Pinpointer Garrett Pro-Pointer mod improved version

[Henrikras]

The modifired PP was tested today at a grass field by me and some hours by a good Detector freind.
We were both satisfired with the extra sence at a Very hard to dig soil. It was allso Perfect with the speaker in the back..
None Unstable signals.
It safed us some time and not damaging the finds.
henrik.

[Henrikras]

Good work guys and thanx to keep this thread alive and extend it.

What you see above is my second modified Garrett Pro-Pointer, for reserve purposes.

The first one has:
________________

- screw fine tuning
- extracted beeper
- ultrabright red LED instead the white one
- LED switchable to always on
- LED switchable to only on if pressing little button



Your new internal electronic Garrett PP sensitivity gain experiences are welcome, perhaps this way it will become even more powerful.

Not so good - seen under practical view-points - is it if the Garrett is already at highest sensitivity after swich on.
It can result in unwanted detection-signals while "bending" very minimal the ferrite-plastic-region or while poking into the soil.

I made the experience that sometimes it is the best thing if you can reduce the sensitivity manually for just a little bit
while you are exploring the digging-hole. It often also prevents an "everywhere is a little bit too much"-signal situation.

To regulate the sensitivity simply by thumb while holding the pinpointer and exploring the hole is the most easy and effective search-method.

And I found out that around 25-40% (depending on the region) of all finds with the high sensitive Garrett Pro-Pointer are detectable directly without digging
beforewards, just by investigating the grounds surface or pressing the Pinpointer a few cm into it.
Seen over the whole hunting day this gives a pretty faster recovery speed, often the holes to dig are very small or even simple to make with the fingers.


However one of the main issues the Gar. PP has is the usual active beeper! If that pinpointer is at border sensitivity, it is really disturbing if the beeper
goes off like a fire-siren because of every little change in detection field, which also can happen if the tip of the ferrite-rod just gets pressed somehow a little bit.
The vibration only is much better to feel and detect the high sensitivity comfortable.

If there is a way to replace the beeper with a speaker the result should be a very good hearable audio-frequency shift. Because just volume raising could be
a problem in regions with higher background-noise.

And finally:
Perhaps the best results we would get if the coil has at least the double amount of windings as it has now, correctly adjusted to the circuit, of course.
Higher voltage also would be better but that way the (battery) weight and the whole circuit would drive the PP into the area of: "no longer practicable".

And real usage is important. My modded Pro-Pointer meanwhile was in use extremly often, even at rainy days, and it always worked reliable.
btw. you also can use it with a 9V rechargable NiMH accu or with a 7,4v Li-Po battery - there is no sensitivity difference.

Agree Funfinder.

If the Garrett PP is tuned to "much" and gives you not wanted signals, it only to turn it on with a little distance to the object, then you degreased the sens. Garrett shows it a this utube . http://www.youtube.com/watch?v=ZWPD2bRTzsc&sns=em
It a only a matter to learn our tool.
The Rechargeable NiMH isn't so good - to low voltage. The Lipo is 8.4 volt (full) is a little better, but the cut off voltage at the PP is in the 7 volt area, (stabilize voltage is 6.68 inside) that need some extra voltage to work. A good alkaline 9 volt Battery will last long time, Specially If the switch is a hold to turn on switch. That was my choice.
The vibration isn't so easy to feel with gloves. Thats why a combination "Sound and vibration" get my wrote.

Henrik

[Funfinder]

Good work guys and thanx to keep this thread alive and extend it.

What you see above is my second modified Garrett Pro-Pointer, for reserve purposes.

The first one has:
________________

- screw fine tuning
- extracted beeper
- ultrabright red LED instead the white one
- LED switchable to always on
- LED switchable to only on if pressing little button



Your new internal electronic Garrett PP sensitivity gain experiences are welcome, perhaps this way it will become even more powerful.

Not so good - seen under practical view-points - is it if the Garrett is already at highest sensitivity after swich on.
It can result in unwanted detection-signals while "bending" very minimal the ferrite-plastic-region or while poking into the soil.

I made the experience that sometimes it is the best thing if you can reduce the sensitivity manually for just a little bit
while you are exploring the digging-hole. It often also prevents an "everywhere is a little bit too much"-signal situation.

To regulate the sensitivity simply by thumb while holding the pinpointer and exploring the hole is the most easy and effective search-method.

