in that spot. However, before lowering sensitivity, try slowing down your sweep speed. If you sweep too fast it can be too fast for the given sensitivity setting and the threshold is losing track with the ground due to how fast you are sweeping.

Also, in order to check the machine for a problem, you need to be far away from houses or power lines. EMI will cause an eratic meter, but at the same time it will also cause the threshold to null or chatter. As said, auto sensitivity won't always fix this, but a low manual setting will.

If the machine is still acting up far away from EMI, then start at the coil and slowly work your way up the coil cable wiggling the wire every few inches or so. Do you hear the EMI suddenly get bad or better? Then you've got a coil cable short. Look for those in particular either right above the coil or right behind the plug where it plugs into the detector or meter.

If your battery was bad, chances are you'd be hearing a loud siren every 30 seconds or so, indicating the low battery alarm.

 

[coinhoundNJ]

Thanks very much Critterhunter!

What you wrote is very interesting and very good advice. Its like I got into a patch of ground or an area where the detector just acted up and didnt want to settle down at all. Its funny, I am standing there with the coil at waist height, detector acting up and wondering what on earth got into my machine. Never got that before, very strange and very frustrating. I will print out your comments and just go to a clean place for a baseline check with some tests and then back to where this happened and see if the detector behaves the same way again.

 

[bootyhoundpa]

ive had simular experience in one small section of a park.... i atributed to underground wiring feed the light poles.......

 

[Rick(ND)]

First thing I would do when you have this kind of a problem is to disconnect the meter ans see what the GT will do with just the coil hooked up to the control box as it comes from Minelab, so there is nothing else hooked up to see if it is the detector or coil problem. If it works OK then you know there is something with the cable or meter. If it still does it then you know it is the detector, the coil or even I have seen where the cable plugs into the control housing being lose and not giving a good connection as the cable connector has to be tight where it goes into the control housing. Now if none of this helps I would disconnect the cable from the control housing and turn on the GT and see if it will run smooth, if it does then you know the problem has to be in the coil or cable, so if you have another coil put it on and see if it will run smooth now.


Rick

 

[Critterhunter]

Also, unplug the coil cable and look at the pins on the cable's plug. Are they only slightly open, and will expand when the control box pins push inside of them? If you see any that are gapped way far apart then try poking them back together a bit and see if that fixes it.

When I traded my 15x12 for a 12x10, I knew the 12x10 had a short in the coil cable from the owner, so they gave me $50 to make the even trade. That was only under the condition that indeed there was a short in the cable, because I could fix that. When I plugged in the 12x10 it did exactly as you describe above, and when I worked my way up the cable I found it was causing the problem right at the plug when I wiggled it.

Turned out it did have a short right at the back of the plug, because that's were they usually happen, especially if people hip or chest mounting don't loop the cable in a belt loop or something to take stress off the plug's backside right at where the cable hooks up to it.

Anyway, I did find a short in one of the wires and re-soldered/fixed, and heat shrinked it. But the coil was stick acting up! I couldn't figure that out, because I had used an ohm meter to test the wires were they were soldered to the back side of the plug pins, and then touched the other lead to the other side of each pin where they plug into the control box, and each was giving me just about zero resistance, meaning no short (infinite resistance means there is a short, or even a higher than say a few ohms).

So I took off the heat shrink again and started wiggling at the back side of the pins, and darn if one didn't break right off. As I was punching that pin out to replace with one from a similar plug I got at Radio Shack, another pin fell right out too! Turned out like 3 or so of the pins were cracked inside the plug from somebody trying to repair them with too much heat (not me, I only fixed one anyway I think). I think somebody probably was soldering those puppies with a propane torch, which is way too hot for that thin of metal. So anyway, knocked the 2 or 3 out that were bad and punched in replacements. The plugs at radio shack didn't have the right number of pins, otherwise I would have just swapped plugs, but the pins were ones I could use to replace the bad ones with.

Long story longer...Unscrew the coil cable from the control box. Then wiggle it a bit and maybe pull it slightly in/out. If the problem shows up or goes away then you might have a bad pin. That's the only way to tell short of pulling the heat shrink off and wiggling the pins from the back while somebody also reads the front and back of them with a volt meter, to see if any are cracked inside the plug. More than likely though if you've got a coil problem it's a short in the cable right behind the plug and not the pins, or in the cable right above the coil. I doubt it though. I'm betting your problem is just EMI in the area where it acted up.

