Vallon VMH3CS Mine Detector

[Digger01]

hi guys. chasing a manual for this detector please. Any one have a copy or a link where i can download it?

[jarrett]

Have you not heard of google?
https://www.manualslib.com/manual/14...cs.html#manual

[F117]

Backpack

First of all a sincere "Thank You !" to Mr. Eric Foster for this excellent thread about a magnificent detector.
Now that a lot of these detectors become available on Ebay from tdm_electronics in Poland, I simply couldn't resist and ordered one. I ordered it on Sunday afternoon and it arrived the next Thursday afternoon. Excellent service. The condition of the detector was exactly as described in the pictures: armrest broken ( one rabbit ear broke off ) but - and this is more important: the control panel was intact and without cracks or scratches.
It came with the backpack, earphone, test piece and field card. The ebay seller had also added a printout of the manual in the backpack.
After having cleaned the detector and verified that it worked in both normal and mineral mode, I turned my attention to the backpack. It was very dusty and looked worn (meaning it had seen some action already).
I cleaned it first with water and washing liquid and let it dry.
Next, I started lubricating the zippers with vaseline spray.



The primary usage of this spray is to protect car batteries from moisture. I had bought the can once in an idle attempt to protect a Pickini PCB inside a waterproof housing.
When I accidently sprayed the vaseline onto the canvas next to the zipper, it started looking bright green and shiny again.
I then proceeded to spray the entire backpack. The result was a backpack that looked like new again.



Note: the serial number written on the backpack does not match the serial number of the detector.

[F117]

Batteries

As already described here in detail in this thread: the 3 x D-cell batteries can better be replaced by 2 x 16850 batteries in parallel. Less weight and more capacity ( > 5000 mAh ).
The diameter of the D-cells is 33 mm and the overall length of 3 batteries in series is 183 mm.

1/ Connect the 2 Li-Ion batteries in series:




2/ Wrap them into a sheet of packing foam and cover it with duct tape:




3/ Slide them into a 30 mm diameter drain pipe - length 150 mm


4/ Cut 2 PET bottle necks - this is hard plastic ( not thermo formed ). I used the tops of 2 liter water bottles, but basically any bottle neck will do.




The reason why I thought of bottle necks was because in a previous life, I got carried away by water rockets:
http://users.skynet.be/willaert/bw_wr.htm


5/ Glue the bottle necks on both sides of the drain tube.


6/ Add a washer and screw on outer and inner side of the bottle top: a small one for the positive battery side, with a protruding screw head and larger washers for the negative side with a flat sunken screw head:




7/ Connect the plus and minus leads of the 2 batteries in parallel to the screws of positive and negative bottle top


8/ Screw on the bottle tops - the overall length should be about 180 mm:




9/ Spray paint them in your favorite colors. The result is much better when you have more patience than I do:





10/ Build a matching charger:
I used the battery tube of a 4 x D-cell Maglite torch. It was discarded as it still had the classic bulb lamp instead of newer LEDs. The extra room in the tube houses a small charger PCB and an intermediate bulkhead for the positive terminal of the battery ( that is the ugly screw head you see next to the LED).
I then used the switch hole for the "charging" LED indicator. Power supply is a 7.5V mains adapter. There are also charger units that work with a USB connection:




It may not come unnoticed to the trained eye of a detectorist that the charger stand is part of the Garrett AT armrest that I used to replace the detector armrest with.

[F117]

Typo in step 1:
1/ Connect the 2 Li-Ion batteries in series: ==> should be : Connect the 2 Li Ion batteries in PARALLEL.

[F117]

A question on the VMH3CS batteries:
is it possible to charge the batteries via the 6 pin (Souriau) connector ?
I only found a direct connection between the ground pin and the battery tube chassis (negative terminal).
Is there a connection to the positive battery pole ?

[F117]

Not sure it this report http://www.lu.lv/materiali/bibliotek...%20(STEMD).pdf
has been mentioned here.
It is basically a comparison between 8 different military detectors, including the VMH3CS.
One intriguing sentence:

The Minelab and Vallon VMH3CS detectors (here used with UXO head) have the possibilityof interference cancellation in this context. For the Minelabs, the signal from the “dropped”detector may be treated as any other interference source. The interference cancellation circuiton the “rescue” detector is activated when the detectors approach closely enough to interfere.The VMH3CS detectors synchronise when switched on one after another when in proximity,so that their pulses fall at different times and there is reduced interference. The VMH3 withnormal head, is not fitted with synchronisation.

