Vallon VMH3CS Mine Detector

[Myntmaster]

About 3 ohms is normal. And why do you think that the problem is in this part, from the plug to the coil?

[Ferric Toes]

What make of waterproof connectors are you using?

Have you considered a cylindrical housing for the control box? Rectangular housings are very vulnerable to distortion even in shallow water, particularly when made of joined sections. Leaks are likely to develop at joins due to flexing on each immersion. If sea water gets into the Vallon electronics it will almost certainly not be recoverable, even if washed out quickly and dried. The display board with push buttons, although sealed, will stop working at about 2m as the water pressure will depress the switches.

Eric.

[ionut_mtb]

I want to adapt this housing for an underwater detector.

[Ferric Toes]

I want to adapt this housing for an underwater detector.
[ATTACH]49293[/ATTACH]

That should be OK and good for 10m. No guarantees though. Much depends on proper sealing of apertures for external fixtures and control shafts.

One of my first diver held detectors (1970ish) used pvc soil pipe for the body. The pvc end caps I machined on a lathe; bottom plate cemented in and top plate with O rings. Later models used high pressure pvc pipe and were tested to 30m.



Eric.

[Myntmaster]

What make of waterproof connectors are you using?

Have you considered a cylindrical housing for the control box? Rectangular housings are very vulnerable to distortion even in shallow water, particularly when made of joined sections. Leaks are likely to develop at joins due to flexing on each immersion. If sea water gets into the Vallon electronics it will almost certainly not be recoverable, even if washed out quickly and dried. The display board with push buttons, although sealed, will stop working at about 2m as the water pressure will depress the switches.

Eric.

Hi.
I use these connectors
https://www.ebay.com/itm/IP68-Waterp...72.m2749.l2649
I put them on my Garrett Infinium for the season no problem.
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About the case. Yes, for large depths, the square case is very bad.
But for two meters, it's okay. I am not looking at great depths, the whole search takes place up to the neck.
And the detector unit under water is not deeper than a meter. Under the elbow.
Even if the detector falls out of hand, it will be at a depth of 1.60 meters.
Therefore, this method of manufacturing the case in this case is suitable.
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The control and display board will be located in another sealed enclosure. Buttons will be used like these
https://www.ebay.com/itm/3pcs-12v-Wa....c100005.m1851
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The case inside is soldered by partitions.
So that it can withstand pressure a depth of 2 meters.
But if it drowns and deteriorates, I will buy a new one and will do it again.
My English is not very good, if sorry.
Dainis

[Myntmaster]

That should be OK and good for 10m. No guarantees though. Much depends on proper sealing of apertures for external fixtures and control shafts.

One of my first diver held detectors (1970ish) used pvc soil pipe for the body. The pvc end caps I machined on a lathe; bottom plate cemented in and top plate with O rings. Later models used high pressure pvc pipe and were tested to 30m.

[ATTACH]49294[/ATTACH]

Eric.

Great job, what you need for great depths. But I have enough for my 2 meters.
I made the same case for a home-made surfmaster pi. Battery power was separate. Everything works fine.The case is sealed like a tin can.
The only minus if something breaks is to break the case.
Today's trend towards universal detectors will not lead to anything good.
These pseudo-warranties of diving up to 3 meters. How many Equinox, Multi Kruzer ..... drowned? And people do not use anything.

[Myntmaster]

Put the coil and boxes on the detector rod. Fitting.
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[Ferric Toes]

Put the coil and boxes on the detector rod. Fitting.
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That is a very neat job. Hope it performs as good as it looks. Just some labels now . Congratulations!

Eric.

[Myntmaster]

That is a very neat job. Hope it performs as good as it looks. Just some labels now . Congratulations!

Eric.

Thanks.

[Myntmaster]

Hello.
What do you think of the original large coil 60 cm.
Molded plastic case? It looks very fragile.
Or maybe an aluminum pipe, not closed loop.
Aluminum tube for the screen, on large diameters it is easier.
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[bernte_one]

there is no screen
seems more like the typical fiberglass strengthen plastic material, just fragile looking but in real very hard and lasting stuff

[Myntmaster]

Do you think that the winding in the coils of Vallon does not have a screen?
You have accurate information ?
I think the coil without shielding does not work normally on the ground, there will be problems.

[Myntmaster]

Where can I buy a plug as in the photo. Are there any analogs and what kind of connector is the designation.

[Ferric Toes]

Where can I buy a plug as in the photo. Are there any analogs and what kind of connector is the designation.
[ATTACH]49399[/ATTACH]

Type this into eBay 'CIRCULAR INSERT, PIN, 7 WAY MPN: 97-16S-1P AMPHENOL INDUSTRIAL'. This gives a selection of plugs and 7 pin inserts which are correct. However, I think that Vallon had their's specially made to fit and seal inside of their particular collar. I bought one of the blue inserts and it certainly fits the Vallon socket, but you may have to machine your own housing.

On a previous question about shielding, I cut open a dud Vallon standard coil to get a cross section and it is certainly shielded. Opening it up further, the shielding material is identical to Scotch 24 wire mesh tape. It is a fine wire gauge tinned copper tape which is easy to solder a connection wire to. The hard part is winding it on to the coil. All the Vallon compatible coils that I have made use woven nickel plated copper fabric tape with conductive adhesive. Still tedious but much easier. Available on eBay by typing in Search, 'Conductive fabric cloth adhesive tape'. Available in various widths. I wind it helically around the coil overlapping a small amount, with a small gap between start and finish, and with a thin drain wire under the last few turns and then connect to coil ground.

I have reservations regarding a 60cm coil in that the the auto-zeroing of the standard VMH3CS is maybe too fast for that coil, resulting in deep targets zeroing out within the sweep. The largest coil I have made was 38cm which is just about as large as I would want. Vallon did make a reprogrammed version of the VHM3CS which was for detecting larger ordnance more deeply buried. This version has a selection of filters that slow the response down, thereby making the unit respond better on deep targets. Vallon will supply the software in order to do this and the subject has been dealt with in this forum going back maybe a year and a half ago.

Eric.

[Myntmaster]

Hi. I understood you. Thanks for the information.