Vallon VMH3CS Mine Detector

[Dutchie]

A few pages earlier the discussion was about separation Tx and Rx in order to be able to have digital signal processing/analysis.

Would it be an option to have a larger coil connected to the Vallon and a smaller diameter coil inside the same housing (well shielded from the Tx) and process the signal from the extra Rx any way you would like or
pickup the signal by having a tiny coil around the central lead from the Vallon coil to the Vallon PI(I expect a very very small signal there?) and bring it out for processing

[Ferric Toes]

I've found the cause of Justin's problem with the control panel. If you look carefully at the picture in post 1346, you can see a green tinge on the edges of the - and C switch mechanisms. Removing the other layers so that the switch actuators can be removed, exposed the following.



I had previously noticed that the top label had lifted a bit along the left hand edge and I would guess that water got in and caused corrosion of the spring steel top contacts. Only the underside is gold plated but the corrosion has crept there too. The contact with the brown dots should be for the middle C switch and that was completely inactive as you might guess. The - switch worked now and again if you pushed hard. The board should clean up OK and I could use it on one of my variations that use external push buttons or toggle switches.

Eric.

[Ferric Toes]

I'll PM you on that.

Eric.

[Dutchie]

Thanks!

This looks great.
The hard part will be to carefully cut out the form and get the holes on the right place.

[Ferric Toes]

Hi Eric,

The leds are OK including number 9. The leds are actually above the numbers and the hole is exactly through the number.
Further I seem to have a contact problem with the batteries in the housing which is apparent only when the batteries have been removed and thereafter placed back again. Will check that one out myself..

In your picture is do not see any fabric or cloth. Hope the hole was not caused by shrapnell...

Karel

Karel

Hi Karel,
There is no fabric or cloth in the display panel. The pictures show how a hole can be fixed with label laminating film. The film is a matt one, but as you can see, the numbers show clearly through it as do the LEDs when they are lit.The top label I used is very scratched and the scratches show through as well.
First I cleaned the area where the film will be stuck with methylated spirit. I then drew the profile I wanted on the backing paper, then cut out with sharp scissors or scalpel. The push switches must be clear of the film, particularly the C switch. Peel back the paper a little way on one corner and cut the paper off as shown. This allows you to align the laminate easily. When it is correct press down that corner with the exposed adhesive. With the laminate anchored, progressivel peel back the remaining paper, smoothing down on the top label as you go.
You should end up as the second picture which was angled to the light so that it could be clearly seen. The third picture shows how the eye would see it, as barely perceptible.

Eric.

[Dutchie]

Hi Eric,

The leds are OK including number 9. The leds are actually above the numbers and the hole is exactly through the number.
Further I seem to have a contact problem with the batteries in the housing which is apparent only when the batteries have been removed and thereafter placed back again. Will check that one out myself..

In your picture is do not see any fabric or cloth. Hope the hole was not caused by shrapnell...

Karel

Karel

[tifred]

hi thomas ,
no the coil minelab explorer does not work on the Vallon!
I used the minelab coil, removed the original winding and put a new winding, following the advice of eric foster.

[Ferric Toes]

Dear Jaypay, dear Altair, dear Eric,
Thanks for your replies.
It looks like the hole is through. It is some 2 mm round over led no 9. Something like cloth seems to be on it - I tried to remove a bit carefully (Do you know what is directly under this plastic front).
Will epoxy hold on carbonate or is the risk to cement the whole carbonate shield to the board below?..
For now I will send Eric a pm.

Hi Dutchie,
Here is a picture of the panel with the top layer removed. Underneath is another layer which covers the LEDs also. Below this second layer are two other layers, but have a full arced cutout for the LED's and don't provide further protection. These last two layers are to hold the switch parts in place.

Presumably your no.9 LED is still functioning? I had one unit where the puncture had gone through and broken the LED. I wasn't bothered as I bought a few units very cheap just for spares as they were otherwise unsellable.

The one I am dissecting in the picture is from Justin's machine where I am trying to find the fault that prevents the buttons working properly. I don't fancy my chances though as it is all microcircuitry with a programmable chip. The board has been replaced in Justin's unit and it's on its way back.

I will check tomorrow how well my polycarbonate adhesive film sticks to the top layer.

Eric.

[Dutchie]

Thanks,

after some more cleaning my serial no seems to be 2396 and not 239E - first digit still not very readable.
for the number of the set on the pelli case if have to add rhe last digit so that seems to be the same as yours (probably more a type number than a serial number...)

just for reference mine is 2010, serial 13839, NSN 138-5998-602-386

[6666]

just for reference mine is 2010, serial 13839, NSN 138-5998-602-386

[Dutchie]

More info about my Vallon seral no etc.

My Vallon VMH3CS is British - automatic channel selection is not available.

it is manufactured in 2007 so it maybe an early one.
The serial no for the kit (on the peli case) is NSN 1385-99-860-238
The serial no for the detector is 239E but the first number is fast unreadable - it may be a zero or an one as well...

Wonder if anyone else has a 2007 version en what the serial is.. and anyone in the Netherlands or nearby.

Karel (Dutchie)

[6666]

hello 6666
I do not use a headphone jack, it is connected directly to the chassis

thank you for reply, i thought you may have found a plug that fits the normal headphone jack, but it appears you have replaced the jack and connect direct to the chassis, cheers.

[Dutchie]

Does the hole go right through? I have a couple which look as though they have be struck with a pointed object, but it hasn't penetrated right through. The top layer appears to be a tough polycarbonate that would not be easily penetrated.

Eric.

Dear Jaypay, dear Altair, dear Eric,
Thanks for your replies.
It looks like the hole is through. It is some 2 mm round over led no 9. Something like cloth seems to be on it - I tried to remove a bit carefully (Do you know what is directly under this plastic front).
Will epoxy hold on carbonate or is the risk to cement the whole carbonate shield to the board below?..
For now I will send Eric a pm.

[Ferric Toes]

Good day everyone.
Today I can finally join the group of Vallon owners. This is my first metal detector!

The display window has a small hole over one of the leds. I do not know yet what is best to do : fill the hole with a clear epoxy or something or try and make a new window from perspex. Any suggestions are welcome
For extensive modifications I will wait a while.
First I will download the manual and read it a few times until I fully understand it.

Karel (Dutchie)

Does the hole go right through? I have a couple which look as though they have be struck with a pointed object, but it hasn't penetrated right through. The top layer appears to be a tough polycarbonate that would not be easily penetrated. If there was any doubt, I would use a shaped piece of transparent polycarbonate film with and adhesive backing and stick it over the existing window. This material is used in DIY label making. I can post a piece out to you if you PM an address.

Eric.

[Ferric Toes]

Karel, it happened first time to me too! Jaypay is right! You must well tight the battery cover.

Hi Karel and Altair,
With the Vallons I have had it was hard to tell when the battery cover was making contact with the tube end because the O ring was dry and dusty. The remedy is to smear some silicon grease on the O ring and the taper in the plastic battery cover that the O ring mates with. Now it is easy to feel the solid contact when it is fully mated.

Eric.