How can I increase power to coil on Paranah PI

[Frank-S]

I have a modified paranah pi,question for anyone who might know.I am trying to increase power to coil.
stock paranah will detect a nickel at 6" with 8"coil,I made a 7" coil it will detect a nickel at 10" with same
restance as stock coil,I made a 15" coil same restance it only detectd a nickel at 14"I dont think its
getting enouth power to 15" coil.
question- has anyone tryed putting a step up transfomer between coil and controal box,maybe a 2 to 1
some-thing like 50 turns primary 100 turns secondary.
Thanks Frank -S

 

[Reg]

Frank,

What you are getting is well within the range of what you should get with a larger coil the size you mentioned.

BTW, I don't recommend you try increasing the power of a PI using a transformer. You might raise the voltage to the Transmit circuitry but I doubt you will see much of an improvement and it could become a nightmare to do.

I have attached a chart Eric posted many years ago that gives a relative indication one might expect if they used a larger coil.

To use the chart, draw a vertical line from the 7" diameter on the horizontal scale. Draw this to the 10" on the vertical scale.

In this case, your 7" vertical line peaks between two arc's, with one having the arrow above it. So, you have to interpolate a new arc between the one with the arrow and the one above it. Since you are about half way between the two arc's, then you will be about half way between the two arcs at the 15" zone.

Now, draw a vertical line from the 15" mark on the horizontal scale. Draw it up to the halfway point between the two arc's mentioned and you get the approximate distance you should be able to detect the nickel. In this case, the calculated distance is about 13.5". So, you are doing a little better.

I have modified another copy of the chart chart to show what I am talking about.

Reg

 

[Frank-S]

Thanks Reg.
Years ago when you helped me modify CS-6, we got to detect a nickel at 15''.
There has to be a way to get a fue more inches larger than coil size.the paranah
has no 555 ic,if I can find a way to speed it up more,may-be.
Frank

 

[Reg]

Frank,

You are not going to get much more depth out of the detector than you are getting now. Now, with that said, I suspect the PI you are using has a delay greater than 15 usec and probably closer to 20 usec. If this is the case, you might gain a little by increasing the inductance of the coil. In simple terms, try more turns in the coil. The old CS 6 had a 1mh coil. I doubt the Piranha has anything near that. So, you might wind another coil with a few more turns than you are using now. I would try 25 turns first if it is more turns than the one you built to see if all works ok. If it does, then go up to as high as 30 turns and see how that works. Hopefully, you will be able to reach the distance you used to get on the CS 6.

Reg

 

[Frank-S]

Reg.
I have allready did that I started at 27 turns and stoped at 22 turns on 15" coil.
I have no way of checking usec, I use dital ohm meter.all my paranah coils work
bets from 5.4 to 5.8 ohms.I am expermenting with 2 coils in one on a 6".it detect a small
nuget at 3and1/4"nickel 10"dont know weight of nuget,I live in FL most beach and treasure hunting.
Had one of Garret first Inf-PI detectors it would only detect same nuget right at. coil .
I am thinking about getting one of White new PI.will it detect a coin deper than size of coil.
also does it have electronic in coil.
Frank.

 

[Reg]

Frank,

Most PI's price in the same price range won't do that much better under ideal conditions than what you are experiencing now. I expect the White's will do a little better but don't expect that much difference. However, a simple feature like a frequency control can make a big difference under the right conditions since quite often external EMI (electronic noise) will often be what limits the depth in an area as much as anything.

So, in some cases, the features of a particular detector make all the difference. Things like an adjustable delay may allow a detector to detect small gold better than another, but do little when it comes to enhancing signals from coins, except maybe to allow the operator to adjust the delay far enough out to eliminate foil or even the ground signal.

Now, with what I said, I expect there will be discussions forthcoming on how great a detector does, depth wise. This is common. Unfortunately, depth is relative and unpredictable. More importantly, a single example is of little value. It is what is the norm day after day that is what is real and important.

Reg

 

[6666]

Hi Reg
can I ask another question please ?

Given a typical PI timing deseign as attached
and also given that the Tx pps and the TX pusle width is varible (A),
and also the delay (C) to the first sample is varible.

