Vallon VMH3CS Mine Detector

[Qiaozhi]

Err... any PI emitting both polarities may hardly qualify as a standard PI. Adding the transmission charge kick, an interesting phenomenon indicating sampling waaaay within a flyback, a mH coil finding rice-sized pieces of metal, and a fact it works for hours on less than 2 pounds of batteries...
No. It most definitely is not a standard PI.
From such a machine you may expect a trick or two beyond the ordinary.

That is exactly why I added the proviso: "... I mean that it works in a conventional PI manner ... although there's nothing conventional in the way it achieves the results that it does.", which you left out of your quote.

[Davor]

I don't think we'll learn all it can do any time soon. Perhaps it is not a good idea to try mimicking what it does either. It may serve as an inspiration to try something else.
My relationship with Vallon was brief and memorable. It is simply a great machine. Balance, weight, vibration, handy control... it is a completely another league.

[Ferric Toes]

I don't think we'll learn all it can do any time soon. Perhaps it is not a good idea to try mimicking what it does either. It may serve as an inspiration to try something else.
My relationship with Vallon was brief and memorable. It is simply a great machine. Balance, weight, vibration, handy control... it is a completely another league.

That is why I am fascinated by it. We may not know exactly what is going on inside that internal silver box, but whatever it is can be put to good use in land, beach and shallow waterhunting. As has been said, it has very good response to small metallic objects; very good ground balance; very stable and easy to use once you get your head round the various setting that are possible. I can now make alternative coil sizes and shapes that work and have adapted the high impedance piezo audio for ordinary phones. Next on the list is to make these alternative size coils easily interchangeable with the stock Vallon one. That project is coming along nicely, as is a clear, illustrated, instruction book to show how the VMH3CS can be set up for hobby use.

Buying used units, restoring them and sometimes repackaging the innards, developing accessories, doing field tests etc. is as much fun as developing circuits ever was. And I don't have to worry about infringing any patents.

Eric.

[Mdtoday]

That is why I am fascinated by it. We may not know exactly what is going on inside that internal silver box, but whatever it is can be put to good use in land, beach and shallow waterhunting. As has been said, it has very good response to small metallic objects; very good ground balance; very stable and easy to use once you get your head round the various setting that are possible. I can now make alternative coil sizes and shapes that work and have adapted the high impedance piezo audio for ordinary phones. Next on the list is to make these alternative size coils easily interchangeable with the stock Vallon one. That project is coming along nicely, as is a clear, illustrated, instruction book to show how the VMH3CS can be set up for hobby use.

Buying used units, restoring them and sometimes repackaging the innards, developing accessories, doing field tests etc. is as much fun as developing circuits ever was. And I don't have to worry about infringing any patents.

Eric.

Excellent work Eric, great thread, thank you for sharing your knowledge, it is much appreciated.
Can't half tell you are enjoying it

Brian

[kingswood]

The ability of the Vallon to find the smallest scrap of wire you can find never ceases to amaze me.
Dug up 3 tiny flecks that I could barely find in the scoop and a bit of old aluminium foil that had me thinking it was gold at an inch.
Did have a bit of an issue with hot rocks today...new area so maybe just more than usual.
I invested in an old SD2000 (with mods) that I tried out yesterday....With that and the wife's 2300, we have quite a collection happening here!
I must admit that out of them all, the Vallon is by far my favourite to swing...ergonomically just about perfect ...and I like that you can shove the standard coil in and under shrubs!
Gold will come soon hopefully !!!

[daverave]

i went to local beach with the vallon a few days ago and its depth still amazes me..it detected an old english half penny at about 16" and tiny pieces of metal at good depth...i think with the coils that eric is developing the vallon is going to be a real killer on the beach and for
nugget hunting....all at the fraction of the cost of say a garrett atx.

[Mdtoday]

The ability of the Vallon to find the smallest scrap of wire you can find never ceases to amaze me.
Dug up 3 tiny flecks that I could barely find in the scoop and a bit of old aluminium foil that had me thinking it was gold at an inch.
Did have a bit of an issue with hot rocks today...new area so maybe just more than usual.
I invested in an old SD2000 (with mods) that I tried out yesterday....With that and the wife's 2300, we have quite a collection happening here!
I must admit that out of them all, the Vallon is by far my favourite to swing...ergonomically just about perfect ...and I like that you can shove the standard coil in and under shrubs!
Gold will come soon hopefully !!!

