Vallon VMH3CS Mine Detector

[godigit1]

Hi godigit,
what are you connecting your scope to, to measure the above waveforms? I know that if I use a series resistor of 0.1 ohms to measure the current waveform, I get ringing at the beginning and end if I use a wirewound resistor, due to the small inductance it has.
To get a clean waveform, I use a thick film resistor. It is odd that the two waveforms are not identical in shape.

Eric.

Hi Eric,

I was using my probe at 6 inches from edge of the coil.

Today I was finally able to get the cap off the coil and attach the probe directly.
I measured the coil at 1.54 mH and 3.1 ohms but that was attached so not sure about the resistance.
I measured SRF at 1.38 Khz.
It looks like the coil specs are in line with the VMh3 coils.
So should be able to make a smaller coil for it.

Here is the Tx directly attached.




Compared to the Vmh3 the Vmc1 is quite a bit different as far as the Tx ,10 us pulses versus 50 us and 40 us between pulses versus 500
I'm still not sure if the different pulse forms are correct or if there is a problem with the gizmo.
It seems to works very well. have allot more to test and learn but have not found any functionality problems with it yet .
l
If anyone one out there has a Vmc1 and a scope please post the Tx here if you can ?

Thanks Again for all your work and support on the Vmh3.
Be Well

Sorry everyone about my last post I should have re-read it better. I was heading out the door for work.
It should be a (1.2 gram nugget at 6 inches )and (or a young ladies ring).

[godigit1]

Ok I've had time to make it further along in the thread.
I see now i made the same mistake as Phiphi in his first evaluation of the Tx.
Vmhc1 is the same as the Vmh3cs Tx.

I'm too page 26 of this thread so far time is limited but at this point no one is detecting the 1 inch square of foil.

The Vmh1 is not advertised as uxo capable I'm not sure if that is due to coil change ability or of a different processing algorithm maybe?

in the manual for the vmhc1 it says it detects all metals and even mentions gold. it also says it is the first detector specifically for special ops.

First I'm not sure the foil type others have used but with reynolds wrap heavy duty freezer foil the vmc1 hits it at 4 inches with the sensitivity turned down to 10 best I can get in my house..
3/4 by 1 inch it does not detect.

Also have noticed with the Vmc1 that the vibration alert is more reactive on the smallest targets. (Most sensitive.)

Still reading this thread but think I'm going to make a dual field coil to try on the vallon.
Has anyone tried that Yet on a vallon?

[green]

Hi godigit
Regular strength aluminum foil TC is about .07us/mm for a square. HD is about .1us/mm for a square. Width pretty much controls the TC, best to keep test piece square since length has some effect.

[godigit1]

Hi Green,
Thanks for your response.

I picked up some regular foil and made new test pieces.
I cut in 1/16 increments from 7/8 to 1and1/16.
tested on both the Tdi pro with a Jimmy 5x10" folded mono and gizmo stock coil.

Gizmo sen's 8 normal mode.
A. 7/8x7/8 = 0"
B. 15/16 = 1"
C.1" = 1 .5"
D.1 1/16" = 2"
Tdi Sen's 4.5 Gb Off delay 10us
A. 2.5" min us detectable at 1/2 inch= 14us
B. 3" = 16.5us
C. 4.5" =18 us
D. 5.5" =20 us

The Gizmo does not do too shabby very capable of micro jewelry on the beach(Sub Gram) .
That's what it takes for me to want to use a machine on the beach as most of the gold finds I get are in the gram range.

[trance]

I have a vallon but cannot for the life of me work out how to change the channel to make it more stable. can someone explain it to me or post me a copy of the full manual? The manual I have doesnt mention how to change the channels I have the 2010 model.
Thanks everyone

[godigit1]

Hi Trance,

Somewhere here is a link to the vmh3 Manual I think .

But if you have a 2010 model it may have the software update and I think its the same method as the gizmo.
Here is the gizmo manual.
page 39 and 40.
https://dl-manual.com/doc/vallon-vmc1-manual-no49yy016gz9

[trance]

Hi Trance,

Somewhere here is a link to the vmh3 Manual I think .

