Vallon VMH3CS Mine Detector

[Teleno]

Great thread. I have read it with much interest (all 20 pages!!).
I have a VMH3CS on the way and I am interested to see how it goes.
I live in an area of West Australia with lots of hot rocks, so will report back how it handles these.
I must admit that I dont know that much about the workings of detectors, but have gained some knowledge from this thread!!

Plese report!

A short current pulse like the Vallon's reduces the ground response considerably. Targets with shorter time constants (small nuggets) are not affected, so the signal/ground ratio should increase dramatically. For longer time constants the sensitivity wil deteriorate considerably, though.

I'd love to see what your results are.

[kingswood]

Plese report!

A short current pulse like the Vallon's reduces the ground response considerably. Targets with shorter time constants (small nuggets) are not affected, so the signal/ground ratio should increase dramatically. For longer time constants the sensitivity wil deteriorate considerably, though.

I'd love to see what your results are.

I will report back Plan is to bury a few small nuggets in the typical soil/stone areas around here at different depths and see how the Vallon goes. Waiting on delivery, then will test it out.

[kingswood]

One final point ... nowhere in the Vallon brochure does it even mention minimum-metal mines. So this detector may not even be intended for that purpose anyway, and that's why it performs well as a coin detector (see second simulation with target TC of 10us).

For what its worth, in the operational manual they state "The oval search head is recommended for the detection of metal mines and plastic mines with minimum metal content as well as other small metal parts". There is also reference to "plastic mines with minimal metal content" in the equipment list report for the Geneva International Centre for Humanitarian Demining.
The "systematic test and evaultaion of metal detectors (STEMD) report" says "An anomalously high sensitivity value of 250% above reference to maximum sensitivity for the VMH3 in-soil and in-air stands out. The increase of sensitivity for all of the targets for the VMH3 is a phenomenon we cannot explain."....I have read the report but i dont have the technically brains to figure out what its actually saying sorry

[Qiaozhi]

For what its worth, in the operational manual they state "The oval search head is recommended for the detection of metal mines and plastic mines with minimum metal content as well as other small metal parts". There is also reference to "plastic mines with minimal metal content" in the equipment list report for the Geneva International Centre for Humanitarian Demining.
The "systematic test and evaultaion of metal detectors (STEMD) report" says "An anomalously high sensitivity value of 250% above reference to maximum sensitivity for the VMH3 in-soil and in-air stands out. The increase of sensitivity for all of the targets for the VMH3 is a phenomenon we cannot explain."....I have read the report but i dont have the technically brains to figure out what its actually saying sorry

I believe that, after the discovery of the relevant Vallon patent, it became clear that they're actively switching in the damping resistor later in the decay curve, thus allowing the detector to provide early sampling. This would explain why the VMH3 is able to detect low conductivity items while using a relatively high inductance coil.

[Teleno]

I believe that, after the discovery of the relevant Vallon patent, it became clear that they're actively switching in the damping resistor later in the decay curve, thus allowing the detector to provide early sampling. This would explain why the VMH3 is able to detect low conductivity items while using a relatively high inductance coil.

The late damping not only allows for early sampling, it also provides for a half-cosine I(t) at the Tx coil, which has a higher dI/dt at lower levels than the usual exponential damping. dI/dt enhances the short-time constant response.

[KingJL]

A Vallon VMH3CS should be in my grubby little hands by Feb 9!

[Rivers rat]

A Vallon VMH3CS should be in my grubby little hands by Feb 9!

A Vallon a day keep the Surgeon away !!!!!


RR

[Ferric Toes]

Hi Rivers Rat,

Seeing your location is London, are you a Thames river rat? One of my sons wants to do a bit of mud larking and would like to know which detector is best for this. As bits of iron are likely to be a problem in river mud, what detector would you recommend?

Eric.

[Ferric Toes]

A Vallon VMH3CS should be in my grubby little hands by Feb 9!

Even if your hands are clean to start with, they will be coated with Afghan dust on first handling. It is like Talcum powder and can't have done any good for the lungs of the deminer.

Eric.

[Rivers rat]

Hi Eric yes i am there are a few options:

I use mainly f75DST with the small elliptical coil,but i also got a modded Silver sabre 2 with a 4" coil,a Vista gold with a 5.5"coil,a modded lobo with a 5.75 " ,a Deus,a GoldBug with a Nel 5" coil lots of mudlarks use the Laser SCOUT(Compadre) with a 4".The tesoro 4"is the best regarding target separation,put if you hit a cleaner patch with less iron you won't have depth.If he want to contact me i can give him my details by PM

Cheers


RR

[kingswood]

A few on ebay for sale ATM....Cheaper than the one I have already bought .....Might have to grab another one!
I have done a bit more reading about these detectors and I am (almost!) convinced that they will do well in the goldfields....Should have the ability to detect small gold, but also the depth to find nuggets a fair way down. The lack of discrimination may be an issue, but in a reasonably clean area this may not be as much of an issue. I am happy to dig every target....It was the depth of detection I was mainly interested in. The reports say that they are ideal for laterite containing areas, which is my area
I have a friend with a couple of minelab detectors and I am hoping to do some "in the field" comparisons with him.

[Ferric Toes]

A few on ebay for sale ATM....Cheaper than the one I have already bought .....Might have to grab another one!
I have done a bit more reading about these detectors and I am (almost!) convinced that they will do well in the goldfields....Should have the ability to detect small gold, but also the depth to find nuggets a fair way down. The lack of discrimination may be an issue, but in a reasonably clean area this may not be as much of an issue. I am happy to dig every target....It was the depth of detection I was mainly interested in. The reports say that they are ideal for laterite containing areas, which is my area
I have a friend with a couple of minelab detectors and I am hoping to do some "in the field" comparisons with him.

Do you have the full operation manual that gives the full GB set-up rather than the 'quick' compensation by just pressing the C button? I will be very interested to see how it performs in Western Australia where I am told that the mineralisation is not as strong as in the Victoria goldfields that I am familiar with. I have some Victorian ironstone here that it appears to tune out quite nicely, but a fist size lump and a tray of the stuff is rather different to searching on the ground surface.

Eric.

[kingswood]

Do you have the full operation manual that gives the full GB set-up rather than the 'quick' compensation by just pressing the C button? I will be very interested to see how it performs in Western Australia where I am told that the mineralisation is not as strong as in the Victoria goldfields that I am familiar with. I have some Victorian ironstone here that it appears to tune out quite nicely, but a fist size lump and a tray of the stuff is rather different to searching on the ground surface.

Eric.

Hi Mr. Foster. I must thank you for all the very useful info you have given about the Vallon...It has reassured me that I may not be as mad as some of my friends think I am
Yes, I have the full manual......Havent got the detector yet via ebay UK!!
The area that I am in (mid west region of WA) is mineralized, but I can still use my old Garrett VLF so the Vallon should deal with it.
I will report back once I get a chance to try it out.

[Rivers rat]

I can't wait to read a full report on a Beach ,regarding the headphones can you use normal headphones or a mod need to be done????

RR

[kingswood]

Righto...I have read the thread...again....all 21 pages. You guys are way to smart for me !!
I am trying to figure out: what is the Vallon's pulse rate (pulses per second), what is the sample delay time and what is the pulse width?....(someone has been googling how PI detectors work !)
This may have been stated earlier, but my lack of technical knowledge is letting me down!!....