And I found out that around 25-40% (depending on the region) of all finds with the high sensitive Garrett Pro-Pointer are detectable directly without digging
beforewards, just by investigating the grounds surface or pressing the Pinpointer a few cm into it.
Seen over the whole hunting day this gives a pretty faster recovery speed, often the holes to dig are very small or even simple to make with the fingers.


However one of the main issues the Gar. PP has is the usual active beeper! If that pinpointer is at border sensitivity, it is really disturbing if the beeper
goes off like a fire-siren because of every little change in detection field, which also can happen if the tip of the ferrite-rod just gets pressed somehow a little bit.
The vibration only is much better to feel and detect the high sensitivity comfortable.

If there is a way to replace the beeper with a speaker the result should be a very good hearable audio-frequency shift. Because just volume raising could be
a problem in regions with higher background-noise.

And finally:
Perhaps the best results we would get if the coil has at least the double amount of windings as it has now, correctly adjusted to the circuit, of course.
Higher voltage also would be better but that way the (battery) weight and the whole circuit would drive the PP into the area of: "no longer practicable".

And real usage is important. My modded Pro-Pointer meanwhile was in use extremly often, even at rainy days, and it always worked reliable.
btw. you also can use it with a 9V rechargable NiMH accu or with a 7,4v Li-Po battery - there is no sensitivity difference.

[Henrikras]

I'm still Very saticefired with the tuned PP...
Just made a new idea "speaker at the end" - now I dont need to lift the Headphones to hear it.
Need to find or make a protection. the speaker is water resistance and it glued with araldit..
You properly allso noticed that there is allmust never mud at this part of the PP, but in the middle area around the speaker hole and the rubber button, its Allways Muddy and dirty.

Thats three improvement I made. 1. Push switch to turn on. 2. More sens by a offset. 3. Speaker at the end.
Henrik.

[Henrikras]

Did some detecting last Night and had the chance to test the PP.
I Had to turn on/off more often (reset), but it was a Very good help with the increased depth.
The reason to turn it on/off was that it could give small signals just by touching the soil, not a Big problem but to a newbie it could be.
So fare I'm satisfire. A adjustment close to the -5.0 volt could be a good idea (-5.0 gave close to 1 cm extra (4.5 cm at the side)), I did the maximum -6.3 volt (5.0 cm at the side) and that could be to much.
Henrik

[Skippy]

Quote:"One issue with the Garrett PP... it simply not stable enough. Don't know about other brands but the Garrett is like that"
ALL pinpointers have these issues, cheap ones need re-adjustment of a 'tuning' pot often, the Garrett gets round the problem by self-calibrating at every turn-on, but it still drifts after that. And the problem is worse if you are making a high-end sensitive pointer. Unfortunately, when people pay the money that Garretts/Minelab Pro-find's etc sell for, they expect them to be more sensitive AND more stable. Though I DO think that the Garrett could be more stable. And of course you have the rapid drop in 'signal' with target distance, [inverse cube law? I don't know] so large gains in sensitivity result in small distance increases.
The problem with component drift is that it is not simple, or linear. Ceramic capacitors are 'tuned' to 20 degrees C, cooling them or heating them causes a drop in C. And as for the ferrite rod, who knows? there are many variables, we are talking about subtle changes in loss co-efficients. They may be different from one batch of rods to another.

[Henrikras]

Made this Utube to day... Some better that the first one. I'm not worryed this idea wouldn't work to other. I tested and tested, its stable.
still need the temperature test.
utube. http://www.youtube.com/watch?v=nekkZxQxr1g&sns=em

[Henrikras]

The same happens by me a lot of times.. My english could allso be better. Often I must use a translate apps at my IPad.
One issue with the Garrett PP is that you need to turn it on, when you shall use it and not let it stay on one or two minuts... Ist simple not stable enough. Dont know about other brands but the Garrett is like that. Thats allso why I change the on/off swich to a Press and hold botton, it will safe Battery and make it a stable PP.
Just reassembled my PP with the offset tuning and its still working Very nice. Will go out later on a search and try it. This more sens. result I got is some in between the coin/scrue tuning and the Stock sensivity.. I would think that this is a perfect sensivity.
Cold a warm test with different temperature will be next week.
see you.
Henrik.

[Nupi]

Sorry for my bad English. I see that I have not explained to well.
I try now to explain better. My PP works well, but If it is cold and I turn it on, it works well
but if I let him on, he goes in the course of two minutes more sensitive and he begins to give slowly the signal.
If I put it off and on again, he stable. He does this by 10 degrees and lower.For me this is not a problem.
I hope you now understand what I mean.