Hi Kingswood,
Sounds like you are getting to like the Vallon, hope you score a hit soon.
Mine just arrived into Aus yesterday by DHL, so that's pretty good from UK in under 6 days from purchase..
I'm hoping to pick it up tomorrow but will have to wait til next weekend to try it on the goldfields.
Where I go, there is a lot of under growth so the Vallon and its standard coil is perfect.
I see a lot of folk walking all over this particular place with high end detectors and huge coils swinging the things so fast you'd think they were in a hurry to get home.
The funny thing is, they don't and can't get in and under and probably missing 50% of the area.
You can clearly see the old diggings but it seems too much trouble for them...

Brian

[kingswood]

Hi Kingswood,
Sounds like you are getting to like the Vallon, hope you score a hit soon.
Mine just arrived into Aus yesterday by DHL, so that's pretty good from UK in under 6 days from purchase..
I'm hoping to pick it up tomorrow but will have to wait til next weekend to try it on the goldfields.
Where I go, there is a lot of under growth so the Vallon and its standard coil is perfect.
I see a lot of folk walking all over this particular place with high end detectors and huge coils swinging the things so fast you'd think they were in a hurry to get home.
The funny thing is, they don't and can't get in and under and probably missing 50% of the area.
You can clearly see the old diggings but it seems too much trouble for them...

Brian

Good luck
I was told a story by a very good prospector that the biggest nugget (85 ounces!) he ever found out this way was right under a shrub near its base....I always shove the Vallon in as far as I can

[Mdtoday]

Good luck
I was told a story by a very good prospector that the biggest nugget (85 ounces!) he ever found out this way was right under a shrub near its base....I always shove the Vallon in as far as I can

Well the unit arrived today, packed well, looks well used, even has a funny hand written message for one the operators...

[kingswood]

Well the unit arrived today, packed well, looks well used, even has a funny hand written message for one the operators...

[ATTACH]39738[/ATTACH]

What does the message say????

[Mdtoday]

I gave the Vallon a quick air brush, purchased some batteries, switched it on and followed instructions to adjust sensitivity etc, took it out side and gave it a quick test.
It all works as I thought it would, no problems electronically so that's a great start.
The only thing I'm not certain of, is that the electronics housing seems to be offset or twisted on the shaft, I don't think it is normal.
It looks like you could loosen the bottom housing screws and twist it back to be more central to coil but not sure? see attached pic.

The thing is quite stable even at high sensitivity, yeah it chirps around at the high settings and I don't think you would run it this high all the time BUT.. it appears to be a very stable detector all the same.
I will give it a good clean as per Eric's suggestions and do some investigations on the signals with the scope, just so I know for future reference, what things should look like.
I'm particularly interested to see if the serial data stream is active, what data is sent, what format it is and what handshake (if any) is required.
Not sure how useful it would be but have to have a look. I'll post up findings once done.

So anyway, first impressions, yeah, its a great piece of kit, I'm happy with it but I can see a lot of holes being dug for small junk iron so Ill have to learn to tune into this beast.
Ill take it out to the diggings on the weekend, see if i come home with a sore back or some booty



Brian

[Mdtoday]

What does the message say????

Haha, yeah, the message says " This ones only for the strong, so not for you Turner $$&&$?$$ "

Guess the last word

[Mdtoday]

The thing is quite stable even at high sensitivity, yeah it chirps around at the high settings and I don't think you would run it this high all the time BUT.. it appears to be a very stable detector all the same.

Just to clarify...at high sensitivity settings, when I moved it in normal even height swing motion, the thing was stable. It chirped a bit when I was swinging faster and with a little more up and down motion.

Brian

[Ferric Toes]

I gave the Vallon a quick air brush, purchased some batteries, switched it on and followed instructions to adjust sensitivity etc, took it out side and gave it a quick test.
It all works as I thought it would, no problems electronically so that's a great start.
The only thing I'm not certain of, is that the electronics housing seems to be offset or twisted on the shaft, I don't think it is normal.
It looks like you could loosen the bottom housing screws and twist it back to be more central to coil but not sure? see attached pic.

Hi Brian,
Yes, slacken off the 3 screws under the housing. On some I had to clean out compressed dust from the screw head. The screw at the coil shaft end should have a black plastic key in the gap which engages with a groove in the shaft to stop any relative rotation. I had a unit with this missing which caused the coil to be out of line. Worse still, one had the bottom of the key sheared off by that strong soldier. If the complete key is there then there is sometimes a bit of slack to stop it aligning properly.

What I do is to get a flat level surface and stand the detector on it with the coil at right angles to the shaft and pointing upwards. Put a spirit level across the top of the main case and adjust until level by rotating the body, with the screws just slightly slackened off. When the bubble shows that the box is level, tighten all screws.

Eric.

[Carolina]

Eric: Did you notice the clean spot on the body of Brian's detector body? Also the red lable on the battery tube. Could this be a UXO?