Help with coil noise

Hi All, this is my third minelab. Last machine was a 5k which found quite a few pieces and really had a handle on that beast and its settings in various grounds but had to sell it 2 years ago due to being out of work. Now I have full time work again managed to save for a new sdc purchased at reeds last week. This machine is so easy to use, tune etc but I've only got around 4 hours use on it and are getting very fustrated with it falsing about 50% of the time when the skid plate slides on the ground. Typical pilbara mineralized ground and very dry. I've tried running it in normal timing (green selection) and it still occurs but isn't as loud. If I crank it to #5 it barks. Tried all possible fixes, no yawing when pumping coil up and down so its ground balanced, threshold min and max and makes no difference. This machine is less than a week old and in the past when I had this problem it was after market faulty coils that were replaced with no further issues. The sdc
is chirpy but thats just emi and definately not as quiet as my 5k was but still great for a sensitive machine. Is there something that I can do with the settings being a newbie to the sdc? or has there been issues with the coils in the past. Thanks for any feedback

Some have had a problem straight out of the box, if it's less than 14 days old then ask for a full replacement or money refund. You should be able to scrape the coil on the ground without any false signals, and yes they are much more chatty than a 5000, and you should be able to run it on max #5 most of the time, and full threshold/volume.

cheers dave

G'day Bikehe,I've had an SDC for about two years now,after selling my 5000 to "downsize"

There's no doubt the SDC is a cranky little beast when you dial up the sensitivity past 3..you've really gotta be in the zone as it were,to be able to hear the signals with so much chatter going on.
It is a great little machine even when you run the sens right down on 2..it will still pick up the tiny bits.

What I find is try doing a few noise cancels till you get that threshold as smooth as you can..you'll never get it humming like a 5000 but you'll definitely hear a target if you walk over it

Cheers....Dave

Thanks Dave. Don't mind the sensitivity as that's easy to get the ears to tune out. When the coil slides and touches over the ground was getting woohoo sound if that makes sense. Machine is ground balanced, constant smooth hum checking the balance. Did auto tune 4/5 times but made no difference. I've had this situation on wet ground but the soil is dry. Rang a mate who has one and he says you get use to it but been using minelabs for last 10 years and it was always something causing it ie coil cable loose, damp ground, not ground balanced properly, bad plugs etc. Its very frustrating and if this is normal I'm questioning my money spent. I'll give reeds a call tomorrow

Hi Bikehe
Sounds like a faulty coil send it to minelab and they will sort it out,it shouldn't be falsing like that.

Are you placing the coil on the ground when you do the tune?

Not at all. I've tried it at elbow height horizontally Tried it just above ground level and EMI noise seems to be at a minimum where I'm happy with either method. Would that affect the coil falsing in any way?

Morning Bikehe,
Have never understood why Minelab always include in their manuals the tuning instruction whereby the machine is held at waist height to tune.
Discovered back in the days of the 2100 that laying the machine on the ground and going through tuning procedure was always more effective.
Someone with a lot more experience may be able to explain this better?
Anyway it is worth your while giving this method a trial.

Hi Nightjar, totally agree. IMO and it's just my thoughts only, there are 10 ways to do the right thing. With auto tune no matter the machine I do a noise cancel a few ways. It all depends on where the EMI is coming from. There are many different types of EMI being generated. Theres telstra towers, mining company relay towers etc etc. In the pilbara with iron stone hills the noise can be deflecting at different angles so depending on this will depend on which method of auto tune works the best. I use to crank the grain to 20 on the 5k, do a 360 with coil in the air and find the noisiest direction then auto tune. Sometimes this method worked then other times hold coil 2-3 ft off ground and auto tune to get the quietest channel. I would do this 6 times in a full days detecting minimum to keep it quiet. It all depends and that's not to mention whats going on with atmospheric conditions added to the equation like static, lightning. Anyway 10 ways will work depending on where the EMI is most directed at the coill. As for SDC I phone minelab and they said it shouldn't be falsing after I explained what I and the machine were doing. They said to take it back to Reeds on Wednesday for a new one as it's only a week old. See how the new one goes.

bikehe wrote:As for SDC I phone minelab and they said it shouldn't be falsing after I explained what I and the machine were doing. They said to take it back to Reeds on Wednesday for a new one as it's only a week old. See how the new one goes.

That was my advice, when your first post explained what it was doing.

cheers dave

Good advice Dave. Thx

Went for another swing today to make the most of it before taking detector back to dealer and something totally different happened. Turned machine on then went to do an auto tune and nothing happened. Noticed no threshold LED's up either. Tried adjusting the threshold and nothing. No red LED's, no auto tune function. The key pad has gone totally dead. Must say I'm not feeling very confident in a replacement unit. Thought the SDC was a solid constructed detector. Surely QC isn't that bad. I had to get the lemon Grrrr

take it back for a full replacement. we had the same last year

G'day bikehe

Whether through human error or the breakdown of an electrical/electronic component, s**t happens & we've all experienced some form of it in the past. One can buy an expensive television in the $1000s & still have it malfunction within the first week/month of use. That's electronics for you.
As long as the faults/breakdowns occur within the warranty period, all you can do is send it back for replacement or repair. I know both Minelab & our various coil manufactures have been & are more than honourable with their warranties, its just a shame we have to put up with the inconvenience.

Cheers Kon.

Good news, took the sdc into reeds. They couldn't get the falsing ro happen and the keypad powered up as normal, typical. Luckily I made video of falsing and the keypad dying which was my saving grace. Anyway after. Reeds phoned minelab in SA it was agreed to give me a replacement new one. The service was great and couldn't be happier with the outcome. Happy days.

Great outcome, nothing better than customer service.