[F117]

Audio mod

The audio mod to connect a normal low impedance headphone to the 6 pin connector was already described here in detail.
This is the schematic that I implemented:





After cramming all this stuff into a long small plastic housing, the connection with the Souriau 6 pin connector was made with a piece of USB cable. Only 3 connections are needed: Gnd, Signal and "Speaker/Headphone" switch:





Now any "normal" headphone can be connected and attenuated when needed ( the audio is really loud ! ).

[ikaruz]

Hello, i have some questions, i'm thinking to buy this detector, i have a xp deus, i'm thinking between buy a second coil, or buy this detector. is this a deep detector? and someone tryed to find some medieval coins with it? does it worth for some medieval coins? i know its a pi detector, and i need to dig everything, but it will go deep for medieval coins? or they are too small? and if i want to buy a bigger coil for the vallon, where can i find it? thanks

[F117]

Ilkaruz,
I have an XP GoldMaxxPower and also recently bought a Vallon.
If your primary target are coins on farmland, I would definitely go for a bigger coil for the Deus.
The Vallon may have more depth, but on farmland - here on the battelfields of WW1 - this is a nightmare. You will have to dig everything - here, this means a lot of unidentified iron. And some UXO now and again, for which the Vallon was designed primarily.
That is why I only use the XP for field hunting - it discriminates iron ( although the copper ring on an unexploded WW1 grenade gives a good signal... )
I bought the Vallon mainly for beach hunting:
- the beach - especially at low tide - is relatively clean, so every target is worth digging
- the Vallon is not influenced by mineralization - on wet sand - the Deus will be outperformed on wet sand.
Have a look at these guys searching on the beaches with the Vallon: https://www.youtube.com/watch?v=T8pgLQVnwjc
They find a lot of trash on the beach and every now and then a coin.

My 2cts of advice: The Vallon WILL find the coins but if you want to save your back on farmland, go for a bigger Deus coil.

[F117]

Made a detector stand with part of the Garrett AT armcuff stand.
This way, it does not interfere with the travel of the armcuff:

[gravelmonkey]

The audio mod to connect a normal low impedance headphone to the 6 pin connector was already described here in detail.
This is the schematic that I implemented:


[ATTACH]47604[/ATTACH]


After cramming all this stuff into a long small plastic housing, the connection with the Souriau 6 pin connector was made with a piece of USB cable. Only 3 connections are needed: Gnd, Signal and "Speaker/Headphone" switch:


[ATTACH]47605[/ATTACH]


Now any "normal" headphone can be connected and attenuated when needed ( the audio is really loud ! ).

Thank you so much for the info, I've been looking for ages for somethibg like this- I also have a gamma radiation meter with high impedance 'phones I wish to make an adaptor for.

I see two versions of the LT44:

Yellow coloured, Inputs: 20k Ohm, Outputs: 2 @ 1k Ohm

And

Blue coloured "This is the same as the one with the yellow tape but has the more usual blue winding tape and the untapped primary side has a higher d.c. resistance at about 1.08K. If you're looking for low internal resistances to minimise losses, you would prefer the yellow type.".

Can anyone point me in the correct direction?

Would the circuit be fairly universal in its application? (Ie, can I build two and use the second on the radiation meter which currently uses, what I assume, are piezo headphones)?

Thanks!

[F117]

The transformer I used for the VMH3CS mod was the yellow taped one:
https://www.ebay.com/itm/Eagle-LT700...-/120788551407

[F117]

This is a link to the original audio mod done by Eric Foster:
https://www.geotech1.com/forums/show...188#post228188
This is the blue transformer.
I guess both can be used, but I am no expert on audio transformers.
Maybe someone with more knowledge about them can elaborate ...

[F117]

3 hours on the beach with the Vallon.
Normal mode, not mineral.
Wow! It picks up Everything !