Vallon VMH3CS Mine Detector

[Ferric Toes]

This will help. The grey wire goes to three terminals that are linked together on the switch.

I had the same problem myself with one Vallon that had the same knob and knob shroud. However, I bought it cheap as a 'not working' unit and when I fixed the wires it worked fine. Getting the nut off the switch was a big struggle but a drop of WD40 left on the thread for a while seemed to loosen it up. There are supposed to be flats on the hole in the box to stop the switch rotating and also the original escutcheon that ran between the 6 pin connector and the selector switch also had flats in the hole and a much better fixing nut that protruded further.

Having fixed the wires I did have a problem tightening the nut enough to stop it rotating again. It really needs a locking washer behind the panel instead of the rubber seal. OK as long as you are not planning to take the control box into water.

Relocating the switch is a test of patience. I poked it around with a wooden stick until the shaft dropped into the hole.

Eric.

[chevesne]

Edit.
Selector is down.

[chevesne]

Hello everyone,
@ Eric:
Admired reader of all the modifications that you have made to the Vallon, I am on your tracks to make this MD lighter.
I encountered a problem, the selector was turning without unscrewing.
The wires have broken.
I am now looking for the connections of the wires:
Brown
Grey
White brown
White gray
Depending on the position of the selector:
off
Normal
Mineral
HP

And I do not see how to put down this contactor.


I hope you will answer me, but already thank you for reading me.

[chirosi]

Si: TDI Electronics, Poland have sold me two VALLONS and back packs at reasonable prices. I see one listed now with broken arm rest and they are asking for an offer. $100 US should buy it. Well, watch their adds and always make an low offer. My first purchase came with rabbit ear arm cuff but the add showed the newer two piece. I complained and got $100 US return. Good people.

Carolina

Thank you... I will check that seller out

Si

[Ferric Toes]

Hi Chirosi

See PM

Eric.

[Carolina]

Si: TDI Electronics, Poland have sold me two VALLONS and back packs at reasonable prices. I see one listed now with broken arm rest and they are asking for an offer. $100 US should buy it. Well, watch their adds and always make an low offer. My first purchase came with rabbit ear arm cuff but the add showed the newer two piece. I complained and got $100 US return. Good people.

Carolina

[chirosi]

Hi Eric,

Thank you for taking the time to reply and thank you for all your hard work with this machine and all your help on the thread here.

The first machine has been returned and the second machine is going back on Monday. So.... 1. Yes, only one machine switched on at a time 2. Yes phone was switched off when testing outside. 3. unable to try that as first machine returned 4. The connectors appeared undamaged and I did clean them out.

I am totally baffled. Both machines were tried in many different locations where no EMI should of been present and both appeared to have the same problem. The problem seemed to appear mainly when swinging the detector as you would normally when detecting. It felt to me like it was making a bad connection when doing this, causing the machine to spike and give off false signals. Could the machines have a shielding issue that only shows up when moving the unit and be fine when stationary to run through the start up test sequence? Adjusting the sensitivity and using normal or mineral mode did not make it any better. All I know for sure was that both were totally unusable in that state, hence the returns.

I'm not sure what to do now as I really fancied one of these and have been reading up about them here for a while now. I may order another but my confidence with them now has worn thin

Thanks, Si

[Ferric Toes]

Hi,
I'm new here but have been following this thread with interest as I have purchased two of these detectors now from different sellers on ebay. Unfortunately both seem to have the same fault which seems a little odd.
Both machines are dated 2010 and both have broken seals. When switching the units on they both start up correctly and run through the start up sequence fine but then refuse to settle and throw off random ghost signals when swinging the detector. I have tried changing the frequencies as detailed in this thread and also tried in normal and mineral mode with ground balancing and without. I have also tried testing it in different locations that should be a long way away from any EMI, none of which helps. Movement of the detectors seems to be causing the ghosting.
Has anyone any ideas please as to what the problem might be. Am I doing something wrong or have I just been very unlucky? as I find it strange that I have managed to get two different machines from different sources both exhibiting the same problem.

Thanks, Si

Hi Si,

You don't appear to be doing anything wrong, but the fact that two machines have the same problem is very strange. Out of about 20 units that I have worked on, some of which were very bad cosmetically, only one had an electonics that has a fault. If it fires up and goes through the start sequence, then it is working correctly. Sometimes a key pad is stuck but that doesn't affect the default operation.

Some basic questions 1. Do you have only one machine switched on at a time? 2. Is you mobile phone switched off? 3. Have you swapped coils from one machine to the other? Do the contacts (male and female) on the 7 pin shaft connector appear undamaged? I always clean out any dust and apply a drop of contact cleaner/lubricant to them.

Eric.

[chirosi]

Hi,
I'm new here but have been following this thread with interest as I have purchased two of these detectors now from different sellers on ebay. Unfortunately both seem to have the same fault which seems a little odd.
Both machines are dated 2010 and both have broken seals. When switching the units on they both start up correctly and run through the start up sequence fine but then refuse to settle and throw off random ghost signals when swinging the detector. I have tried changing the frequencies as detailed in this thread and also tried in normal and mineral mode with ground balancing and without. I have also tried testing it in different locations that should be a long way away from any EMI, none of which helps. Movement of the detectors seems to be causing the ghosting.
Has anyone any ideas please as to what the problem might be. Am I doing something wrong or have I just been very unlucky? as I find it strange that I have managed to get two different machines from different sources both exhibiting the same problem.

Thanks, Si

[Ferric Toes]

Problem sloved do you have some tips for a good connector?

Hi Stefan,
The problem is that you don't have much room. What I would do is put a coil connector in place of the 6 pin and route the audio for phones to the back end via the black tube. For standard phones you will need a step down transformer. The only thing you need from the 6 pin is the audio as the RS232 connections are for programming and I doubt you will be doing any of that.

It may be that part of the problem is the close proximity of the audio, which is probably a 10V pulse waveform, which is very close to a sensitive receiver loop where the coax splits in the connector. This could give you a feedback effect which makes the detector unstable.

I will think about it and get back to you.

Eric.

[stefan-s]

Problem sloved do you have some tips for a good connector?

[stefan-s]

Looks good eric

[Mdtoday]

Great work Eric, that's a nice looking bit of kit!

Brian

[Carolina]

Well sir, that didn't take long!!! Will show Clay. I like it!

Carolina

[Ferric Toes]

The Bridport Beast

This is the ultimate predator. I have added a Garrett Z link, a push button by the hand grip and perfect balance. The Z Link works great with no noticeable delay and good tone. The C button on the handle is for quick compensation and has all sorts of functions in combination with other switch and button settings.

Eric.