Whites SPP Hiccup Video

[Roscoe]

This is a video Demonstrating the Hiccup sound made by the Whites SPP PI metal detector. Got up early this morning and there was a lot of wind. So i couldn't do a sweeping the coil demonstration. I tried to hook up a booster speaker so as to increase sound for sweeping demo, but had problems because of the 1/4" plug was wired different to the SPP. I have no editing software so i had to down load three separate videos.





I have one more video to follow and that's with a gain of 8 on 12" whites coil.

 

[Roscoe]

Gain at 8 on SPP with 12" Whites mono coil.

 

[Ben78]

"this video is private"

 

[Roscoe]

Does it work now?

 

[Guest]

Yep works' straight shaft looks good!

 

[Roscoe]

Thanks Zuke, First time i operated this video camera and first time uploading to YouTube. To say i was a bit stressed this morning trying to get these video's done was an under statement. Well i am glad they work and the stright shaft feels better to.

Thanks Ben78 as well.

 

[Homebrewer]

Taken at Amherst today.

Sorry about not editing it, but the hiccup is clearly heard.

 

[Roscoe]

Thanks for posting homebrewer.

 

[Reg]

Roscoe,

Do you get the hiccup anywhere you try raising and lowering the coil or only in some places?

Now, in areas where the ground is flat and you are keeping the coil level, the hiccup signal is telling you something is there. It could be a rock a piece of metal or who knows. The hiccup can only occur because of a sudden change in signal characteristics.

Something else you don't know and that is, the ground canceling circuitry has a gain of 30 to 50 times that of the normal target signal. So, signals that are too weak to be detected as a target can create a hiccup via the ground channel.

Ground canceling occurs when you take two signals and subtract one from another. A target signal is taken but it also has ground signals that interfere. Now, a later signal is taken and then amplified a bunch until the ground signal in that channel is equal to the ground signal in the main target channel and the ground channel is subtracted from the main channel. IF the ground signals are equal in the two channels, then the ground signal changes little to not at all.

However, because the ground channel has so much more gain that it can cause signals to appear sort of like hiccup signals.

So, if you are not raising the coil quickly, then something in the ground is causing the response. Just what that object is, I can't say.

Just for fun, you might try digging some of the odd signals. I found initially that even gold buried too deep for detection with a normal signal can cause a hiccup response.

Reg

 

[old hand]

Reg the hiccup occurs when ever we ground balance its always on the up stroke and their are no targets in the ground

 

[Guest]

Maybe that's why I don't see such a issue with the hiccup' when I GB I only have ever done short little bobs whilst I slowly turn up the GB dial once I hear the low tone I stop and set it between the low tone and high tone' like tuning into the sweet spot on a AM radio.
I could get the hiccup if I lifted the coil maybe 4" from the ground and I do get the hiccup if I come across a hot rock or hot clay pocket but once dug up it's gone. I am using razorback coils with excellent shielding and the areas iv tried may not have been as hot as other people are working' but the gp 3000 would not work with a mono without a GB every few feet so that has got to put the ground in the hot catagory. I'd have to agree with Reg the hiccup is caused by some sort of target response.
I might build a DD coil just to see if it works just for the bad hot areas.

 

[dazza513]

I must have been in a paddock of hot rocks!

 

[old hand]

that's the easiest way to get the hiccup just lifting the coil up and down if it only did it then I could live with that ,but when you are sweeping the ground and its hiccupping most of the time as dazza said he had to walk away from the area. regards john

 

[Guest]

I don't seem to have that kind of dramas yet' but I also have fitted the conductivity switch as I use it a lot on the TDI pro and in LOW ignores a lot of ground noise.
I realise fitting the switch isn't the answer to the hiccup but it will help a lot.

 

[old hand]

At this stage I am going to see what Whites come back with thanks regards john

 

[Roscoe]

Zuke, I have done shorts bobs, long bobs, slow bobs, fast bobs and every thing in between and there is no Ground balance method on earth that will prevent that hiccup.

Reg, You are right it the fact that the detector is signaling on some thing, unfortunately its the ground minerals for us.

Reg, to answer your questions mate.

1-The hiccup occurs when ground balancing every where, there is no location it does not.

2- I have operated it on flat ground with coil to the ground at all times it will still give you a hiccup sound.

3- I am not raising the coil at all when sweeping, my coil never leaves the ground (I am a scrubber)

4- I don't normally raise the coil whilst balancing as fast as in the videos, I did this because i had to demonstrate the hiccup with the external speaker and the morning was windy. Even if you raise the coil slowly it will still hiccup, its just a lot more noticeable in the headphones. If i raised the coil really slowly then it may not hiccup, but to detect at this speed would not be practical.

The plain fact of the mater is that the SPP can not handle our soils over here in its current form. Some changes will have to be made to its internal operation to fix the problem. In the mean time i will have to put up with the hiccup until a more permanent fix is found.

 

[Guest]

Other than the conductivity switch the only thing I'm doing different is using razorback coils? So if I'm not having that big of issue using razorback coils a DD built to suit the machine should work fine in bad areas

 

[Roscoe]

I agree a purpose build DD coil would be good thing, it would be good to test a purpose built DD coil for the hiccup.

 

[dazza513]

i've been mainly around the rushworth area and for 90% of my detecting there the spp has behaved really good (gain at 7-8 and ground balancing well near preset mark) and only the occational hiccup.

but then I find the hiccups start to really hit hard in some areas(lots of fine red stone), best described as a droning threshold from 1 hiccup to another, change battries, re ground balance, back the gain down to 5, adjust frequency.... (im a coil scraper)

then walk back 5-10 meters to where it first started playing up and the spp will run quiet as a mouse.

no emi that I know of so I can only put it down to the ground itself in some areas on that gold field.

With that said I was still able to detect in 90% of where I wanted with the spp doing really good

Regards Daryl

tried my dads x-terra on the same ground and was still able to ping a shotgun pellet?

 

[Roscoe]

What coil did you use Dazza? Did you find any gold?