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**Rivers rat** · 10-26-2019, 04:12 PM

Thats a nice haul!!!!

Well done

RR

**Altair** · 10-27-2019, 08:27 PM

While using the VMH3CS into the sea a wave has reach the knurled locking collar of telescopic shaft. Immediately the VMH3CS has detect an error condition, that told me that water is entered on the apparate. Apparently no damage is occured, the detector is back to normal function when I pulled it up from water. Now I have two big problem:
1. what to do to seal the knurled locking collar
2. how to clean and dry the internal part where water is entered: it's sea water and I fear to corrosion!
For point 1., I saw post #1168 from Eric, I will try the proposed tip; for point 2. I don't know how to do!
Any suggestion is well accepted.

**chevesne** · 10-27-2019, 10:12 PM

Rinse with fresh water several times.
That's all.

**juliuss** · 10-28-2019, 03:24 AM

vmc1 error

[CITA = Dutchie; 238393] VMC-1.
?Alguien tiene informaci?n sobre el VMC-1, especialmente si se espera que la electr?nica sea, en general, la misma que la VMH-CS3?

Encontr? este enlace general sobre detectores de minas
https://www.gichd.org/resources/equipment-catalogue/page/4/?tx_displaycontroller%5Bq%5D=&tx_displaycontroller %5Bequipmenttype%5D=1&tx_displaycontroller%5Border ash%5D=&cHH 8c8b881cf661cc76ad645d470b44b679 # .WlNHzrjwmUR [/ QUOTE]

hi, do you have a vallon vmc1 info?

I hope someone can help me with an error of my detector, is a vmc1 but
When I turn it on, it starts and the seconds mark me a led code, which is 2 6 8 10 12 14, check the manual and say it can be an open circuit or the coil, my detector is like new, someone has passed it this?

**Altair** · 10-28-2019, 10:30 AM

Originally posted by chevesne View Post

Rinse with fresh water several times.
That's all.

Thank you chevesne!
Yes, I could rinse with fresh water but then how to dry water that was entered inside?

**kingswood** · 11-05-2019, 07:00 AM

Not a very scientific experiment, but an experiment none the same

Out detecting an area we got quite a bit of gold off. Using the GPZ7000. Its an area with quite salty wash with quartz, some brown clay and below that white clay. The 7000 is noisy in this area.
The Vallon ground balances easily. Test buried an AUD 50 cent. good signal at 6 inches easily. So-so signal at about 8-ish...
I am yet to try it on the salt lake, but will

**gravelmonkey** · 11-08-2019, 04:05 PM

Originally posted by F117 View Post

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 ...

Thanks! I substituted the potentiometers for 1K resistors as that's all I had to hand. I've it loosely wired/taped/balanced together while I source a connector and cable glands. Seems to sound ok, I'll maybe drop the value of the resistors down to make the volume slightly louder.

Your circuit differs from Eric's in that the LT44 secondary and ground are connected differently. I tried both methods but I don't follow how Eric's mod works as pins B and F don't seem to be shorter.

I will attempt to transplant both the original and a second earpieces into a set of headphones- do people recommend wiring these in series of parallel?

I can't for the life of me find the name of the connector, I remember seeing a link to a plastic version but can't find the link again!

**F117** · 11-09-2019, 05:51 PM

Here is a link to a Souriau connector on eBay that fits the connector on the VMH3CS:
https://www.benl.ebay.be/itm/SOURIAU...UAAOxyXzxTIiei

Warning: this is the connector plastic SHELL only. You will have to ask the seller for the appropriate (male) pins !!
I forgot about this, and had to improvise with 3 pins salvaged from another connector.
Not sure what the exact pins are ...

