Vallon VMH3CS Mine Detector

[Carolina]

Eric: Somewhere I saw an elipticle coil you had wound in a clam shell style body. Could you modify the coil inside one of those shells to be 2" x 10" mono and would that give him the knife blade effect I think he wants and would it have any depth?

Carolina

[kingswood]

Here is a picture of the samples. Those that jump to a magnet on the left. Those that have little or no attraction on the right. Those on the left also give a strong deflection on a compass needle, although they may have aquired remanent magnetism when I separated them.

Eric.

Close to Mount Magnet so its not coincidence

[Ferric Toes]

Hot Rocks

Here is a picture of the samples. Those that jump to a magnet on the left. Those that have little or no attraction on the right. Those on the left also give a strong deflection on a compass needle, although they may have aquired remanent magnetism when I separated them.

Eric.

[Ferric Toes]

Interesting observation Eric, I have kept a small collection of hot rocks from Victoria and New South Wales the other 100,000 I've thrown away.
But on quick inspection they are mostly dark and vary in composition from molten iron stone, a sort of layered iron stone , to a conglomerate of iron stone mixed with small and large bits of quartz
but are all magnetic as I picked them up with the magnet on the end of my pick, btw all found with a 4500.

I have just separated Kingswood's hot rocks into those that stick to a magnet and those that don't. I will post a picture shortly as I can now predict by just looking as to which is which as they definitely have a different appearance. I smashed one of those that did stick and it completely shattered, but the bits all stuck together magnetically. Maybe I magnetised it in doing the sorting. This appears to have altered the magnetic decay curve too i.e. made it stronger. I will run all the samples through a demagnetiser before doing more measurements. I get the impression that the non-stick rocks will also be harder to smash as they have more of a meteoric appearance.

Eric.

[Ferric Toes]

The Vallon needs a DD !!!!

I doubt that will happen as it was tricky enough getting a mono to work. You would need to separate the TX from the RX then find a way of introducing another cable for the RX coil. Having done all that, there could be a problem with the programming and the GB. First, someone, not me, would need to draw up a full schematic to see what we are up against.

Eric.

[6666]

I know this story very well ha ha....I usually smash them open just to make sure there is no gold hiding inside....slow process...detect rock, smash rock, throw rock fragments in disgust, repeat !!!

Yes its worth doing recently I found in NSW a small magnetic iron stone rock with the 4500, which had gold inside, the rock was already broken and you could see the gold, but it was obviously fully covered once.

[kingswood]

the other 10,000 I've thrown away.

I know this story very well ha ha....I usually smash them open just to make sure there is no gold hiding inside....slow process...detect rock, smash rock, throw rock fragments in disgust, repeat !!!

[6666]

Interesting observation Eric, I have kept a small collection of hot rocks from Victoria and New South Wales the other 100,000 I've thrown away.
But on quick inspection they are mostly dark and vary in composition from molten iron stone, a sort of layered iron stone , to a conglomerate of iron stone mixed with small and large bits of quartz
but are all magnetic as I picked them up with the magnet on the end of my pick, btw all found with a 4500.

[kingswood]

There is something odd about those hot rock samples. There are the dark brown ones and then some lighter colour ones. If you balance out the lighter colour ones, the dark ones still detect. The same in reverse also happens. The lighter ones are quite strongly attracted to a magnet while only weakly to the dark variety. I will measure the decay curves later as it appears that there must be a difference. Normally, for most iron mineralised soils and rocks, the decay is the same. It is only the amplitude that changes.

Eric.

Thats interesting!....They all came from the one spot, ironically a place where I know gold is
It is an old paleo-channel. It is the only place so far where the Vallon is a pain to use!....Some places have the odd hot rock, but at this spot, its a hot rock every few metres
I have tried GB over a hot rock, but then as soon as you start swinging the machine is just sounding off on everything else.
I have also noted (as you would know by the samples I posted!) size of rock has no bearing on the signal....some small ones scream on the Vallon!
I have used the SDC2300 at the spot and it is okay, only gets the odd rock. Have used the 2000 also, with the DD its fine, but with the mono the only way its almost happy is to use search channel one (which I understand is the longest pulse), if I GB both channels on the 2000 with the mono, its unstable too.
My friend with the 7000 has dug a few hot rocks too.
Nasty nasty area, but there is gold there ....
I will try decreasing the sensitivity on Friday and see if that helps. The Vallon needs a DD !!!!

[Ferric Toes]

I have just had a thought!
After spending lots of time with the Vallon in the area with lots of mineralization, I was becoming a bit jaded, after struggling with GB and also with many many hot rocks!....Then it occurred to me that I havent tried reducing the sensitivity down a bit!....Silly me !!!
I have Friday off so am heading out and will try that to see if it helps.
I did run the modified SD2000 with a 14" mono on it a week ago in the same area and had similar issues.....Hot rocks, hot rocks and more hot rocks!....The big DD I have worked well and seemed to ignore many of the rocks.
Still no gold...but its out there!

There is something odd about those hot rock samples. There are the dark brown ones and then some lighter colour ones. If you balance out the lighter colour ones, the dark ones still detect. The same in reverse also happens. The lighter ones are quite strongly attracted to a magnet while only weakly to the dark variety. I will measure the decay curves later as it appears that there must be a difference. Normally, for most iron mineralised soils and rocks, the decay is the same. It is only the amplitude that changes.

Eric.

[6666]

I have just had a thought!
After spending lots of time with the Vallon in the area with lots of mineralization, I was becoming a bit jaded, after struggling with GB and also with many many hot rocks!....Then it occurred to me that I havent tried reducing the sensitivity down a bit!....Silly me !!!
I have Friday off so am heading out and will try that to see if it helps.
I did run the modified SD2000 with a 14" mono on it a week ago in the same area and had similar issues.....Hot rocks, hot rocks and more hot rocks!....The big DD I have worked well and seemed to ignore many of the rocks.
Still no gold...but its out there!

Good luck

[kingswood]

I have just had a thought!
After spending lots of time with the Vallon in the area with lots of mineralization, I was becoming a bit jaded, after struggling with GB and also with many many hot rocks!....Then it occurred to me that I havent tried reducing the sensitivity down a bit!....Silly me !!!
I have Friday off so am heading out and will try that to see if it helps.
I did run the modified SD2000 with a 14" mono on it a week ago in the same area and had similar issues.....Hot rocks, hot rocks and more hot rocks!....The big DD I have worked well and seemed to ignore many of the rocks.
Still no gold...but its out there!

[chevesne]

To remove the rotary switch:
Place it in the earphone volume adjustment position, lock the shaft with a pliers and unscrew the nut.


The rotary contactor connections are:





I replace it with switches with waterproof caps.



Thanks again Eric.

[Ferric Toes]

The Man with the Hat

Not totally related to Vallon detectors except that Steve, the man with the hat, is staying at our next door apartment which we have as a holiday let for guests. He and his wife arrived just as I was making some adjustments to the reboxed Vallon on our outside decking. His interest quickly showed and he said that he was attending a local detectorists rally just a few miles up the road. I had heard nothing of this, which is a pity as I would have pre-booked. Unfortunately, it is not something that you can just turn up on the day.
When he came back on Saturday evening he said that he hadn't been able to do any detecting himself for the following reason. Have a look at 'The Man with the Hat' on YouTube and you will see why. Look for two live streaming videos taken yesterday, 2nd September. This morning it is pouring with rain but his car is gone so I wonder if he will be able to switch his detector on today.

Eric.

[chevesne]

Thank you Eric.
Some troubles with internet connexion, have to answer later.