SDC2300 and Earth magnet interference???

[Gully]

Went out today and found my sdc not running smooth, re channelled several times, ground balanced, tried heaps of other settings but could not get it to settle like usually. The only thing I could put it down to was a new earth magnet I bought that was on the head of my pick I was carrying. They are pretty damn strong and was warned to keep it away from my phone and electronic devices, I wonder if this was the cause?? The detector did settle but it was a few frustrating hours finding hard to even hear lead amongst the noise. Anyone have any thoughts?

 

[hAyyoUinAU]

It shouldn't pick it up at a fair distance. Leave pick on ground with magnet..walk away and try noise cancel again. If it is quiet and gets noisy as you head towards your pick, problem solved.

I never use a magnet at all though.

I'm expecting gold every time I dig. lol

 

[Dron]

I keep my rare earth magnet on a bungee cord attached to my shoulder and it doesn't interfere unless it falls down and swings around the control box.

It could have been EMI, was it a windy day? How far from civilisation were you?

Metal on your clothing or shoes?

 

[Heatho]

I've had my SDC misbehave before like this, some days the emi is just plane nasty. I remember one time I did about 6 or 7 noise cancels and it still didn't settle. I stopped for lunch went back out a couple of hours later did another noise cancel and it was perfect. I don't think it would have been the magnet if it was a decent distance from the detector.

 

[BillS]

I've had my SDC misbehave before like this, some days the emi is just plane nasty. I remember one time I did about 6 or 7 noise cancels and it still didn't settle. I stopped for lunch went back out a couple of hours later did another noise cancel and it was perfect. I don't think it would have been the magnet if it was a decent distance from the detector.

I have been out on days and had similar experiences. Noisy unable to find targets, a couple of times found the skid plate had worn and dirt had worked under it giving false signals and could not get the machine to runs stable.
Also water under the skid plate can cause falsing and EMI.

 

[Syndyne]

Agree with BillS above. Check your skid plate now and again and make sure it's clean and free of debris :Y:

I also use a rare earth magnet on the blade end of my pick. Used it since the first week of the SDC's release and have used it with the Zed over several weeks with no issue. Unless you have it right next to your coil when ground balancing I can't really see a potential problem in using one.

If the skid plate is all good then I'd be more inclined to think it was possibly atmospheric/outside interference if you've done everything correctly as far as the general startup sequence goes. Other than the more suspect, obvious causes such as close mobile/radio transmission towers, power lines etc. you will also find wind and enhanced solar activity will cause a bad day(s) on an SDC.

The strangest form of interference we have encountered was construction works on a granite dam. Every time the hydraulic hammer on the excavator would start punching the SDC would go crazy. We quickly figured that the static created on those big steel hammer tips must be huge at times! They were working about three-ish kilometres away line of sight.

Hope you get it sorted without too many dramas Gully.

Cheers,
Shauno.

 

[Heatho]

I remember that Shauno, that excavator caused absolute havoc for us.

 

[Syndyne]

I remember that Shauno, that excavator caused absolute havoc for us.

Definitely a head scratcher on that first morning for sure! I would've put money on it being the wet grass getting moisture inside the coil cover. Easy to rule it out though once it all dried up mid morning and still continued to interfere.

Usually a quick process of elimination will sort out an EMI problem. The only time it get's tricky to nut out is when the Sun flares up a CME over a few days.

All part of the fun

 

[Northeast]

Were you near any fences Gully?? Electric fences are a mongrel for making the Z go bananas. I've been told it is the same with P.I's.

I didn't know I was near an electric fence the first time it happened. Noise cancel did nothing to improve it. As I moved about it would get better or worse but as I wasn't near a fence I didn't equate it to that. It was the next time I was out there that I started the detector up only about 30 metres from the fence and it was obvious what it was. Walked closer, got worse. Walked away, got better.

I didn't measure it but I reckon it was about 200 metres from the fence before the interference was completely gone.

 

[BigWave]

You're spot on with the sources of EMI Shauno.
I would add in aircraft approaches and departures though.
I check the BOM site for solar alerts (CMEs) before heading out as well.
http://www.sws.bom.gov.au/Geophysical/2/1
If you want to visualise, use the Canberra Magnetogram (at least for Vic and NSW as other sites are pretty crappy - poor scales).

 

[Ridge Runner]

Went out today and found my sdc not running smooth, re channelled several times, ground balanced, tried heaps of other settings but could not get it to settle like usually. The only thing I could put it down to was a new earth magnet I bought that was on the head of my pick I was carrying. They are pretty damn strong and was warned to keep it away from my phone and electronic devices, I wonder if this was the cause?? The detector did settle but it was a few frustrating hours finding hard to even hear lead amongst the noise. Anyone have any thoughts?

Depending on the Coil I am using one of my machines will pick up me swinging my pick at huge distances, but I think your troubles are most likely what the other guys said,

J.

 

[Reeks]

I swear one day I heard a pilot talking very briefly in my headphones when a plane was flying overhead at Hill End :|

 

[Ridge Runner]

I swear one day I heard a pilot talking very briefly in my headphones when a plane was flying overhead at Hill End :|

That was the MIB

 

[Gully]

Lol thanks for all the replies, headed out today and left the magnet in the car....same issue, could not get it to run smooth like usual. Noise canceled At least 10 times, ground balance and all other tricks but no joy. Pretty sure no elec fences are nearby within at least a km. Will have to start reading into the solar thing as I do find it runs smoother later in the day for some reason???

 

[Heatho]

Another way I noise cancel sometimes is to turn around with the SDC out in front of me until the emi is loudest and then lay it on the ground with the coil sitting up at 90 degrees and then press the noise cancel button, for some reason sometimes that will work for mine.

Hope you get the issue sorted out.

 

[hAyyoUinAU]

Try a different location.

If you still have problems, you might have a faulty SDC.

 

[Syndyne]

Try a different location.

If you still have problems, you might have a faulty SDC.

Good call! I was going to mention that last night along with possibly meeting up with someone that owns an SDC and comparing in the same locations. The other thing I was going to mention (though most of us pretty much know this) is to keep the mobile phone off (or on airplane mode). I generally just leave it off and in the car.

I swear one day I heard a pilot talking very briefly in my headphones when a plane was flying overhead at Hill End :|

lol! *cue the X-Files theme*