Off Topic: Now that we have about PP you maybe interested in the thread "Can pinpointer detecting thin chain?" (maybe you already knew)
there is a DIY-PP treated which is more sensitive than the Garrett. With the help from Davor we try to make him very stable
If that succeeds he will be better than the Garrett,
and that for a ridiculous price.
Tak,for your explanation.
nupi

Oh, sorry, I now see that Skippy has clarified. thanks.

[Henrikras]

Time will tell... Skippy.
The margin is getting degreased with a coin at the side, that I'm sure about. But you Maybee right that the reset in a offset its different.

[Skippy]

Quote:"If your Garrett gives you a signal after two minutes in cold weather, you got a broken PP"
I think this is quite normal behaviour, they will easily drift with normal use, often in much less than one minute (obviously if the drift the opposite way, and become less sensitive, you don't notice, because they don't beep that way). Simply placing the pointer on the ground in sunshine will do it, taking it out of your warm pocket into winter cold air will do it, etc.

Quote:"temperature test is easy to do"
Not as easy as you think. The ferrite rod has a drift that will easily be affected by the outside case temperature, for example leave it in the sun for a few seconds, it's black colour will make it get hot and drift quickly. Capacitor drift is more likely affected by the general ambient temp inside the pointer. Any thermal drift caused by circuit components warming up will be localised to that component, so the ferrite rod will not warm up, as it is remote from the oscillator.

Quote:"Garrett made a PP..with a margin. This margin is Big 0.08-0.10 volt. If you tune your PP with a coin on the side, you are working with this margin, and you Press it down to zero. With my idea you decrease this margin down to 0.03-0.05, but you've still got a margin."
I think you've got all mixed up. The "coin on the side" trick has a DIFFERENT effect to that of recalibrating the oscillator amplitude.

[Henrikras]

Great to get some advice. Thanks.
Until I had done some more test, I need to warn about this idea - "reset the PP offset".
1. temperature test is easy to do. That will tell "IF" there is a problem. So fare Nobody knows because this offset tuning is new.
2. NUPI - if your Garrett gives your signal after two minut in cold weather, you got a broken PP or you made some adjustments, or you are handling it wrong. I had NEVER seen or heard of this and our winter is really cold. Turn "off and on" resets your PP.

Garrett made a PP and they wanted to be sure that it will work all over the World in all kind of situation and in all weather. Thats why they made a margin or you could say "a safe area". This margin is Big 0.08-0.10 volt. If you tune your PP with a coin (or a scrue) at the side, you are working with this margin, and you Press it down to zerro. With my idea you decrease this margin down to 0.03-0.05, but you still got a margin. I just dont know how low this margin will go, when the temperature drops.
Next test will be with the PP at different temperature, to see If my margin will be to low in cold weather. It could allso be the opposite situation, that warm weather or high temperature will give problems. Depends how the drift stability is made.
Ill will remove my Utube again until more test is made.
Henrik.

[Nupi]

My Garrett PP drift in cold weather after two minutes and starts the detection signal.
Until the circuit is warming up.

[Skippy]

Some advice here:
The oscillator in the propointer varies with temperature quite a bit. I'm not sure which specific components are mainly to blame, ferrite rods are very likely to be temperature-sensitive, but the caps in the oscillator are ceramic types, not low tempco. Regardless, "tuning" a propointer to the "limit" is a bad idea, a cold day / or a warm day (I forget which way it drifts) could take it over the limit.

[Henrikras]

Hi again....
Okay Ive just been testing this reset in a offset with the PP all over Once more. I even got another Garrett Propointer never open and did the "Henrik tuned PP" vs the standard PP never touch, and I can tell you now, that this idea is perfect..

The Stock PP got excactly this 3.5 cm distance to the silver coin Ive was using in the test at the utube.
I can allso tell you, that you need to find from -5.2 up to -6.4 volt at the measuring point, and If you go over -6.4 / -6.6 volt (like -7.2) it will go in reverse and you lose sens. . You need only to make some try after try with a metal object close to the coil in the PP and do the reset, until you get -5.2 to - 6.4 volt. (Ive found -6.37 volt and it gave me 2 mm more distance).
Remember to remove the metal object after you did the reset, Otherwise you wouldn't get any advantage.
Good luck... It should be Very easy.
Ps. I'm working at a tool to do this reset without taking the PP apart.. If that can be made, it will be like Christmas time.
Henrik.