I think these : ? https://benl.rs-online.com/web/p/cir...tacts/0191535/

I used the transformer as 2 individual secondary windings that each drive a single headphone speaker. I think the original circuit from Eric was intended to drive 2 of these speakers in series = headphone with the 2 speakers in series instead of 2 speakers with common ground ?

regards from Belgium,
- Bernard

**TH'r** · 11-10-2019, 06:16 AM

Originally posted by gravelmonkey View Post

Thanks! I substituted the potentiometers for 1K resistors as that's all I had to hand. I've it loosely wired/taped/balanced together while I source a connector and cable glands. Seems to sound ok, I'll maybe drop the value of the resistors down to make the volume slightly louder.

Your circuit differs from Eric's in that the LT44 secondary and ground are connected differently. I tried both methods but I don't follow how Eric's mod works as pins B and F don't seem to be shorter.

I will attempt to transplant both the original and a second earpieces into a set of headphones- do people recommend wiring these in series of parallel?

I can't for the life of me find the name of the connector, I remember seeing a link to a plastic version but can't find the link again!

I used this Mil Spec connector- MS3116F 10-6P. They are usually on E-bay, both new and used, have metal shells, and come with pins and strain relief.

**Denaridigger** · 11-11-2019, 06:30 PM

Originally posted by Ferric Toes View Post

This is a quick solution rather than an elegant one if you want to run standard low impedance phones. The phones shown in the picture are quite cheap, and when switched to stereo they are in series with the ground as common. If you disregard the ground then the series dc resistance is 60 ohms (30R per insert).

What you need then is an LT-44 transformer, available on ebay and connect up as shown in the photo. It is important that the secondary side connects to the tip of the jack plug and the second band only. The third band on the plug (nearest the body) is not used. The phones are readily available (ebay again).

I am planning to use an in-line jack socket, rather than a panel mount, and put the whole thing in a small plastic housing. This arrangement gives adequate volume and which can be turned down with the controls on the phones.

The silver wire you referred to is an outer braid on the twin cable which goes to ground in the detector. This can be cut off where the white and brown wires poke out, as a ground is not needed in this arrangement. Note that the nearest connection on the transformer is not used.

I am working on a wireless headphone setup and tried a Bluetooth transmitter which gave good audio on bluetooth phones, but there is a delay which is unacceptable. The coil has gone past the target by 10-15cm when the signal peaks. Does anyone
know why this happens?[ATTACH]39021[/ATTACH]
[ATTACH]39022[/ATTACH]

I'd be grateful if you could advise how to source the little transparent box the phono plugs into, which is soldered to the LT-44 transformer. The transformer is easily sourced on eBay, but that little box thing.... I'd like to give this arrangement a go with my limited knowledge. Kind regards.

**F117** · 11-11-2019, 07:08 PM

"The little transparent box" = 5 pin 3.5mm stereo socket.
Something like https://www.benl.ebay.be/itm/3-5mm-S...QAAOSwpeBdxNM8
Here, the 5 pin version is an overkill solution:
3 pins = L, R and Gnd are sufficient - and with this particular headphone, only 2 pins = L and R are used : the 2 headphone speakers are connected in series and can be driven between L and R without common ground.
The other 2 pins in this 5 pin version are used to switch the audio signal between "real" speakers and the headphones: when you plug in the male part, you activate a mechanical switch inside the little transparent box.
For the Vallon, a simple 3 pin 3.5 mm socket is OK : L and R to the 2 outer pins of the transformer and Gnd to the middle (common) pin.

**Denaridigger** · 11-11-2019, 08:18 PM

Ahhh right. So a three pin version (one of them a ground) would be this one? Audio Stereo 3.5 Jack socket panel mounting 1pc | eBay

**F117** · 11-12-2019, 06:41 AM

Yes. That should work fine.

**Myntmaster** · 12-07-2019, 09:12 AM

I construct my underwater Vallon

Hello. I am slowly making my detector Vallon.
It will be used under water at sea, we still have a lot of gold jewelry under the sand, still with the whole USSR.
I chose all the electronics. I will install it in a waterproof case. There will be another detector rod. Power supply 7.2 volts 12A lithium.
I will make three more coils of different diameters. I will redo the original and will also use it.