 

[Ron from Michigan]

Will take a look at the meter and cord if you ship it to me,could have it back in a couple of days.HH Ron

 

[Rick(ND)]

I had a hard time finding them, so when I did I beleive I got 25 or so of them for those that need them.

 

[coinhoundNJ]

Thanks for the tip. Looks like the weather is going to be good this weekend in NJ so I will back out running through some tests. Both Ron meters that I purchased are practically brand new so I doubt there are any problems. I have two detectors so I can swap the meters out as well as coils and eliminate issues that way. If I suspect a short or anomaly with any of the meters I will let Ron know. But I also like you suspect the problem is related to the detector and a possible EMI or ground interference issue. If the erratic behavior returns the first thing I will do is drop the sensitivity down and see what happens.

 

[Critterhunter]

I had a hard time finding them, so when I did I beleive I got 25 or so of them for those that need them.

Hey Rick, that is very gracious of you and I thank you for the offer. I think I'm good right now though, since I was able to replace bad pins on the 12x10 by knocking them out and using ones pulled from a similar plug from Radio Shack. Unless I have a plug's threads or something go bad on the plug it's self I should be good to go on fixing any future plug problems on coils by transplanting pins.

I think Ism found a cheap source for plugs too, and if I remember right he said they had better pins then the ones that came on the SEFs, because I think he too had an issue with the pins cracking at the back side of the plug due to stress. That source/thread link I think is in the coil sticky somewhere from him.

Not that the plug is a real problem with the SEF coils. The person I bought my coil from chest mounted and told me the coil had a short in it before I traded them my 15x12 for it, and they had also screwed up a few S-12 coil cables for the same reason I suspect (chest mounting without looping the coil cable to take stress off the plug area). But I also noticed the SEF coil pins are very thin at the back end where they are soldered, and I think somebody attempted to repair them with too much heat when I fixed mine.

Again, thanks for that kind offer Rick. If down the road I need a few maybe I'll shoot you a PM and trade you something in return for them. Got a ton of heat shrink tubing laying around for one thing. Or if you ever need any 9V regulators I think a buddy of mine dropped me off a handfull a while back for a project I was working on if I can find them.

 

[coinhoundNJ]

I was out in the field on Saturday 11/10 in the same area. I had my hip mounted GT with 10" Tornado coil and 180 meter. No problems at all with detector fluctuation or EMI that I could see. I did find that one 180 meter was reading less than 1 or 0.00 so Ron is going to send a replacement. I will check my other GT in that area next time.

I had a great morning finding over $6 in clad coins in about 2 1/2 hours. One hole I found almost $2 in change. Must have all fallen out of someone's pocket. Two or three other holes I find two clad quarters in each.

I tried out the Garrette Pro Pointer that I bought. It is small, compact, and very sensitive! Very easy to use. It is VERY sensitive, picks up the eyelets in my boots and anything else that gets too close. I highly recommend the Pro Pointer. I also use a Sunray S-1 probe on my shaft mounted GT which I like very much also.


George

 

[Critterhunter]

Yep, just about everybody uses the Pro Pointer. Best hand held on the market most people think. I know I love mine.

Got a related EMI story for you- A friend had recently bought an Excalibur and was having issues with it going bonkers at a site out of no where on several different days. He was suspecting the machine was bad. Then another friend at the same location had the same problem.

Just the other day I was at the site and my GT went bonkers on me all of a sudden. Looked at the clock on my cell phone and it was right around the time my friends reported their issues with instability (around 5PM).

I'm suspecting there is something nearby turning on at the same time every night, like perhaps an electric invisible dog fence or a security system. Even in pin point mode it was making a up and down humming noise like a force field on Star Trek or some other sci fi show. Never saw PP mode do that even at full sensitivity I've been playing with lately. It's always been rock solid even in the worst of grounds so far.

Either way, I called the one friend who had just bought the Excalibur to tell him the problem with his machine was probably a randomly occuring EMI thing and not something wrong with the machine, but I told him to hunt with it some more at a few other sites so if it really does have some kind of issue he can find out and send it in to get fixed and not wait to spring to find out.