With respect to PI timing for best detection of small gold rings at the beach
in your experiments have you found a sweet spot for the two sample widths (B&E)
and the time between the 2 samples (D).
thanks
6666

 

[Reg]

Quad 6,

I am not sure exactly what you are asking but I will give it a shot at answering what I think you are requesting.

Now, as a general rule, the shorter the delay, the greater the signal to small gold, including small gold rings. Unfortunately, getting below 10 usec is extremely tough so it is generally the minimum delay on many top end PI's. Also, when searching for small gold rings, the pulse length doesn't need to be that long.

As for when the second sample should be taken, well, the main object of the second sample is to eliminate the earth field effect and reduce low frequency noise, so any timing distance greater than that at which the primary target signal is minimal so it not cause any significant target signal loss will work fine. In simple terms, on small gold rings, most target response is gone by 60 to 80 usec. So, any distance greater than this should work fine. If you are designing this detector, then you might want to verify just when the primary target response is minimal. This is simple to do. Simply make the main sample delay variable out to something like 100 usec and check the target response as you advance the delay that far.

BTW, the Goldquest by Eric Foster ran at a 10Khz rate and it is well known for finding small gold rings. This meant that all signals had to happen in 100 usec. With a delay of 10 used then 30 usec for the transmit pulse, then another 10 usec delay before the first 10 usec sample, it didn't leave much time for the next sample. Since the last sample was also 10 usec, then the total distance between the two samples was 40 usec if my math is correct.

Personally, I feel the minimal timing distance between the two samples can even be less and not affect the depth much at all.

One of the reasons for having a frequency control is to adjust the timing variables, one of which is the sample timing including the time between the two samples. Ideally, being able to adjust the frequency and then adjust the secondary sample timing would probably give a little more help with some noise.

So, to answer your question about a sweet spot between the timing between the two samples is going to be a variable and dependent upon the local EMI noise. In other words, I don't think anyone will find a single timing distance between the two samples that works the best everywhere.

I am assuming you are also referring to a simple straight PI with no ground balance, because such a device further complicates this timing issue.

Reg

 

[6666]

Hi Reg
thanks for reply
sorry if my question was a bit cryptic
you did a good job of figureing out what I was trying to ask.

Yes its just your basic PI circuit with no ground balance.
6666

 

[Frank-S]

Thanks Reg,
one last question White TDI PI does it have electronic circuit
in the coil.I live in FL the beaches here are re-nurshed with sand
I need a detectod will detect a coin 18'' to about 25".
Thanks again for your help.
Frank.

 

[Reg]

Frank,

The TDI doesn't have any electronics in the coil. Unfortunately, the coin depths you are looking for are not anything I would expect you to get on a regular basis with the TDI either. Now, if you buy the right fisherman's ruler, who knows what depths you can get.

Reg

 

[emma99]

Hi...
i think tested and developed to produce the highest spark possible. The new Piranha X ignition coil far outperforms stock and competitors coils...

 

[Eric Foster]

It's only $49.99 too, and the shielding is second to none. At that price why not get one and let us know how you get on. The results may shock you.

Eric.

 

[Frank-S]

How big is the Piranah X ignition coil,$49.99 not bad price.
where can you get one.in US.
Frank-s

 

[Sven]

Haven't figured out how to hook it up to my PI yet.


"20-30% power increase over stock coil Includes Piranha X coil, Piranha X wire, NGK Plug Cap. Fits Kawasaki KLX110, DRZ110, DRZ70, Honda CRF50, XR50, Z50, Trail 70, Dax, Monkey bikes, CRF70, XR50, And all other Pit Bikes. Great Performance upgrade for ATC70 & TRX90 ATV's too.
NOTE: This coil works with the newer Stator / CDI systems. It does NOT work with points and condensers"

I think I will see if it will work with my Kawasaki Z1000 or Honda DT125 metal detectors.............

Spammers have recently infiltrated the Findmall Forums.

 

[Frank-S]

The piranha X coil looks like no more than a ignition coil for a internal combustion engine.
a transformer, I use to experment with super auto coils to attract fine gold.
Do you know if the piranha X coil will work on a PI metal detector.
If a person steps out in the snow he will get snowed on.