But if you have a 2010 model it may have the software update and I think its the same method as the gizmo.
Here is the gizmo manual.
page 39 and 40.
https://dl-manual.com/doc/vallon-vmc1-manual-no49yy016gz9

Thank you very much. I will have a look

[kingswood]

I have a vallon but cannot for the life of me work out how to change the channel to make it more stable. can someone explain it to me or post me a copy of the full manual? The manual I have doesnt mention how to change the channels I have the 2010 model.
Thanks everyone

I think its this

[kingswood]

One thing you could try regarding the EMI on one of the Vallons is to check the channel settings to see if they are different.
On the one that is less affected by EMI set the mode selector to the speaker symbol. Press C and keep it pressed. After 3 seconds you get a short beep, but keep pressing C. Two LEDs should eventually light, 12 being one of them, but ignore this one. Note the LED number of the other one.

Switch off the first detector and go to the noisy one and repeat the process. If it settles at a different LED number, press either the + or - button so that the channel LED number is the same as te first detector. Switch back to the normal mode and see if the EMI is any better. Any channel change is stored on switch off, so on further use it will be the last change that you are working with.

If there is no improvement in EMI, then there could be a difference in the firmware settings of the two.

EMI is a problem for me in, or near, my workshop. No change in channel setting will cure it and I have not yet found out what the source is. Whatever causes it, goes off after 5.30pm and then the Vallons are quiet. It must come from an adjacent shop; maybe my wife's. I can hear it quite loudly on a medium wave radio and during the day it blots out all but the strongest stations. I use a 14in search coil as a loop antenna, so it is definitely the EM noise that plays havoc with the detectors. I'll have to find a portable radio with ferrite antenna and do some direction finding.

Eric.

Bump of Eric's advice on Channel selection

[TH'r]

I have a vallon but cannot for the life of me work out how to change the channel to make it more stable. can someone explain it to me or post me a copy of the full manual? The manual I have doesnt mention how to change the channels I have the 2010 model.
Thanks everyone

Look at Eric's post #1186 to change channels.

[kingswood]

My 10 minute agricultural nothing fancy audio fix
used a broken adapter cable I had from the sdc2300. Attached white and brown wires. Plugged into my booster via cable, its very loud thru dual detecting speakers!!! Used normal tape as was experimenting. Will solder and use electrical tape later. It works...loudly! Will try with normal headphones at some point. I dont generally use headphones when detecting anyway, so dual speakers would work for me. I am scared of wild dogs attacking me and would rather hear them before they jump on my back

[surfdetector]

Hi Trance,

Somewhere here is a link to the vmh3 Manual I think .

But if you have a 2010 model it may have the software update and I think its the same method as the gizmo.
Here is the gizmo manual.
page 39 and 40.
https://dl-manual.com/doc/vallon-vmc1-manual-no49yy016gz9

Thank you for the Gizmo manual. I just received my machine today and am looking forward to learning it.
Cheers

[godigit1]

Thank you for the Gizmo manual. I just received my machine today and am looking forward to learning it.
Cheers

Hi Surfdetector,

" Nice" hope its all in good shape for you !
Curious Did you get a Gizmo or the VMH3cs?

Gizmo is put together a bit different I have some tear down shots if you got a gizmo and need them.

[surfdetector]

Hi Surfdetector,

" Nice" hope its all in good shape for you !
Curious Did you get a Gizmo or the VMH3cs?

Gizmo is put together a bit different I have some tear down shots if you got a gizmo and need them.

I got the Gizmo. It appears to be in great shape. I need to find some time this weekend to learn it a bit. Any info you have would be great. Thanks.

[godigit1]

Cool glad it is all good.
I hear you I've been pretty strapped for time as well.

Mine was bare no headphones arm rest and the wrong battery cap.

I'm still trying to get to know mine as well.
I've hunted it three times next to a tdi and its pretty competitive but the TDI does trump it for very small items.

Battery life is really bad, it says 8 hours feels more like 6 three hunts three sets of C's

So I repackaged it.



my battery is a bit over kill and at the moment is waist mount eventually will be under arm cuff.
The whole mod with a 1and a 1/2 pound power supply is 5.5 pounds.
used a go pro case to make it water prof. 10 amp battery eliminator and battery monitor both fit in the case.

Just finished my first coil for it came up a little short at 1186 uh and 1.68 ohms but the gizmo accepts it so seems there some room to work with.
for kicks tried a 300 uh coil , no go would be nice to know where the cut off is both for l and R.

as I find out more Ill post and would be interested in your experiences as well.

Have Fun