I want to add a PI coil to my DetectorPro uniprobe headphones. I've heard it make a decent PI unit.

DetectorPro used to sell them but not anymore. They were pricey so I held off buying one hoping that a used one would come up for sale.

I read on a couple of forums that the Garrett Seahunter mark II coils work on the DetectorPro HH PI units, and the coils made for that unit also work on the uniprobe.

My question is on removing the Garrett connector and adding a BNC connetor which is what the uniprobe uses.

Is it as simple as cutting the old connector off and putting a bnc connector on the cable? Should I use one that you have to solder or is the screw on type with some heat shrink tubing ok?

I appreciate any advice on this.

HH
John

I assume youve been to geotech?

IDXMonster Wrote:
-------------------------------------------------------
> I assume youve been to geotech?
I have not. What's geotech?

Hh
John

Geotech1 technical MD forum:
[www.geotech1.com]

Hello John,

I've added a BNC connector to an HH PI coil for a uniprobe, and repaired a couple of probes for friends replacing the bnc connector in their probes. Radio Shack has the same bnc connector, and yes as simple as cutting the cable and resoldering the new connector.

I've never tried a Garrett Seahunter Mark II PI coil on a uniprobe or HH pi, guess it would work proving it's 15us. If the Garrett seahunter is not 15us and let's say 17us or 20us for example, then these coils may work but won't have the sensitivity of a 15us coil and may lack depth.

Just saying, that's from my experience with using different uS pi coils with my 10uS and 15uS Pi's.

Also, you don't need to cut off the Garrett PI connector to see if it works on the uniprobe, you can add jumpers between the two just for experimenting purposes. Then, if if works decent enough you can add the connector later.

HH, Paul

HP Pi coils are built to different specs than a usual Pi.
From my DP Pi coil measurements and some investigation my friend who own a DP Pi and is an electronics engineer we came to the conclusion below.
I was not too thrilled about my DP Pi detector, so I sold it off.

Many coils made will not work with the DP Pi. Mr. Bill did mod a Eric Foster Pi coil to work. You may get a White's TDI coil to work as that PI was an Eric Foster design.


Sven,

It looks like your analysis of the DP PI coil is a good one. It looks like the coil pulse is being coupled to the coil through the 1,000uf capacitor and that is why they are bringing both coil wires up to the circuit board along with the shield. They probably did this so that they did not have to have three power supplies .............. They just use a +9V and a -9V. The large coil inductance (1.9 mh) allows them to couple the coil pulse through the 1,000uf capacitor. This high inductance means that the coil has a low self resonance frequency and is thus a slow coil. Our coils are very fast compared to the DP coil and will not work on it as I found out when I tried my coils on my DP PI. With that much inductance the 22k probably a reasonable value for the dampening resistor. The coil resistance of 11 ohms is very high so the power into the coil will be low and that is understandable since it is designed to work from two 9V batteries. The little 9V radio batteries were only designed to supply 10 to 20 milliamps of continuous current.

Personally, even though it is possible to make a smaller coil for it and you have sniffed out the info that you need, I would not go to the trouble. It will definitely never be able to detect small gold targets as well as our detectors simply because it is designed to operate way to slow. A smaller coil might help a little on smaller rings. When I bought the 11" coil for mine, they told me that it was the best choice for beach hunting and that the 8" coil wouldn't gain much and would reduce my ability to cover the ground. For what it was designed to do it does a good job and would be a good backup detector for water hunting.

DeepTech Vista X with 3 search coils.
Works for me



Edited 1 time(s). Last edit at 01/31/2016 08:42PM by Sven1.

Old California Wrote:
-------------------------------------------------------
> Hello John,
>
> I've added a BNC connector to an HH PI coil for a
> uniprobe, and repaired a couple of probes for
> friends replacing the bnc connector in their
> probes. Radio Shack has the same bnc connector,
> and yes as simple as cutting the cable and
> resoldering the new connector.
>
> I've never tried a Garrett Seahunter Mark II PI
> coil on a uniprobe or HH pi, guess it would work
> proving it's 15us. If the Garrett seahunter is not
> 15us and let's say 17us or 20us for example, then
> these coils may work but won't have the
> sensitivity of a 15us coil and may lack depth.
>
> Just saying, that's from my experience with using
> different uS pi coils with my 10uS and 15uS Pi's.
>
> Also, you don't need to cut off the Garrett PI
> connector to see if it works on the uniprobe, you
> can add jumpers between the two just for
> experimenting purposes. Then, if if works decent
> enough you can add the connector later.
>
> HH, Paul

Thanks Paul.
I'll give that a try. I'm not sure if the Garrett coil is the same at 15us but other have said it works on other forums so it's worth a try.
HH
John

Thanks everyone for your replies.
HH
John

I know the pulse delay of the infinium is adjustable down to 10us and I believe it's the same on the sea hunter mark 2, so I think it will work.
HH
John



Edited 1 time(s). Last edit at 02/01/2016 04:30AM by DirtyJohn.

DirtyJohn Wrote:
-------------------------------------------------------
> I know the pulse delay of the infinium is
> adjustable down to 10us and I believe it's the
> same on the sea hunter mark 2, so I think it will
> work.
> HH
> John


Doesn't matter about Pulse delay, its all in the coil inductance and resistance. And dampening resistors used in the circuitry.
There are other factors involved.
You just can't go and put a 485uh coil on a machine that is set up for a 285uh coil and expect it to work. As many have found out.
Go ahead play and possibly blow out some components...........................
Save your self a visit to the trash can and frustration.
Do your homework, visit Geotech and ask questions, contact Go ask Reg at Findmall [www.findmall.com]

Coil voltage during a pulse spike can surprise you.

Just trying to help...........................

DeepTech Vista X with 3 search coils.
Works for me

Sven1 Wrote:
-------------------------------------------------------
> DirtyJohn Wrote:
> --------------------------------------------------
> -----
> > I know the pulse delay of the infinium is
> > adjustable down to 10us and I believe it's the
> > same on the sea hunter mark 2, so I think it
> will
> > work.
> > HH
> > John
>
>
> Doesn't matter about Pulse delay, its all in the
> coil inductance and resistance. And dampening
> resistors used in the circuitry.
> There are other factors involved.
> You just can't go and put a 485uh coil on a
> machine that is set up for a 285uh coil and expect
> it to work. As many have found out.
> Go ahead play and possibly blow out some
> components...........................
> Save your self a visit to the trash can and
> frustration.
> Do your homework, visit Geotech and ask questions,
> contact Go ask Reg at Findmall
> [www.findmall.com]
>
> Coil voltage during a pulse spike can surprise
> you.
>
> Just trying to help...........................

Thanks for your help. I think I'm a little over my head on this one. I will take your advice.
HH
John

I do have multi meters and an older digital oscilloscope and a signal generator. I can test the probe on the uniprobe and the head set and get the info from that if that will help.

The oscilloscope and the uniprobe and the probe all use BNC connectors so I should be able to plug it in and get some info from that.
John



Edited 2 time(s). Last edit at 02/01/2016 11:25PM by DirtyJohn.

I hadn't thought about it, until what Finphoto mentioned on the other forum.
Call Gary up at DP and ask him.
He'll tell you straight out what will not work.

DeepTech Vista X with 3 search coils.
Works for me