Hammerhead Rev D project newbie help

[scott-bc]

I have been reading alot of the postings on this project and it looks very interesting. Seems like it has gone through some major trial to come up to a good system being Rev D. I am new to this forum and electronics is my part experience so this gets m excited. I could read all the post but in turn would confuse more than ever. Sor far I understand we buy the board from Carl and we source out our components. This is easy to do.

Once we have the components in this is where i get asking the questions:

1. I would like to buy a market PI coil, what is the best to use? I seem to read alot about single coil and DD coils. What gives the best depth?

2. Rev D board - what is the best aftermarket coil to use? I see Coiltek allot. Also depending on the coil I use I might need to revise some of the components?

3. once it is powered up what instructions do I need to adjust all the pots to get the correct voltage ouputs and where do I test??

4. Does this HH system get better results than say a Whites, garret etc PI unit? I think for the HH price I can't go wrong.

Basically I am looking for some tips in building this PI detector.

Thanks.

Scott

[Qiaozhi]

I have been reading alot of the postings on this project and it looks very interesting. Seems like it has gone through some major trial to come up to a good system being Rev D. I am new to this forum and electronics is my part experience so this gets m excited. I could read all the post but in turn would confuse more than ever. Sor far I understand we buy the board from Carl and we source out our components. This is easy to do.

Once we have the components in this is where i get asking the questions:

1. I would like to buy a market PI coil, what is the best to use? I seem to read alot about single coil and DD coils. What gives the best depth?

2. Rev D board - what is the best aftermarket coil to use? I see Coiltek allot. Also depending on the coil I use I might need to revise some of the components?

3. once it is powered up what instructions do I need to adjust all the pots to get the correct voltage ouputs and where do I test??

4. Does this HH system get better results than say a Whites, garret etc PI unit? I think for the HH price I can't go wrong.

Basically I am looking for some tips in building this PI detector.

Thanks.

Scott

Hi Scott,

You should start by looking here -> http://geotech.thunting.com/cgi-bin/...head/index.dat
There's no need to trawl through hundreds of postings.

[Carl-NC]

1. I would like to buy a market PI coil, what is the best to use? I seem to read alot about single coil and DD coils. What gives the best depth?

On a std PI design (like HH), I suspect the DD might have an edge, though I don't know that for a fact.

2. Rev D board - what is the best aftermarket coil to use? I see Coiltek allot. Also depending on the coil I use I might need to revise some of the components?

Don't know the best... yes, you will need to adjust the damping R.

3. once it is powered up what instructions do I need to adjust all the pots to get the correct voltage ouputs and where do I test??

See the article.

4. Does this HH system get better results than say a Whites, garret etc PI unit? I think for the HH price I can't go wrong.

Potentially the same, if adjusted correctly.

- Carl

[Reg]

Hi Scott,

You certainly have asked a lot of questions, many of which can't be answered yet.

What do you plan on hunting with the Hammerhead (HH) PI? That can make somewhat of a difference.

Now, as for buying a coil, I would recommend a Minelab (ML) compatible coil such as one made by Nugget Finder or Coiltek. A ML made coil can be used also. I would also recommend the initial coil be a 11" diameter or less in size. I don't recommend a coil less than 8" in diameter or similar if elliptical. So, any coil between 8" and 11" should be fine. Many of these can be found for sale at times on either the gold prospecting forums or their corresponding classifieds, or other classifieds. I have also seen some for sale on EBay.

I think you will find the sensitivity to be about the same on a mono and a DD but the DD will probably have less ground response, thus making it a better choice on a basic HH design.

As for adjustments, there are several options most of which depend upon just what you plan on using the HH to hunt for. As an example, if you plan on hunting for gold, then you will not need a long pulse length. Anything between 50 usec and 100 usec should work just fine. You should try to adjust the detector so you can sample as soon as possible. Using a ML compatible coil will make this easier since they are already maximized for short delays. If properly adjusted, you should be able to set the delay at 10 usec or so.

Do not use an excessive sample width. Try different values, but I suspect a sample width of 10 usec will be more than wide enough. At least, it is on my HH.

I think you will find the HH will outperform some of the other PI's available if built and adjusted for maximum sensitivity. You may need to make a few changes in values of components before it is all said and done, but those should not even be considered until you have a decent working PI.

This should be enough information to get you started.

Reg

[scott-bc]

Reg,

For now I will built it with the VCO option and build myself a mono coil. I will only be using for relic and beach hunting. Not for finding the small nuggets of gold. Have to learn how to us the machine first after its build.

I got the instruction on the forum on how to build a fast mono coil. I will also buy one of the coil housing also.

Scott

[Reg]

Hi Scott,

It is impossible to learn all there is to know about a PI before building one. Anyone who has learned to drive a car knows it was impossible to learn how to drive just by reading the book or by having someone tell you how to do it. You have to learn by doing. That is the advantage of building one.

The HH design is such that it is a good solid design that works well.

There isn't a dramatic change to making a HH a relic detector or a beach detector. For objects made of copper and silver, a longer pulse length is desired, so the initial adjustment could be much longer than that for gold.

It is still a good idea to try to build a coil that will allow for a short delay before sampling. The sooner one can sample, the greater the signal at the time of sampling. This results in greater depth capability.

Once you get started, you will have more questions that can be answered at that time.

Reg